Endurance 5 — 51.2V 100Ah Rack-Mounted LiFePO4 Battery
Owner's & Operator's Manual V1.0
Terms Used in This Manual
- BMS
- Battery Management System — the circuit board that monitors and protects the cells
- SOC
- State of Charge — how full the battery is, expressed as a percentage
- SOH
- State of Health — remaining usable capacity compared to when new
- DOD
- Depth of Discharge — how deeply a battery is discharged per cycle
- LFP
- Lithium Iron Phosphate (LiFePO4) — the cell chemistry used in this battery
- OVP / UVP
- Over-Voltage / Under-Voltage Protection
- OCP / SCP
- Over-Current / Short-Circuit Protection
About This Manual
This manual is your reference for the Endurance 5 rack-mounted LiFePO4 battery system. It covers everything from unboxing to long-term maintenance, and it is intended for installers, technicians, and end-users who want to understand what they own.
Read this manual before you install, connect, or power on the battery. Lithium batteries store significant energy. They are safe when installed correctly and dangerous when they are not. Most failures in the field trace back to skipped steps during installation, not manufacturing defects.
Designed to Be Repaired, Not Replaced
The Endurance 5 is built for field serviceability. The BMS is a replaceable module that can be swapped by an authorized installer or qualified end-user without specialized tools. Replacement BMS boards are available through any Eneramp distributor. If the BMS fails in year 5 or year 15, you replace the board for a fraction of the cost of a new battery. The cells, housing, and wiring remain in service. This is the opposite of the industry norm, where a BMS failure means the entire battery goes to a landfill.
Liability Notice
Failure to follow the procedures in this manual may result in injury, death, or property damage. By installing and using this product, you acknowledge and accept all terms in this document. This manual is updated periodically; always verify you have the latest revision.
Specifications
Electrical
| Nominal Voltage | 51.2V (48V range) |
| Nominal Capacity | 100Ah |
| Energy | 5,120Wh (5.12 kWh) |
| Cell Chemistry | LiFePO4 (Lithium Iron Phosphate) |
| Cell Configuration | 16S (16 cells in series) |
| Max Continuous Discharge | 100A (1C) |
| Max Continuous Charge | 100A (1C) |
| Recommended Charge Current | 50A or less for daily cycling |
| Recommended Charge Voltage (Absorption) | 57.6V |
| Float Voltage | 55.2V |
| BMS High-Voltage Cutoff | 58.4V |
| BMS Low-Voltage Cutoff | 46V |
| BMS Low-Voltage Recovery | 48V |
| Self-Discharge | Less than 3% per month (BMS off) |
| Cycle Life | 6,000+ cycles at 80% DOD |
| Max Modules in Parallel | 64 |
| Series Connection | Not supported |
Listings & Certifications
| UL 1973 | Certified. Standard for Batteries for Use in Stationary, Vehicle Auxiliary Power and Light Electric Rail Applications. |
| UL 9540A | Certified. Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (cell and module level). |
| UL 9540 | Testing in progress. Full system-level Energy Storage System standard. |
| Shipping Classification | UN3480, Class 9 (Lithium Ion Batteries) |
A Note on UL 9540A vs. UL 9540
UL 9540A is a test method that evaluates whether thermal runaway in a single cell propagates to adjacent cells and modules. The Endurance 5 has passed this testing. UL 9540 is a broader, system-level standard that covers the complete energy storage installation including enclosures, ventilation, and fire suppression. Many AHJs are now requiring full UL 9540 listing for permitting. System-level testing is underway. Contact your distributor for the latest certification status if your AHJ requires UL 9540.
Intended Use
The Endurance 5 is designed for stationary energy storage applications: solar self-consumption, off-grid power, commercial backup, telecom backup, and similar installations where the battery charges and discharges at steady, predictable rates.
This battery is not designed for electric vehicle or traction applications.
Forklifts, golf carts, electric vehicles, marine propulsion, and other traction applications subject the battery to extreme surge currents during motor startup and acceleration. These transient loads can exceed the BMS protection thresholds by a wide margin in milliseconds, causing repeated short-circuit protection trips, BMS damage, or premature cell degradation. The Endurance 5's 100A continuous / 125A peak rating is designed for inverter-based loads, not the hundreds of amps that electric motors demand on startup. Damage resulting from use in traction applications is not covered under warranty, and creates safety risks that the BMS is not designed to manage.
Negative 48V Telecom Systems
The Endurance 5 primarily targets +48V systems (solar, off-grid, commercial backup), but it can also be deployed in -48V telecom environments. The battery uses a fully isolated design with no internal negative-to-ground bond, which makes it compatible with either polarity convention.
Breaker Placement Note for -48V Systems
Standard telecom practice places the breaker on the negative conductor (since negative is the "hot" side in a -48V system). The Endurance 5's front-panel breaker is on the positive conductor. The battery will function correctly in a -48V configuration, but the breaker position differs from typical telecom convention. Ensure your installation documentation reflects this, and verify that your external DC distribution and protection scheme accounts for the breaker being on the positive side.
Temperature
| Discharge Range | -20°C to 60°C (-4°F to 140°F) |
| Charge Range | 0°C to 45°C (32°F to 113°F) |
| Storage Range | -10°C to 45°C (14°F to 113°F) |
| Low-Temp Charge Protection | Yes — BMS blocks charging below 0°C |
| Internal Heaters | Yes — activate automatically below 0°C |
| Internal Temperature Sensors | 4 cell sensors + BMS sensor |
The Endurance 5 includes internal heaters for cold-weather operation. See the dedicated section for details.
Voltage vs. State of Charge
The table below provides an approximate relationship between pack voltage and state of charge at rest (no load, battery settled for at least 30 minutes). These values are for reference only.
| SOC | Pack Voltage | Cell Voltage | |
|---|---|---|---|
| 100% | 54.4V | 3.40V | |
| 90% | 53.6V | 3.35V | |
| 80% | 53.3V | 3.33V | |
| 70% | 53.2V | 3.33V | |
| 60% | 53.1V | 3.32V | |
| 50% | 53.0V | 3.31V | |
| 40% | 52.8V | 3.30V | |
| 30% | 52.5V | 3.28V | |
| 20% | 52.0V | 3.25V | |
| 10% | 50.4V | 3.15V | |
| 0% | 46.0V | 2.88V |
Why Voltage Is a Poor Indicator of SOC
Look at the table above. Between 80% and 30% SOC, the pack voltage only changes by about 0.8V total. That is the reality of LiFePO4's famously flat discharge curve: for the middle 50% of the battery's usable capacity, voltage barely moves. A reading of 53.1V could mean 60% or it could mean 40%, and the difference between those two states is 1,024Wh of stored energy.
This is why the BMS uses coulomb counting (tracking current in and out over time) to calculate SOC rather than relying on voltage alone. Do not use a simple voltmeter to determine how full the battery is. The LCD display and BMS communication provide accurate SOC readings. Voltage is only useful at the extremes: above 54V the battery is nearly full, below 50V it is nearly empty. Everything in between is a guess.
