Repair / Problems / Electric battery and charging / Charger shows a fault light or stays off

Electric battery and charging

Charger shows a fault light or stays off

OK to rideAlso called: charger red light, charger dead, charger not working, charger fan not running

The charger shows no light at all, or shows a fault light, or its lights never change to "charging". Each charger uses its own light codes. Ather, for example, says a blinking green light means charging and a solid red light means the charger is faulty; check your own manual. A charger can show a fault because of its own failure, because the mains supply is wrong, or because it cannot talk to the battery's BMS.

Is it safe to ride?

Yes, the bike can be ridden on the charge left. Stop using the charger if it is damaged, smells burnt or gets very hot.

Quick checks first

  • Is the wall socket working and switched on?
  • Is the mains plug and any fuse in the plug good (where plugs have fuses)?
  • Does the charger case smell burnt or show damage?
  • Are the charger vents blocked, or is it in the sun?

Diagnose it step by step

1Is the charger damaged, smelling burnt, or very hot?

2Plug the charger into a working wall socket, not connected to the bike. Does any light come on?

  • No light: try a different socket. If still nothing, check the plug fuse if your plug type has one. Still nothing: the charger has failed. Replace with an approved charger.
  • Light comes on: go to step 3.

3Connect to the bike. Does the light change to "charging"?

  • Yes: the charger works. If the battery still does not charge, see Battery will not charge.
  • Shows a fault: go to step 4.

4. Are the plug and port clean, dry and undamaged? Inspect the charge port and plug.

  • No: clean and dry, then retry.
  • Yes: go to step 5.

5Is the battery very hot or cold?

  • Yes: the charger may refuse until the battery is at a safe temperature. Wait and retry.
  • No: go to step 6.

6Ather suggests: switch off the mains, wait, switch on again and retry; then try the charger on another bike of the same model. Does it work on the other bike?

  • Yes: the fault is in your bike or battery (port, wiring, BMS). Diagnose a charging fault.
  • No: the charger is faulty. Replace it.

7. Charger fan runs but charging is slow or does not start? Ather says this often means a communication fault between charger and vehicle. Dealer or fleet workshop.

Causes, most likely first

Cause How to confirm Fix
No mains power Socket test Use a working socket
Dirty or wet port Visual Inspect the charge port and plug
Battery out of temperature range Hot or cold battery Wait
Charger failed No light on two sockets; fails on other bike Replace with approved charger
Communication fault with BMS Fan runs, no charge Dealer or fleet workshop

Related problems

Sources

Values marked K-Light 125 are for that reference bike. Use your own bike's manual for its values. Text CC BY-SA 4.0, Transitions Lab.