EG4 › Problems
EG4 battery won't turn on, shuts itself off, or shows an alarm light
An EG4 battery won't turn on, shuts itself off, or shows its alarm light. This page covers what the lights and codes mean, what to check first, and the causes behind it.
What the lights mean
| What you see | What it means |
|---|---|
| ALM light always on (LifePower4) | Short circuit. Turn off the battery breaker and check all the cabling. |
| ALM light on at start-up and nothing outputs (LifePower4) | A short-circuit style fault that blocks any output until the breaker is switched off and on. Seen when the battery was turned on before the breaker to the inverter was closed. |
| ALM light flashes 20 times with one SOC light on (LifePower4) | With SOC1 on: unbalanced voltage within a cell. With SOC2 on: unbalanced temperature. With SOC3 or SOC4 on: the BMS is damaged. |
| ALM light with charge or discharge over- or under-temperature shown in BMS Tools | Temperature protection. Power off the battery and let it cool down or warm up before starting again. |
| No lights on after the battery ran low (LifePower4) | The BMS is in low-voltage protection and sleep mode. Charge it at once or it will go back to sleep within minutes. |
| RUN light on but the battery deeply discharged (LifePower4) | The battery voltage is too low to start the BMS. |
| All lights solid on a LifePower4 after a firmware update was interrupted | The update failed because power or the comm cable was lost during it. Running the automatic updater again recovered the battery. |
Error codes that go with this problem
| Code | What it means |
|---|---|
| Protection (battery display) | The battery's management system has locked itself out in protection mode. No code or cause is shown. |
| Discharge MOS fault alarm (BMS Tools, solid red ALM light) | A discharge MOSFET protection fault reported by the battery's BMS Tools software. |
| M3 Rx failure (18kPV screen) | The inverter's M3 processor is not receiving data from the DSP. |
What to check first
- Note which battery lights are on or flashing. If the ALM light stays on, turn off the battery breaker and check all the cabling, as EG4's LifePower4 guide says.
- Note what happened just before: cold weather and a clicking noise, a V2 battery added to a V1 stack, or the battery turned on before the breaker to the inverter was closed.
- To clear a start-up fault, turn the breakers off, wait a second and turn them back on. Then start in order: breaker to the inverter closed first, then the battery on, then the inverter.
- For an over- or under-temperature alarm, power off the battery and let it cool down or warm up before starting it again.
- If a LifePower4 has no lights after running low, charge it at once. Otherwise it goes back to sleep within minutes.
- If it stays dead or in protection, the wiring, battery ID switches and settings need checking. Once those are ruled out, EG4 or the distributor replaces a failed battery under warranty.
The causes and the fixes
Partners see the causes behind this problem, most common first, the checks that tell them apart, and the fix for each, with part numbers and recent prices when a part is involved.