Physical
| Form Factor | 19″ EIA Standard Rack-Mount (3.5U) |
| Width | 442mm (17.4″) |
| Depth | 470mm (18.5″) |
| Height | 143.5mm (5.65″) |
| Weight | 45 kg (99 lbs) |
| Case Material | Powder-coated steel |
| Terminals | M8 bolt (positive and negative), accepts up to 4/0 AWG lugs |
| Terminal Torque | 10 ft-lbs |
| Communication Ports | CAN, RS485, Battery-Comm (parallel link) |
| Display | Built-in LCD with 4-button navigation |
Safety Instructions
Safety Labels
The following symbols appear on the battery and throughout this manual. Know what they mean before you begin.
| ⚠ | High Risk: May result in serious injury or death if not avoided. |
| ⚠ | Low Risk: May result in mild or moderate impairment if not avoided. |
| ⚡ | Disconnect battery terminals before commencing any work on the battery. |
| ☠ | Battery could explode or be severely damaged if dropped or crushed. |
| 🔥 | Battery may explode if exposed to open flames or extreme heat sources. |
| ⚓ | Grounding: System must be firmly grounded for operator safety. |
| ⬆ | This side should be facing up. |
| ⚠ | Handle with care to avoid damage. |
| 💧 | Keep dry. Do not expose to moisture or condensation. |
| 👶 | Keep the battery out of reach of children. |
| ⚡ | Do not short circuit the terminals. |
| ❌ | Do not reverse connection of the positive and negative terminals. |
Required PPE & Tools
Wear proper personal protective equipment at all times when working on or near the battery system.
Operator Requirements
Only trained and qualified personnel should install or service this product. The operator must be familiar with the system components, operating principles, and this manual. If you are an end-user performing your own installation, understand that this battery operates at voltages capable of causing serious injury. When in doubt, hire a qualified installer.
High Voltage Warning
The terminals on this battery carry 51.2V DC and can deliver over 100A of current. Accidental contact with both terminals simultaneously, or with a terminal and ground, can cause burns, arc flash, and electrical shock. Always use insulated tools. Always verify polarity before making connections. Never work on a live system without proper PPE.
Safety Do's and Don'ts
- DO NOT immerse in water. Store in a cool, dry environment.
- DO NOT expose to open flames or extreme heat. The battery may explode.
- Use only compatible charging equipment at the correct voltage and current settings.
- DO NOT reverse polarity. DO NOT connect directly to AC power. Avoid short circuits.
- DO NOT mix batteries from different manufacturers, different chemistries, or mix old and new batteries in the same parallel bank.
- DO NOT use a battery that is hot, swollen, deformed, or leaking.
- DO NOT puncture, drop, crush, or strike the battery.
- Only qualified personnel or authorized service agents should open the battery enclosure. Unauthorized modifications are not covered under warranty.
- If the battery emits an unusual smell, feels abnormally hot, or shows visible deformation, disconnect it immediately and contact your distributor.
- For long-term storage, charge and discharge every 3 months. Store at 50-60% SOC.
- Operate only within the temperature ranges specified in this manual.
- Batteries ship at approximately 50% SOC. Fully charge before first use.
- In case of fire: use carbon dioxide, dry chemical, or Class D fire extinguishers. Water can also be effective on lithium iron phosphate fires. Wear full PPE including respiratory protection.
Shipping & Receiving
What's in the Box
| Qty | Item | Notes |
|---|---|---|
| 1 | Battery Module | 51.2V 100Ah, ships at approximately 50% SOC |
| 1 | Communication Cable | CAT6, UL1007 rated |
| 1 | This Manual | Latest version always available online |
Power interconnects sold separately
The Endurance 5 does not ship with power cables. For parallel rack installations, use the E-190002 Laminated Copper Bus Bars, which are purpose-built for stacking batteries in the E-190001 5-Slot Battery Rack. For single-battery or custom installations, use appropriately rated cables (minimum 25mm² / 4 AWG for 100A continuous).
Inspection After Receipt
Every unit is tested before leaving the factory. When your battery arrives, inspect it before signing for delivery. If visible damage is present on the packaging, note it on the freight receipt and photograph it before opening.
- Outer packaging: Check for crushing, punctures, or water damage.
- Quantity and type: Verify everything in the packing list above is present.
- Smell test: Open the box and check for any strong chemical smell. A sweet or acrid odor can indicate internal cell damage from shipping impact. If present, do not power on the battery. Contact your distributor immediately.
- Terminal-to-case test: Using a digital multimeter set to DC voltage, measure from each terminal (positive and negative) to any bare metal on the battery case. If the meter reads any voltage, there may be internal damage. Stop immediately and contact your distributor.
Keep the Packaging
Retain the original packaging. If the battery ever needs to be returned for warranty service or relocated, the original packaging meets the transportation safety requirements for lithium batteries. Improvised packaging does not.
Installation Planning
Where you install the battery matters as much as how you wire it. Take the time to get this right; a poor location creates problems that no amount of good wiring will fix.
Protection from Physical Damage
Install batteries in a location that is not subject to physical impact. Garage installations should include bollards or other barriers to prevent vehicle collision. The battery weighs 45 kg (99 lbs) and can cause serious injury if it falls from a rack.
Moisture & Humidity
Extreme humidity and condensation degrade battery performance over time and can corrode terminals and BMS components. Avoid locations where condensation forms and coastal environments with salt spray. If the installation environment has high humidity, use a sealed or outdoor-rated enclosure.
Proximity to Equipment
Low-voltage DC systems are highly susceptible to voltage drop over long cable runs. A battery that reads 51.2V at the terminal may only deliver 48V at the inverter if the cables are too long or too thin. Keep batteries as close to inverters and charge controllers as possible. This minimizes cable losses and reduces the risk of premature low-voltage shutdown under heavy loads.
Temperature
The battery operates without active cooling in most environments. The ideal operating range is 15°C to 35°C (59°F to 95°F). The BMS will protect the cells outside safe ranges, but temperature extremes reduce available capacity and accelerate aging. Never install where ambient temperature exceeds 60°C (140°F).
Ventilation
The Endurance 5 uses a fanless design, which eliminates noise but means heat dissipation relies on natural convection. Maintain at least 100mm (4 inches) clearance between the cabinet and any wall. Do not block the sides or rear of the rack.
Lightning & Surge Protection
If your installation is in an area prone to lightning or power surges, install a DC-rated surge protection device (SPD) on the battery bus. Lightning does not need to strike your system directly to cause damage. A nearby strike can induce voltage spikes through ground potential rise, long cable runs, or coupled conductors that travel through your DC wiring and destroy BMS components, inverters, and charge controllers.
A quality DC surge protector installed between the battery bank and the inverter will clamp these transient voltages before they reach sensitive electronics. Products like the MidNite Solar MNSPD series are purpose-built for this application and are available in DC voltage ratings appropriate for 48V battery systems.
Where to install: Mount the SPD as close to the battery bank's DC disconnect as possible, on the inverter side. The shorter the cable run between the SPD and the equipment it protects, the more effective it will be. Follow the SPD manufacturer's installation instructions and ensure the grounding electrode conductor meets local code requirements.
Cold Weather & Self-Heating
The Endurance 5 includes internal heating elements that activate automatically when the battery temperature drops below 0°C (32°F). This is one of the most important features of the battery for cold-climate installations, and it works differently than most people expect.
The Purpose Is Readiness, Not Delay
The heaters are not a response to a charge request. They activate based on temperature alone, regardless of whether the battery is charging, discharging, or sitting idle. The goal is to keep the cells warm enough to accept charge at all times, so that when a charge source becomes available — solar panels producing in the morning, a generator starting, grid power restoring — the battery can begin absorbing energy immediately.
