DC isolation between battery terminals and earth is below the safe threshold (typically <50kΩ). BMS ALM LED shows red steady.
Common causes
Damaged DC cable insulationMoisture in battery DC output connectorBattery enclosure damaged allowing moisture ingress
What to check
STEP 1
Disconnect battery from inverter. Use an insulation resistance tester (500V DC) to test resistance between positive terminal and earth, and negative terminal and earth. Any reading below 1MΩ indicates a fault
STEP 2
Inspect DC output cable and connector for damage or moisture. Check battery enclosure for physical damage
Escalate if
DC wiring tests OK but fault persists — internal battery insulation fault. Do not re-energise — safety risk. Escalate immediately
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