Generic / Chinese displays error E12: Battery (BMS) communication fault

What it means

The battery's electronics are not communicating. On generic displays the meaning of a code depends on the controller's communication protocol; this meaning is from the display maker's manual for this protocol.

Likely causes

• Battery not seated
• Dirty battery contacts
• Battery fault

Symptoms

• E12 shows

How to fix it

1. Remove and refit the battery firmly.
2. Check contacts are clean and dry.
3. Never open the battery.
4. If the code stays, take the bike to your dealer or an e-bike repair shop.

How urgent is it?

Needs checking.

Applies to

• SW900 (King-Meter LCD-SW900)
• S866
• GD01
• GD02

More Generic / Chinese displays codes

• E09 Controller fault
• E10 Communication fault (display receiving)
• E11 Communication fault (display sending)
• E13 Headlight fault
• 01_info Throttle fault
• 03_info Motor hall sensor fault

All 48 Generic / Chinese displays codes →