How the Heaters Work
When any internal temperature sensor detects a reading below 0°C, the heaters turn on and begin warming the cells using the battery's own stored energy. This happens whether the battery is actively being used or not. The heaters continue running until the cells are warm enough to safely accept charge.
Without self-heating, a frozen battery rejects charge entirely until the surrounding environment warms it up. In a cold climate, that could mean hours of lost solar production on a winter morning, or an extended outage where the battery sits full of capacity it cannot replenish. The heaters eliminate that delay.
Discharging in Cold
Discharging in cold conditions is safe for LFP cells. Capacity will temporarily decrease — sometimes by as much as 40% at extreme cold — but this capacity returns fully when the battery warms up. The heaters help mitigate this by keeping the cells above the worst-case temperature range even when no charge source is available.
Charging in Cold
Charging below 0°C is blocked by the BMS because lithium plating on the cell anodes can cause permanent, irreversible damage. This is true of every LFP battery, heated or not. The difference is that the Endurance 5 actively solves this problem rather than leaving it to the installer. As the heaters bring the cells above 0°C, the BMS allows charging to resume automatically. There is no user intervention required.
Energy Cost
The heaters draw a small amount of power from the battery itself. In sustained sub-zero conditions this parasitic draw is measurable but modest. The trade-off is straightforward: a small ongoing energy cost to stay charge-ready versus a potentially large energy loss from missing charge windows entirely.
Extreme Cold Installations
For installations in consistently sub-zero environments, consider insulating the battery cabinet to reduce heater energy consumption. The heaters are sized for intermittent cold exposure, not for keeping the battery warm in an uninsulated outdoor enclosure at -30°C indefinitely. In extreme climates, a temperature-controlled enclosure is recommended.
Mounting & Mechanical Installation
Rack Installation
The Endurance 5 is a standard 19″ EIA rack-mount form factor at 3.5U height. It fits the same racks as servers, networking gear, and other rack-mount battery systems. There is no proprietary mounting hardware.
Use full-depth rack rails or shelves. The front rack ears prevent the battery from sliding forward, but they are not designed to support the full 45 kg weight alone. Support the battery from below with a proper rail or shelf.
Load from bottom to top. Place the heaviest batteries at the bottom of the rack to prevent tipping. If your rack is not anchored to the floor, anchor it before loading batteries. Include earthquake brackets in seismic zones.
Secure each module. Insert the battery into the rack tray and fix with 4x M6x16 bolts per unit. Batteries can be stacked directly with no gap between them; the fanless design requires no airspace between units.
Physical Orientation
The Endurance 5 can be installed in any orientation except upside down (top lid facing the floor). Standard rack-mount is the most common, but the battery will also operate correctly mounted on its end, on its side, or face-down in custom enclosures and stationary installations.
The only prohibited orientation is inverted (top lid facing the ground). The internal cell arrangement and BMS mounting are designed with gravity in mind. Operating the battery upside down can compromise internal connections and is not supported.
Mobile installations: For vehicles, trailers, and marine applications, mount the battery flat (standard rack orientation) to minimize the effects of vibration and sudden movement. Secure the battery firmly to prevent shifting.
Wheeled Racks and Rolling Battery Banks
Putting 45 kg batteries on wheels sounds convenient until you think about what happens next. A fully loaded 5-slot rack weighs over 225 kg (500 lbs). That is enough mass to seriously injure someone if it rolls, tips, or shifts during an earthquake, a collision, or just because a wheel lock failed on a sloped floor.
Beyond the crush and tip-over hazard, rolling racks create electrical risks. Movement stresses terminal connections, loosens bolted joints over time, and can dislodge communication cables. A loose power connection on a 100A circuit creates heat, arcing, and potential fire. A lost communication cable means the BMS can no longer coordinate with the inverter, which can lead to overcharge or over-discharge conditions.
If you must use a wheeled rack, lock all casters before energizing the system. Never move a rack while the batteries are connected and powered. Treat it as a permanent installation that happens to be relocatable when fully de-energized. Re-torque all terminal connections to 10 ft-lbs and verify all communication cables after every move.
Lifting & Handling
At 45 kg (99 lbs), this battery requires two people minimum for safe handling. Wear steel-toe boots and non-slip gloves during installation. Use a forklift or cart for moving multiple units. Never invert the battery or stack more than 3 units high without a rack.
Electrical Installation
Step 1: Grounding
Connect one end of the grounding cable to the GND terminal on the battery chassis. Connect the other end to the grounding copper strip of the rack or cabinet. Verify a solid, low-resistance connection. This is not optional.
Step 2: Power Connection
Single battery: Connect the battery terminals to the inverter or DC disconnect using appropriately rated cables (minimum 25mm² / 4 AWG for 100A continuous). Red to positive, black to negative. Torque M8 terminal bolts to 10 ft-lbs.
Multiple batteries in parallel: Use the E-190002 laminated copper bus bars to interconnect batteries within the rack. See the section for complete bus bar installation details.
Step 3: Verify Polarity
Before energizing the system, use a digital multimeter to verify that positive connects to positive and negative connects to negative at every junction. A reversed connection will cause immediate, severe damage to the BMS and is not covered under warranty.
For parallel systems (multiple batteries), see the dedicated section for DIP switch addressing, communication cabling, and wiring guidance.
Emergency Disconnect (Shunt Trip)
The Endurance 5 supports an optional external emergency disconnect switch that can shut down all batteries in the system with a single button press. If your inverter supports rapid shutdown (RSD), this same signal can trigger that function as well, bringing the entire energy storage system to a safe state in seconds.
How It Works
The emergency disconnect ties into the battery communication system through an open Battery-Comm port using a standard Cat 5/6 ethernet cable. When the stop button is pressed, an emergency stop signal is sent over Pins 3 and 6 of the RJ45 connector. Every battery in the communication chain receives this signal and shuts down its BMS, disconnecting all power output.
This is not a software feature that can be overridden or delayed. The signal goes directly to the BMS hardware. When someone hits that button, the batteries stop.
Installation
Connection
Wire the ESS disconnect switch to a standard Cat 5/6 cable using Pins 3 and 6. Plug the cable into any available Battery-Comm port in the system. In a parallel configuration, any battery in the daisy chain will relay the signal to all others.
Switch Placement
Mount the disconnect switch in a location that is easily accessible in an emergency but protected from accidental activation. Near the main entrance to the battery room or equipment area is typical. The switch should be clearly labeled.
Rapid Shutdown Integration
If your inverter supports rapid shutdown (RSD), the emergency stop can trigger this function as well. Consult your inverter documentation for RSD wiring requirements, as these vary by manufacturer.
Code Compliance
The ESS disconnect switch should be lockable. Check with your Authority Having Jurisdiction (AHJ) and current NEC code for specific requirements in your installation. Many jurisdictions now require an accessible emergency disconnect for battery energy storage systems. Your installer is responsible for ensuring compliance with all applicable local, state, and national electrical codes.
