Help! Pendleton Somerby Electric Bike (Dec 2019) Battery fully charged but no power to wheel

[DennisTheMenace]

I have a Pendleton Somerby Electric Bike, bought in Dec 2019.
One morning this week, the power no longer went to the wheel.
There are a full 4 lights on the controller, so I can see that the battery is fully charged.
The cable from the battery has come out a bit (the grommet is now outside the battery housing), no idea why.
Any clues as to what the prblem could be?
My initial though is that there is a loose cable inside the battery housing, not the cable that goes to the controller, but the one to the wheel.
When I get a couple of free hours I will (attempt) to open up the casing, check hte connections (if I can see/recognise them) and reseat the grommet.

 

[Sturmey]

Two question that if answered might give an additional clue.
1. Are there any additional lights flashing ? ( e.g. The Low, Med or High lights flashing give fault message/codes)
2.There is a 'walk assist' thumb button function on the 790 unit. Pushing this button normally activates the motor slowly and weakly (independent of the pedal sensor.) Is this the case?

 

[Nealh]

If you have power to the control panel/display then the battery wire/cable connection is fine (but will need the grommet reinserted ). The battery wire/cable has no effect on the hub motor as the hub motor wiring only connects to the motor controller box.
If the battery wire grommet has been pulled slightly for what ever reason then there could be a possible couple other issues to check.

As mentioned if the display shows no weird light sequences then look elsewhere for the problem.
1. The hub motor cable connection /connector on the front or rear fork, make sure the connector is fully pushed home.
2. The PAS sensor set up on the Bottom bracket may be misaligned , so again needs checking depending on the PAS set up used.

 

[DennisTheMenace]

Two question that if answered might give an additional clue.
1. Are there any additional lights flashing ? ( e.g. The Low, Med or High lights flashing give fault message/codes)
2.There is a 'walk assist' thumb button function on the 790 unit. Pushing this button normally activates the motor slowly and weakly (independent of the pedal sensor.) Is this the case?

Thank you for your reply. I will check and get back to you.

 

[DennisTheMenace]

If you have power to the control panel/display then the battery wire/cable connection is fine (but will need the grommet reinserted ). The battery wire/cable has no effect on the hub motor as the hub motor wiring only connects to the motor controller box.
If the battery wire grommet has been pulled slightly for what ever reason then there could be a possible couple other issues to check.

As mentioned if the display shows no weird light sequences then look elsewhere for the problem.
1. The hub motor cable connection /connector on the front or rear fork, make sure the connector is fully pushed home.
2. The PAS sensor set up on the Bottom bracket may be misaligned , so again needs checking depending on the PAS set up used.

Thank you for your reply. I will check and get back to you.

 

[DennisTheMenace]

Thank you for your reply. I will check and get back to you.

Two question that if answered might give an additional clue.
1. Are there any additional lights flashing ? ( e.g. The Low, Med or High lights flashing give fault message/codes)
2.There is a 'walk assist' thumb button function on the 790 unit. Pushing this button normally activates the motor slowly and weakly (independent of the pedal sensor.) Is this the case?

Thanks for your help.
There are no additional flashing lights.
There is a 'walk assist' thumb button function on the bike.
Pushing it turned the back wheel.
from what you said it sounds like the pedal sensor is not working properly.
Do you know how I can test that?

 

[DennisTheMenace]

If you have power to the control panel/display then the battery wire/cable connection is fine (but will need the grommet reinserted ). The battery wire/cable has no effect on the hub motor as the hub motor wiring only connects to the motor controller box.
If the battery wire grommet has been pulled slightly for what ever reason then there could be a possible couple other issues to check.

As mentioned if the display shows no weird light sequences then look elsewhere for the problem.
1. The hub motor cable connection /connector on the front or rear fork, make sure the connector is fully pushed home.
2. The PAS sensor set up on the Bottom bracket may be misaligned , so again needs checking depending on the PAS set up used.

Thanks for your help.
There are no loose wires within the housing, all connectors apppear to be fully connected, no misalignment with the arrows.
From reading Sturmey's post, I am thinking that it is the hub sensor that may be at fault.

 

[Sturmey]

...... I am thinking that it is the hub sensor that may be at fault.

Are you sure you don't mean pedal sensor. That the thing located on the inside of the front chainwheel. It consists of a magnetic disk and a sensor with a small red led light in my case. The light normally come on at startup but flashes when you pedal. It actually went faulty in my case due to water ingress into the small unit. The sensor itself may not be faulty in your case but wont work if the magnetic disk has got disturbed say due to the chain coming of the bike . So check that the disk is not damaged and turns with the chainwheel and that there is a gap (I think about 3mm) between disk and sensor.

 

[Nealh]

If the walk assit works then the Hall sensors in the hub are fine , your issue will likely be the pedal assist sensor on the bottom bracket .It is easy to check that the gap and sensor aligns with the magnets as they pass.