Troubleshooting - 12v Accessory Battery

Connect 120v to the Charge Port

If the LED on the side of the battery pack still will not illuminate, it's a clear sign the 12v battery is dead. Let's check to see if the 12v battery charger is doing its job. Connect the e-bike charge port to a 120v wall receptacle. Make sure the battery switch is in the 'I' or on position.

  • Does the RED LED turn on when the charge port is connected?
Yes - Let it charge for five minutes and then disconnect the charge port. If the LED goes out, the battery is not holding a charge and may need to be replaced.
No - Possible bad charger. Continue

Remove the Right Tank Clam

Check 12v Battery Charger Plugs

Before we identify the charger as the problem, let's check one other item. The 12v battery pack has two 8" cables coming out of it. One is the 12vdc supply voltage cable (white 2-pin modular connector) that goes to the relay pack.

The second cable is the 12v battery charger cable with a small black plug. That's what you're looking for. It's located along the right side of the center tube, just below the seat post. Check to make sure this plug is connected to the matching charger plug. Plug and unplug the connector to ensure good contact. Note: I tape them so they don't disconnect.

⚠️ Important: Plug the charge port back into the 120v receptacle, or the charger won't be on.

  • Does the RED LED lit on the side of the battery pack now?
Yes - It's possible the 12v battery charger cable had a bad connection. See if the battery will charge now. If you think that might have been the problem, click here. If the battery won't hold a charge, it will need to be replaced.
No - (Abnormal) Continue

Issue:  Possible 12v Battery -or- 12v Battery Charger Problem

At this point, it could be either the battery or the charger. To test the charger for proper operation, use a digital multimeter to measure the voltage from the charger. You should measure approximately 12vdc on the connector from the charger.

If there is 12v on the charger's connector, but the red led on the battery pack doesn't light with the switch in either position, then the battery pack is bad and must be replaced. Order a new replacement 12v battery pack w/charger here.

Note: If the charger looks good, there may be no reason to disassemble the lower unit clam. Replace only the battery and see if that solves the problem. Since the battery and charger come as a set, keep the new 12 battery charger as a spare.

If there is not 12vdc on the charger's connector, the 12v charger must be replaced.


There is the slight possibility that is has become unplugged from the lower-unit 120v plug strip (but very doubtful), but either way the lower-unit left clam must be removed.

12v Battery Charger w/ LED - Plugged into 120v Power Strip

Replacing the 12v Accessory Battery Charger

Remove the lower unit left clam to access the battery charger. If you haven't done this procedure before, please visit the 'Disassembly' section of this manual and then return to this point.

Check to see if the 12v battery charger is plugged in and its LED charge light is 'on'. If the LED is not on and it's plugged in to 120v, then the charger is bad. The battery and associated charger come as a set. Order a new replacement 12v battery pack w/charger here.