Disconnecting means: Because the Endurance 5's emergency disconnect performs a complete rapid shutdown of the entire battery system (all batteries de-energize, not just a single circuit), it can often serve as the system-level disconnecting means required under NEC Article 706.12. This is a significant compliance advantage over systems that only provide a single-unit breaker. Confirm with your AHJ whether the rapid shutdown capability satisfies their disconnecting means requirements for your specific installation.
After an Emergency Shutdown
Once the emergency disconnect has been triggered, the system will not restart on its own. You must manually clear the stop condition (reset or unlock the switch), then follow the standard to bring the system back online. Inspect the system for the condition that triggered the emergency stop before restarting.
Parallel Battery Systems
The Endurance 5 supports up to 64 batteries in parallel, scaling from 5.12 kWh to 327 kWh. This section covers everything specific to multi-battery installations: addressing, communication cabling, power wiring, and what to expect during the first few charge cycles.
Primary and Follower Batteries
In every parallel system, one battery is the primary (ID #1) and the rest are followers. The primary is the only battery that communicates directly with the inverter. Follower batteries send their data to the primary via the Battery-Comm inter-link, and the primary aggregates everything and relays it upstream. The inverter only ever talks to one battery. This is important to understand because it means the communication cable to the inverter always comes from Battery #1, regardless of how many units are in the system.
DIP Switch Address Assignment
Each battery must have a unique address set via the 6-position DIP switch on the front panel. The switches use binary encoding: down is "ON" (1), up is "OFF" (0). SW1 is the least significant bit (value 1) and SW6 is the most significant bit (value 32). Duplicate addresses will cause complete communication loss across the entire system.
Always power off the battery before changing DIP switch settings. After changing the address, power cycle the battery for the new setting to take effect.
| ID | SW1 | SW2 | SW3 | SW4 | SW5 | SW6 |
|---|---|---|---|---|---|---|
| 1 * | ON | OFF | OFF | OFF | OFF | OFF |
| 2 | OFF | ON | OFF | OFF | OFF | OFF |
| 3 | ON | ON | OFF | OFF | OFF | OFF |
| 4 | OFF | OFF | ON | OFF | OFF | OFF |
| 5 | ON | OFF | ON | OFF | OFF | OFF |
| 6 | OFF | ON | ON | OFF | OFF | OFF |
| 7 | ON | ON | ON | OFF | OFF | OFF |
| 8 | OFF | OFF | OFF | ON | OFF | OFF |
| 9 | ON | OFF | OFF | ON | OFF | OFF |
| 10 | OFF | ON | OFF | ON | OFF | OFF |
| 11 | ON | ON | OFF | ON | OFF | OFF |
| 12 | OFF | OFF | ON | ON | OFF | OFF |
| 13 | ON | OFF | ON | ON | OFF | OFF |
| 14 | OFF | ON | ON | ON | OFF | OFF |
| 15 | ON | ON | ON | ON | OFF | OFF |
| 16 | OFF | OFF | OFF | OFF | ON | OFF |
| 17 | ON | OFF | OFF | OFF | ON | OFF |
| 18 | OFF | ON | OFF | OFF | ON | OFF |
| 19 | ON | ON | OFF | OFF | ON | OFF |
| 20 | OFF | OFF | ON | OFF | ON | OFF |
| 21 | ON | OFF | ON | OFF | ON | OFF |
| 22 | OFF | ON | ON | OFF | ON | OFF |
| 23 | ON | ON | ON | OFF | ON | OFF |
| 24 | OFF | OFF | OFF | ON | ON | OFF |
| 25 | ON | OFF | OFF | ON | ON | OFF |
| 26 | OFF | ON | OFF | ON | ON | OFF |
| 27 | ON | ON | OFF | ON | ON | OFF |
| 28 | OFF | OFF | ON | ON | ON | OFF |
| 29 | ON | OFF | ON | ON | ON | OFF |
| 30 | OFF | ON | ON | ON | ON | OFF |
| 31 | ON | ON | ON | ON | ON | OFF |
| 32 | OFF | OFF | OFF | OFF | OFF | ON |
| 33 | ON | OFF | OFF | OFF | OFF | ON |
| 34 | OFF | ON | OFF | OFF | OFF | ON |
| 35 | ON | ON | OFF | OFF | OFF | ON |
| 36 | OFF | OFF | ON | OFF | OFF | ON |
| 37 | ON | OFF | ON | OFF | OFF | ON |
| 38 | OFF | ON | ON | OFF | OFF | ON |
| 39 | ON | ON | ON | OFF | OFF | ON |
| 40 | OFF | OFF | OFF | ON | OFF | ON |
| 41 | ON | OFF | OFF | ON | OFF | ON |
| 42 | OFF | ON | OFF | ON | OFF | ON |
| 43 | ON | ON | OFF | ON | OFF | ON |
| 44 | OFF | OFF | ON | ON | OFF | ON |
| 45 | ON | OFF | ON | ON | OFF | ON |
| 46 | OFF | ON | ON | ON | OFF | ON |
| 47 | ON | ON | ON | ON | OFF | ON |
| 48 | OFF | OFF | OFF | OFF | ON | ON |
| 49 | ON | OFF | OFF | OFF | ON | ON |
| 50 | OFF | ON | OFF | OFF | ON | ON |
| 51 | ON | ON | OFF | OFF | ON | ON |
| 52 | OFF | OFF | ON | OFF | ON | ON |
| 53 | ON | OFF | ON | OFF | ON | ON |
| 54 | OFF | ON | ON | OFF | ON | ON |
| 55 | ON | ON | ON | OFF | ON | ON |
| 56 | OFF | OFF | OFF | ON | ON | ON |
| 57 | ON | OFF | OFF | ON | ON | ON |
| 58 | OFF | ON | OFF | ON | ON | ON |
| 59 | ON | ON | OFF | ON | ON | ON |
| 60 | OFF | OFF | ON | ON | ON | ON |
| 61 | ON | OFF | ON | ON | ON | ON |
| 62 | OFF | ON | ON | ON | ON | ON |
| 63 | ON | ON | ON | ON | ON | ON |
| 64 | OFF | OFF | OFF | OFF | OFF | OFF |
* ID 1 = Primary battery (connects to inverter). ON = switch down. OFF = switch up.
Power Interconnects (Bus Bars)
The Endurance 5 system uses laminated copper bus bars (E-190002) rather than traditional cables for parallel power connections. This is a deliberate design choice that solves a real problem with multi-battery wiring.
Why Bus Bars Instead of Cables?
Traditional cable wiring forces current to flow through each battery to reach the next one in the chain. The batteries closest to the inverter become bottlenecks, carrying not just their own current but the current of every battery above them. This creates uneven loading, accelerated wear on the lower batteries, and voltage drop that reduces system efficiency.
Bus bars create true parallel current paths up the front face of the rack. Each battery connects directly to the bus bar at its own terminal, and every battery has an equal-resistance path to the inverter. The result is even current distribution across all modules.
Construction
The bus bars are laminated tinned pure copper (1″ × 1/8″ cross-section) rated for 454A. The laminated design uses multiple thin copper layers rather than a solid bar. This makes them extremely flexible while maintaining full conductivity. They absorb thermal expansion and vibration without fatigue or stress fractures, and they can be bent to sharp angles by hand without tools or special equipment.
Stacking & Spacing
The Endurance 5 is a 3.5U tall module. The bus bars are designed to span approximately 2.5U of clearance between batteries in a standard rack configuration. The bus bar from the battery above overlaps the bus bar from the battery below at each terminal, with two M8 bolts compressing the copper-to-copper joint at each overlap point.
