No Voltage From The Battery Cables; Battery Voltage Issues - BMZ ESS Troubleshooting Manual

2.2

No voltage from the battery cables

1. Ensure the battery has been turned on.
A. The battery will never have any voltage present on the cables if it is not ON. You should
be able to measure voltage if battery is in Standby (blinking LEDs) OR the battery is
connected to an active inverter and is in operation.
2. Ensure the relay has closed.
A. You should hear a loud click just after turning the battery on. You should also check if the
relay is active via the service tool.
B. If the relay doesn't close, it's possible the battery is set to Slave mode. If it is, set it to
Single Mode if you want to check the voltage manually.
3. Ensure fuses have been inserted into the fuse holder and the fuse holder has been closed.
Alternatively, you can try measuring the voltage across the lower fuse terminals instead of
inserting fuses.
4. The battery is ON, relay is closed, fuses are inserted and there is still no voltage across the
terminals.
A. If above is verified and tested and there is still an issue, this very likely indicates some
internal issue. Please contact BMZ.
2.3

Battery Voltage Issues

There is always a very small drain on lithium batteries regardless of whether they are in use or not.
A. Battery MUST not sit for too long without being charged or it will drain beyond a recoverable
state. Please ensure the battery is installed no more than 6 months after purchase.
B.
Battery voltage MUST remain higher than 45V. See above, do not let it sit for too long.
Allowing the voltage to drop below 45V WILL void the warranty.
C. If the battery voltage drops below 45V, it will automatically turn off after 1 minute when
manually turned on. Even if the voltage is 1-2 volts above this, applying a load to the battery will
cause the voltage to drop rapidly.
D. If the battery voltage drops below about 30-32V, it will no longer be able to turn on and this
should be considered a point of no return. The battery will not be recoverable.
Page 6 of 14 Version 1.01
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ESS Troubleshooting Guide