Zero error code 25
12V Battery Low
What it means
12V Battery Low
12V auxiliary battery voltage low.
Warning — Monitor the situation, may self-resolve.
What to do
- 1Charge or replace 12V battery.
Code 25 on the other dash
The number alone is not enough. A Gen3 dash reads code 25 as 12V Battery Low; a Gen2 dash reads the same number as Contactor Open Warning. And the model name does not settle it: the S, SR, DS and DSR kept their names when they moved from the Sevcon dash to Cypher III in 2024, so it is the year that tells you which table applies.
Which bikes use this table
Cypher III dash: SR/F and SR/S (2020+), DSR/X (2023+), S/F, and the S, SR, DS and DSR from 2024, when those four moved to the FST platform.
Related codes
Other Gen3 Battery/BMS codes:
What the log file records for the same subsystem:
Questions
What does error code 25 mean on a Zero Gen3 dash?
12V Battery Low. 12V auxiliary battery voltage low. It is classed as warning: monitor the situation, may self-resolve.
What should I do about it?
Charge or replace 12V battery.
Does code 25 mean the same thing on a Gen2 Zero?
No. On a Gen2 dash, code 25 is "Contactor Open Warning" — a different fault entirely. The two tables share numbers but not meanings, so read the one that matches your dash, not your model name: the S, SR, DS and DSR kept their names when they moved to Cypher III in 2024.
See when this actually happened on your bike
A dash code tells you the fault; the log tells you the pack temperature, the state of charge and the ten minutes leading up to it.
Sources:
The code and its name are transcribed from Zero's own owner manuals; the severity, category and troubleshooting notes are ours. For official diagnostics, consult an authorized Zero Motorcycles dealer.