Because the bus bars are ultra-flexible, they also support zero-clearance stacking where batteries are mounted directly on top of each other with no gap. Simply bend the bus bars to accommodate the tighter spacing. The laminated construction handles this without any loss of conductivity or mechanical integrity.
Joint Protection
Each bus bar ships with a protective cover that insulates the stacked overlap joint after installation. Once the M8 bolts are torqued and the copper-to-copper connection is made, snap the cover over the exposed joint. This prevents accidental contact with live conductors and protects the connection from debris and moisture.
Installation
Bus bars mount directly on the battery front faces. There are no crimps, lugs, or cable management to deal with. They are designed specifically for the E-190001 5-Slot Battery Rack. One set of bus bars handles the positive side, another set handles the negative side. Torque all M8 terminal bolts to 10 ft-lbs.
Inverter Connection
From the bottom (or top) of the bus bar stack, run appropriately sized cables to the inverter or DC disconnect. Size these main cables for the total system current: the number of batteries multiplied by the expected maximum draw per battery.
Communication Cabling
There are two separate communication connections in a parallel system. They serve different purposes and use different ports.
Battery-Comm (Battery to Battery)
The Battery-Comm port on each unit is a daisy-chain RS485 link that connects the batteries to each other. Use the included CAT6 communication cable to connect Battery #1's Battery-Comm port to Battery #2's Battery-Comm port, then Battery #2 to Battery #3, and so on through the chain.
This link carries status data (voltage, current, temperature, SOC, faults) from each follower battery up to the primary. The batteries cannot transfer power to each other through this cable. It is data only.
RS485 or CAN (Primary Battery to Inverter)
A separate communication cable connects the primary battery (ID #1) to the inverter. Use the RS485 or CAN port on the primary battery, depending on which protocol your inverter supports. This is the uplink that carries the aggregated data from all batteries to the inverter.
Only the primary battery connects to the inverter. Follower batteries should have nothing plugged into their RS485 or CAN ports.
What to Expect: First Charge Cycles
When connecting batteries that are at different states of charge, the system will self-equalize through the parallel power connections. The higher-SOC batteries will discharge slightly into the lower-SOC batteries until they reach equilibrium. This is normal and expected.
Automatic Cell Balancing
Each battery's BMS has an independent cell balancer that activates near the top of charge. When charging approaches 100%, cell voltages rise rapidly. The balancer bleeds energy from the fullest cells so that all 16 cells within each module charge together evenly.
It is normal for the BMS to trigger over-voltage protection (OVP) during the first several charge cycles as the cells settle. This is the balancer at work, not a fault. It typically takes 10 to 15 full charge cycles for all cells to reach perfect balance. You will know the cells are balanced when the voltage spread (visible on the LCD cell voltage screen) is within 30mV.
SOC Variation Between Batteries
It is completely normal for parallel batteries to show different SOC readings during any given charge or discharge cycle. Variations of up to 10% are common and are not cause for concern. This does not mean a battery is providing less than its rated capacity.
Several factors cause this: slight differences in wire resistance between each battery and the bus bar, variations in internal cell resistance between modules, temperature differences across the rack, and normal cell-to-cell variation. Even a small difference causes one battery to temporarily take more of the load (or accept more charge) than its neighbors. Over the full duration of a charge or discharge cycle, this balances out naturally. The battery that was lagging picks up the load at the other end of the cycle. The voltage differences created as batteries diverge in SOC will eventually cause them to converge at some point in the cycle, and the full rated kWh capacity of the bank is recovered.
When to investigate: If the SOC spread between batteries exceeds 10% and does not improve after a week of normal daily cycling (charge to 100%, discharge, repeat), check for unequal cable lengths, a loose terminal connection, or a temperature difference between modules (top of rack running hotter than bottom, for example).
Low-Draw Systems and Parasitic Drain
When a battery is under very light load (less than 0.5A), the BMS current sensor cannot accurately measure the draw. The SOC will decrease over time without the BMS registering any meaningful discharge. This is normal behavior for the current sensing hardware, but it has real consequences in certain installations.
Seasonal and Low-Use Installations
This is particularly important for cabins, vacation homes, and seasonal properties where the system may sit for weeks or months with only a small inverter idle draw. A typical inverter draws 1-2A when idle. In a system with many batteries in parallel, that draw is split across all units. With 10 or 15 batteries sharing a 2A idle load, each battery sees a fraction of an amp, well below the BMS measurement threshold.
Over weeks and months, this unmeasured parasitic drain slowly empties the batteries. The BMS still reports the SOC it last calculated, so the owner has no warning. They arrive in spring to find batteries at critically low voltage, BMS units in lockout, and potentially cells damaged from prolonged deep discharge.
The solution is straightforward: If your system will be unattended for extended periods, either ensure a charge source remains active (even a small solar panel on a charge controller) or shut down the batteries completely using the . A powered-off battery self-discharges at less than 3% per month and will safely hold its charge for months.
Weekly Full Charge Recommendation
We recommend charging the battery to 100% at least once per week during active use. This serves three purposes: it recalibrates the SOC reading (which drifts over time without a known reference point), it gives the cell balancer an opportunity to work (balancing only activates near the top of charge), and it prevents the gradual SOC drift caused by sub-threshold parasitic loads from accumulating into a real problem.
Power Up & Shutdown
Understanding Inrush Current
Inverters and charge controllers contain large capacitor banks on their DC bus. When you first apply voltage to these capacitors, they appear as a momentary short circuit. LiFePO4 batteries have very low internal resistance, which means they can deliver enormous instantaneous current into that apparent short. This "inrush current" can damage circuit breakers, fuses, BMS components, and the inverter's capacitors.
This is the single most common cause of installation damage, and it is entirely preventable. Follow the power-up procedure below exactly as written.
Power-Up Procedure
The order matters. The built-in pre-charge circuit activates when the BMS soft switch powers on. For pre-charge to work, the entire DC path from the battery terminals through to the inverter's capacitor bank must already be complete. That means external disconnects and the front-panel breaker must be ON before you press the ON/OFF button. If you activate the BMS with the external breakers still open, pre-charge runs against an open circuit and accomplishes nothing.
- 1
Inspect the system. Check all wiring for loose connections, short circuits, and reversed polarity. Fix any issues before proceeding.
- 2
Verify all batteries are powered off. No LED lights should be illuminated on any unit. If any battery is on, press and hold the ON/OFF button until the display and LEDs turn off. The BMS must be off on every unit before proceeding.
- 3
Turn on all external DC breakers and disconnects. This completes the DC path from the battery terminals to the inverter. The inverter's capacitors are now connected but uncharged. This is safe because the battery BMS is still off and no voltage is being applied yet.
- 4
Turn on the front-panel breaker on each battery unit. Still no voltage is applied because the BMS soft switch is off.
- 5
Press the ON/OFF button on Battery #1 (primary). This activates the BMS, which engages the pre-charge circuit. Current flows through the pre-charge resistor to slowly charge the inverter's capacitors before the main power circuit enables. Wait for the LCD to display and the SOC LEDs to illuminate.
- 6
Power on remaining batteries one at a time by pressing their ON/OFF buttons.
