Bosch error 620: Charger error
Bosch BES2 & BES3Fix at homeSafe to keep riding
The battery has detected a problem with the charger: wrong charger, faulty charger, or a bad connection at the charging socket. The bike rides normally; the battery just will not charge properly.
Likely causes
- Faulty Bosch charger or damaged charger cable
- Non-Bosch or wrong-model charger
- Dirty or damaged charging socket
- Charger plugged in while the system was switched on
- Charger overheated or on a faulty mains outlet
How to fix Bosch error 620
- Unplug the charger from the mains and the battery
- Check the charger plug and the battery socket for bent pins, dirt or moisture
- Try a different mains socket and let the charger cool if it is hot
- Switch the bike off before connecting the charger
- Try another genuine Bosch charger if you can borrow one
- If the code appears with a known-good charger, a dealer must test the battery's charging circuit
Go to a dealer if: A dealer is needed when a known-good genuine charger still triggers the code, which means the battery's charging circuit is at fault.
Warranty: A Bosch charger is covered for 2 years; damage from non-Bosch chargers is not, and can affect the battery warranty too.
Typical cost: A new Bosch charger is about 80-120 EUR/USD; otherwise usually free.
Warranty: A Bosch charger is covered for 2 years; damage from non-Bosch chargers is not, and can affect the battery warranty too.
Typical cost: A new Bosch charger is about 80-120 EUR/USD; otherwise usually free.
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 Bosch error 620 myself?
Yes. Disconnect the charger, restart the system and reconnect a working charger with the bike switched off.
Can I keep riding with error 620?
Yes. The drive keeps working normally with this code; it is a warning rather than a safety stop. Get it looked at when convenient, especially if it keeps coming back.
Is error 620 covered by warranty?
A Bosch charger is covered for 2 years; damage from non-Bosch chargers is not, and can affect the battery warranty too.
Related Bosch codes
Not an official Bosch document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.