Bafang error 44: Battery single cell voltage too high
Bafang CAN systems (M400/M500/M600/M620, DP C18 CAN, 850C/860C CAN)Dealer neededDo not keep riding
One cell group in the pack is above its maximum voltage while the others are not. That is a balancing problem and a fire risk if ignored; the BMS blocks charging or discharging.
Likely causes
- Cell imbalance from age or a failed balancing circuit on the BMS
- Faulty charger pushing cells beyond 4.2V
- Damaged cell group
How to fix Bafang error 44
- Stop charging immediately and unplug the charger
- Let the pack rest for a few hours; some BMS units balance slowly when idle
- Have the pack checked by a shop or the battery manufacturer
- Do not open the pack or attempt to balance cells yourself
Go to a dealer if: Go to a shop or battery service immediately; an over-voltage cell is a safety risk.
Warranty: Battery warranty applies to balancing faults.
Typical cost: BMS replacement EUR/USD 80-150; cell group repair or pack replacement EUR/USD 300-700.
Warranty: Battery warranty applies to balancing faults.
Typical cost: BMS replacement EUR/USD 80-150; cell group repair or pack replacement EUR/USD 300-700.
Still stuck? Take a photo of the display and show it to a local e-bike workshop. Bring the bike's system name (e.g. Bosch Performance Line CX) and the exact code; that saves diagnostic time and money.
Frequently asked
Can I reset error 44?
Not safely at home. Let the pack rest and have it diagnosed.
Can I keep riding?
No. Store the battery in a safe place away from flammable material until checked.
Warranty?
Yes, unless the pack was physically damaged.
Related Bafang codes
Not an official Bafang document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.