- 7
Verify no ALM (alarm) LEDs are lit. If the alarm LED is on, do not proceed. See the for troubleshooting.
- 8
System is now ready for use. The inverter should be receiving battery voltage and communication (if configured for closed-loop).
Shutdown Procedure
- Remove all loads and shut down inverters, charge controllers, and other connected equipment.
- Turn off all external DC breakers and disconnects.
- Turn off the front-panel breaker on each battery.
- Press and hold the ON/OFF button on each battery until the display and LEDs turn off.
The BMS will automatically enter sleep mode after approximately 24 hours without any current flow. Manual shutdown conserves battery power during extended periods of inactivity.
Front Panel & LED Indicators
Panel Layout
| No. | Item | Description |
|---|---|---|
| 1 | Rack Mount Ears | Brackets for securing to 19″ EIA rack |
| 2 | Handle | Front carrying handle for rack insertion |
| 3 | Terminal (+) | Positive power terminal (M8 bolt) |
| 4 | Breaker | Front-panel DC disconnect switch |
| 5 | LCD Display | Shows voltage, current, SOC, temperature, cell data |
| 6 | ID DIP Switch | Sets unique address for parallel communication (1–64) |
| 7 | ON/OFF | Powers the BMS on and off |
| 8 | ALM | Alarm LED — indicates a fault condition |
| 9 | CAN Port | CAN bus communication interface to inverter |
| 10 | Battery-Comm | RS485 inter-battery parallel link port |
| 11 | GND | Chassis ground bonding point |
| 12 | RESET | Emergency BMS restart button |
| 13 | SOC LEDs | 4 green LEDs, each representing ~25% charge |
| 14 | RUN LED | Indicates BMS is active and operating |
| 15 | RS485 Port | RS485 communication interface to inverter |
| 16 | Terminal (-) | Negative power terminal (M8 bolt) |
DIP Switch (item #6): Sets the battery address for parallel systems. See the section for the full DIP switch address table and communication cabling instructions.
LED Indicator Reference
| Battery State | RUN | ALM | SOC LEDs |
|---|---|---|---|
| Shutdown / Sleep | OFF | OFF | OFF |
| Standby (idle) | ON | OFF | Shows charge level |
| Normal Charge | Slow flash | OFF | Shows charge level |
| Normal Discharge | Slow flash | OFF | Shows charge level |
| Charge Warning | Slow flash | Medium flash | Shows charge level |
| Discharge Warning | Slow flash | Medium flash | Shows charge level |
| Fully Charged | ON | OFF | All 4 ON |
| Fully Discharged | OFF | OFF | OFF |
| Over-Temperature Protection | OFF | Slow flash | OFF |
| Over-Current Protection | OFF | Slow flash | OFF |
Slow flash: 1 second interval · Medium flash: 1.5 second interval · Each SOC LED represents approximately 25% state of charge.
Communication Port Pinout
RS485 Interface
| Pin 1, 8 | RS485 B- (T/R-) |
| Pin 2, 7 | RS485 A+ (T/R+) |
| Others | Not connected |
CAN Interface
| Pin 4 | CAN_H |
| Pin 5 | CAN_L |
| Others | Not connected |
Communication & Inverter Setup
Closed Loop vs. Open Loop
The Endurance 5 supports two modes of operation with your inverter:
Closed Loop (Recommended)
The BMS communicates directly with the inverter via CAN or RS485. The BMS tells the inverter exactly how much current to deliver, when to stop charging, when to slow down, and when something is wrong. This is the safest and most efficient configuration. It also enables the BMS to properly balance cells by ramping charge current down rather than cutting it off entirely.
Open Loop (Setpoints)
For older inverters without communication support, or DC loads that cannot communicate, you program static voltage and current setpoints into the inverter. The BMS still protects the battery, but the inverter has less information about battery state. Use the setpoints in the table below.
Open Loop Setpoints
If your inverter does not support communication, program these values:
| Charge Current (daily cycling) | 50A or less per battery |
| Charge Current (fast charge / generator) | Up to 95A per battery |
| Absorption Voltage | 57.6V (acceptable range: 57.6V – 58.4V) |
| Absorption Time | 15 minutes |
| Float Voltage | 55.2V |
| Low Voltage Shutdown | 48V |
Why 48V Shutdown Instead of 46V?
The BMS will not cut power until 46V, but if you set your inverter's shutdown at 46V, you risk the battery shutting down before the inverter does. Some inverters require battery voltage to be present before they can turn on, which creates a restart problem. Setting the inverter cutoff 2V higher gives you a safety buffer.
About Charging to 100%
There is a common misconception that LiFePO4 batteries should only be charged to 80-90%. This advice applies to other lithium chemistries (NCA, NMC) but not to LFP cells. LiFePO4 cells do not experience the same stress at high SOC that other chemistries do.
Charging to 100% regularly is actually important for this battery because the BMS cell balancer only activates near the top of charge. Without regular full charges, cells slowly drift out of balance, reducing usable capacity. Charge to 100% at least once per week.
Supported Communication Protocols
The communication protocol is selected via the LCD screen. Set the battery ID to 64, power on, hold the BACK button for 5 seconds to enter protocol selection, choose the protocol, press ENTER, then restart the battery with the correct ID.
RS485 Protocols
| Code | Inverter |
|---|---|
| P01-GRW | Growatt |
| P02-SCH | Schneider |
| P03-INH | Inhenergy |
| P04-VOL | Voltronic |
| P05-SRN | Srne |
| P06-CVTE | CVTE |
| P07-LUX | Luxpower |
| P08-PWR | CVTE |
| P09-DY | Deye |
CAN Protocols
| Code | Inverter |
|---|---|
| P01-GRW | Growatt |
| P02-SLK | Sol-Ark |
| P03-DY | Deye |
| P04-MGR | Megarevo |
| P05-VCT | Victron |
| P06-LUX | Luxpower |
| P07-SMA | SMA |
| P08-INH | Inhenergy |
| P09-SOL | Solis |
| P10-AFO | Afore |
| P11-STU | Studer |
| P12-MUST | Must |
| P13-SUN | SAJ |
| P14-PLY | Pylon |
| P15-TRB | Turbo |
| P16-HUB | Hubble |
LCD Screen & PC Software
LCD Navigation
The built-in LCD turns off after 30 seconds of inactivity. Press any button to wake it. The four navigation buttons below the display work as follows:
| UP | Page up / scroll through options |
| DOWN | Page down / scroll through options |
| BACK | Return to previous screen |
| ENTER | Confirm selection / enter submenu |
Main Screen
The home screen displays: Battery ID, operating status (Charging/Discharging/Idle), SOC percentage, system time, total capacity, pack voltage, and active communication protocol.
Available Screens
Cell Voltages
Press ENTER from the main screen. Displays individual voltage of all 16 cells across 2 pages (cells 1-9 on page 1, cells 10-16 on page 2). Use UP/DOWN to navigate between pages. When cells are properly balanced, the voltage spread should be within 30mV.
Temperature
Select the thermometer icon and press ENTER. Shows readings from all internal temperature sensors (4 cell sensors + BMS board sensor).
Protocol Selection
Only accessible when battery ID is set to 64. Power on, hold BACK for 5 seconds, select the appropriate RS485 or CAN protocol for your inverter, press ENTER, then restart with the correct ID.
PC Software (BMS_tools)
A Windows PC application is available for advanced diagnostics and monitoring. Contact your distributor for the latest version. Connect via RS485-to-USB cable with baud rate set to 9600. The software provides:
- Real-time BMS monitoring (voltage, current, temperature, SOC)
- BMS parameter viewing and configuration
- Operation data logging with export capability
- Communication debugging tools
Maintenance
Clearing Protection States
When the BMS detects a condition outside safe operating parameters, it triggers a protection state and shuts down or limits the affected function (charging, discharging, or both). The ALM LED will illuminate or flash. The protection must be cleared before the battery returns to normal operation.
Over-Voltage Protection (OVP)
Triggered when a cell exceeds the safe charge voltage. The BMS stops charging. To clear: The protection resets automatically once cell voltage drops back into the safe range (the BMS cell balancer will bleed the high cell down). If this happens repeatedly during initial charging, it is normal. The cells are balancing. Allow the process to continue over 10-15 cycles.
Under-Voltage Protection (UVP)
Triggered when a cell drops below the safe discharge voltage. The BMS stops discharging. To clear: Apply a charge source. Once cell voltage rises above the recovery threshold, the BMS re-enables discharge automatically. If the battery has been deeply discharged and will not respond, try a low-current charge source (5-10A) to gently bring the cells back above the minimum threshold.
Over-Current Protection (OCP)
Triggered when discharge current exceeds the rated 100A. The BMS limits or cuts output. To clear: Reduce the load below the rated current. The protection resets automatically once current drops to a safe level. If this trips frequently, the system loads exceed what the battery bank can deliver. Add more batteries in parallel or reduce peak demand.
Short Circuit Protection (SCP)
Triggered by a sudden, extreme current draw (typically a wiring fault or inrush current event). The BMS immediately disconnects output. To clear: Turn off the front-panel breaker. Wait 60 seconds for the protection to reset internally. Fix the cause of the short circuit. Then follow the standard . If SCP triggers again after two restart attempts, there is a persistent wiring fault or the inverter's capacitor bank exceeds the pre-charge capability. Do not continue attempting to restart.
Over-Temperature Protection (OTP)
Triggered when internal temperature sensors detect unsafe heat (or cold, for charge protection). To clear: Allow the battery to return to the safe operating temperature range. The protection resets automatically. If charging was blocked due to cold, the internal heaters will warm the cells and charging will resume without intervention. If triggered by heat, improve ventilation or reduce load.
Manual Reset (RESET Button)
If the BMS enters a state that does not clear automatically, use the RESET button on the front panel (item #12). Press briefly with a small screwdriver or similar tool. This forces a full BMS restart. If the underlying condition persists, the protection will re-trigger. The RESET button does not override protections; it restarts the BMS so it can re-evaluate the current state of the cells.
Troubleshooting
| Problem | Likely Cause | Solution |
|---|---|---|
| Inverter cannot communicate with battery | Wrong communication port, cable, or battery ID | Verify cable connections, check DIP switch address, confirm correct protocol selected |
| No DC output from battery | Front-panel breaker is off, or battery voltage too low | Close breaker; if voltage is low, apply charge |
| Battery discharges too quickly | Battery not fully charged, or capacity reduced | Charge to 100% and run a full discharge test; check cell balance via LCD |
| Battery will not charge to 100% | Charge voltage too low, or cells are unbalanced | Verify absorption voltage is set to 57.6V; allow 10-15 charge cycles for initial cell balancing |
| ALM LED stays on continuously | Short circuit or wiring fault detected | Turn off breaker, disconnect power cables, inspect all wiring for shorts or damage |
| Output voltage is unstable | BMS operating abnormally | Press RESET button; if problem persists, power cycle the battery |
| ALM flashes 20x, SOC1 LED on | Cell voltage imbalance detected | Charge to 100% and allow BMS to balance; check individual cell voltages on LCD |
| ALM flashes 20x, SOC2 LED on | Temperature sensor fault | Contact distributor for temperature sensor cable replacement |
| ALM flashes 20x, SOC3/4 LED on | BMS hardware fault | Contact distributor for BMS replacement |
| Different SOC between parallel batteries | Normal — batteries equalize over time | Allow system to run; batteries will converge within several charge cycles |
Routine Maintenance Schedule
| Item | What to Check | Interval |
|---|---|---|
| Power Cables | Inspect for mechanical damage, verify insulation sleeves intact, check for looseness (re-torque if needed), examine copper bus bar for discoloration. | 6 months |
| Communication Cables | Verify RJ45 terminals are secure and fully seated. Check for cable discoloration (indicates heat damage). | 12 months |
| Cabinet & Ventilation | Clean dust from battery surfaces, rack, and surrounding area. Verify 100mm wall clearance is maintained. | 6-12 months |
| System Health Check | Review voltage, current, and temperature on LCD. Verify switches and breakers function. Check cell voltage spread via LCD (should be within 30mV when balanced). | 6 months |
| Capacity Test | Perform a light-load shallow charge/discharge cycle. Compare SOC and SOH readings via PC software to baseline. Depth of discharge should not exceed 20% for this test. | 3-6 months |
BMS Replacement
The BMS in the Endurance 5 is a field-replaceable module. If the BMS develops a fault (indicated by persistent ALM codes, SOC3/4 LED patterns, or erratic behavior that does not resolve with a reset), it can be replaced without discarding the battery.
Ordering a Replacement
Contact your Eneramp distributor to order a replacement BMS board. We recommend keeping a spare on hand for critical installations. Replacement boards ship in EMP-protective packaging and are compatible with all Endurance 5 production runs.
Who Can Replace It
BMS replacement can be performed by an authorized Eneramp installer or a qualified end-user comfortable working with low-voltage DC electrical systems. Specialized tools are not required beyond what is listed in the section of this manual.
Procedure
Fully shut down the battery and disconnect all power and communication cables before opening the enclosure. The BMS board disconnects from the cell harness and terminal connections and lifts out. The replacement board installs in the same position. After reassembly, the new BMS will automatically detect the cell pack and begin normal operation. Allow 2-3 full charge cycles for the new BMS to calibrate SOC against the existing cells.
The cells outlast the electronics. LiFePO4 cells are rated for 6,000+ cycles and have an expected service life of 15-20+ years. Electronics age differently. By making the BMS replaceable, the Endurance 5 ensures that a component failure in year 10 is a repair, not a disposal.
Serviceability & End of Life
Most battery manufacturers design products that are assembled once and never opened again. When something fails, the entire unit is discarded. The Endurance 5 is designed differently. Every major component can be individually diagnosed, serviced, and replaced, extending the useful life of the battery far beyond what sealed, disposable designs allow.
Replaceable Components
BMS Board
The most likely component to need replacement over the battery's lifetime. The BMS board can be swapped in the field without specialized tools. Replacement boards are stocked by Eneramp distributors. See the procedure in the Maintenance section.
Cell Modules
Individual cells or cell groups can be replaced by an authorized service center if a cell fails or degrades significantly below the rest of the pack. This is a more involved repair than a BMS swap but it means a single bad cell does not condemn the entire battery.
Internal Wiring & Connectors
All internal connections use standard connectors and wiring that can be inspected, repaired, or replaced. Nothing is permanently potted or epoxy-sealed.
Breaker & Terminal Hardware
The front-panel DC breaker and M8 terminal hardware are standard components that can be sourced and replaced if damaged.
Modules with Bolted Cells
Beginning with upcoming production batches, the Endurance 5 will transition to a bolted cell construction. In bolted cell modules, the individual cells are mechanically fastened rather than welded, making cell-level service significantly easier. A bolted cell pack can be disassembled with standard hand tools, allowing individual cells to be tested, replaced, or reconfigured without cutting or re-welding bus work.
Bolted cell modules are backward-compatible with all existing Endurance 5 racks, bus bars, and communication systems. If your unit has welded cells (current production), it remains fully supported. The BMS, housing, terminals, and all external interfaces are identical between welded and bolted variants.
End of Life
LiFePO4 cells are rated for 6,000+ cycles at 80% depth of discharge. In a typical daily-cycling solar installation, that translates to over 16 years of service before the cells reach 80% of their original capacity. They do not stop working at 80%; they continue to operate with gradually reduced capacity for years beyond that point.
Because the BMS is replaceable and cells can be individually serviced, the realistic end of life for an Endurance 5 is not when the first component fails. It is when the cells have degraded to the point where the remaining capacity no longer meets the needs of the application, and cell replacement is no longer economically justified.
Disposal & Recycling
Do not dispose of lithium batteries in household waste or general landfill. LiFePO4 batteries contain materials that can be recovered and recycled. When the battery has reached the end of its useful service life:
- Contact your Eneramp distributor for recycling guidance specific to your region.
- Many jurisdictions have dedicated lithium battery recycling programs and drop-off facilities.
- The steel enclosure, copper bus work, and electronic components are all recyclable through standard e-waste channels.
- Fully discharge the battery to the lowest safe voltage before transport to a recycling facility.
Storage Guidelines
Short-Term (Under 3 Months)
- Fully charge the battery before storage.
- Store in a dry, cool environment free of corrosive gases.
- Temperature: 10°C to 45°C (50°F to 113°F).
- Humidity: 30% to 90% (non-condensing).
- Keep away from direct sunlight and strong electromagnetic fields.
Long-Term (Over 3 Months)
- Store at 50-70% SOC (not full, not empty).
- Temperature: 20°C to 35°C (68°F to 95°F).
- Humidity: 35% to 65% (non-condensing).
- Charge the battery once every 6 months to prevent irreversible capacity loss from deep self-discharge.
- Check terminal voltage before returning to service; charge fully before use.
Lithium iron phosphate cells self-discharge very slowly (less than 3% per month with the BMS off), but the BMS itself draws a small parasitic load when left on. Always shut down the BMS before long-term storage to maximize shelf life.
Commissioning Checklist
Use this checklist during initial installation to verify that every step has been completed. Each item references a section of this manual for detailed instructions.
Pre-Installation
Mechanical Installation
Electrical
Communication (Parallel Systems)
Power Up & Verification
After Commissioning
Allow the system to run through 2-3 full charge/discharge cycles before evaluating performance. Cell balancing takes 10-15 cycles to fully complete on new batteries. SOC variation between parallel units is normal during this period and will converge over time.
NEC Code Reference (NFPA 70)
The following NEC articles apply to the installation of the Endurance 5 battery system. This is a reference guide for installers and AHJs, not a substitute for reading the applicable code. Always verify requirements with the current edition adopted by your jurisdiction, as code adoption varies by state and municipality.
| Article | Subject | Relevance to This Battery |
|---|---|---|
| Article 706 | Energy Storage Systems | Primary governing article for ESS installations. Covers disconnecting means, overcurrent protection, circuit sizing, grounding, and signage requirements for battery systems. |
| 706.7 | Listing Requirements | ESS equipment must be listed (UL 9540 or equivalent). The Endurance 5 is UL 1973 and UL 9540A certified; UL 9540 system-level testing is in progress. |
| 706.12 | Disconnecting Means | A disconnecting means must be provided and be accessible. The front-panel breaker serves as the unit-level disconnect. The optional emergency disconnect (shunt trip) performs a complete rapid shutdown of all batteries and may satisfy the system-level disconnecting means requirement. Confirm with your AHJ. |
| 706.15 | Connection to Energy Sources | Covers how the battery connects to inverters, charge controllers, and the grid. Applies to both open-loop and closed-loop configurations. |
| 706.20 | Overcurrent Protection | Overcurrent protection is required for battery circuits. Size external breakers/fuses based on the total system current and conductor ampacity. |
| 706.30 / 706.31 | Circuit & Conductor Sizing | Conductors must be sized for the maximum current of the system. For parallel batteries, this is the sum of all units’ maximum output. |
| 706.40 | Grounding & Bonding | The battery chassis must be bonded to the equipment grounding conductor. The Endurance 5 provides a dedicated GND terminal for this purpose. |
| 706.50 | Signage | Requires labels identifying the ESS, its voltage, and the location of disconnecting means. Required at the battery, at the main service panel, and at any point of interconnection. |
| Article 480 | Storage Batteries (General) | General requirements for battery installations including terminal protection, disconnecting means, and ventilation. Article 706 takes precedence for ESS but 480 fills gaps. |
| 480.7 | Disconnecting Means | Requires a disconnecting means within sight of the battery system. The emergency disconnect switch (shunt trip) satisfies this when installed. |
| 480.9 | Battery Interconnections | Covers conductor sizing and protection for cables between batteries in a parallel bank. Relevant to bus bar and cable installations. |
| Article 110.26 | Working Space | Minimum working clearances must be maintained around the battery system for safe maintenance access. Typically 36″ in front of equipment rated under 150V to ground. |
| Article 250 | Grounding & Bonding | General grounding requirements. Defines grounding electrode conductors, bonding jumpers, and equipment grounding. Consult for system-level grounding design. |
| Article 705 | Interconnected Power Sources | Applies when the battery is part of a solar-plus-storage or other interconnected system. Covers backfeed protection and utility interconnection. |
Other Applicable Standards
| NFPA 855 | Standard for the Installation of Stationary Energy Storage Systems. Some AHJs reference this in addition to or instead of NEC Article 706. Covers fire safety, spacing, ventilation, and signage for ESS installations. |
| IFC 1207 | International Fire Code section on Energy Storage Systems. Adopted by some jurisdictions as the fire safety standard for ESS. Covers installation, commissioning, and decommissioning requirements. |
| UL 9540 | Standard for Energy Storage Systems and Equipment. The system-level listing standard that many AHJs now require for permitting. See the section for current status. |
Installer Responsibility
Code compliance is ultimately the responsibility of the installer and the system designer. Eneramp provides this reference as a starting point, but local amendments, state adoptions, and AHJ interpretations vary. Always confirm requirements with your local building department or electrical inspector before beginning installation. When in doubt, consult a licensed electrical engineer.
Warranty
Within the specified warranty period, free repair and replacement services are provided for product damage or functional failure resulting from manufacturing defects. A valid purchase invoice or proof of purchase is required. The warranty does not cover:
- Damage from improper installation, reversed polarity, or inrush current
- Damage from use outside specified operating parameters
- Products that have been opened, disassembled, or modified
- Normal wear, cosmetic damage, or damage from natural disasters
For warranty claims, contact your authorized Eneramp distributor with your proof of purchase and a description of the issue. Do not return the battery without prior authorization.