Power Cutting Out

[stever1957]

Hello there again.

My Big Bear's power has been cutting out intermittently.

I'll be riding along, then lose all power, yet the display is still on.

On one occasion, I could see the battery charge indicator decrease, step by step, from five to one.

When this happens, I have power from neither the pedal assist nor the throttle.

Continuing to try the throttle, or restarting at the display has, up to now, corrected the issue.

 

[Woosh]

Please get in touch with support@wooshbikes.co.uk Andy will help you sort it.

 

[saneagle]

Hello there again.

My Big Bear's power has been cutting out intermittently.

I'll be riding along, then lose all power, yet the display is still on.

On one occasion, I could see the battery charge indicator decrease, step by step, from five to one.

When this happens, I have power from neither the pedal assist nor the throttle.

Continuing to try the throttle, or restarting at the display has, up to now, corrected the issue.

It sounds like a knackered battery. Does it happen randomly or only when you draw high power?

 

[stever1957]

Randomly.

I rode one mile this morning and it happened four times.

The display stayed on the whole time.

 

[Woosh]

It sounds like a knackered battery. Does it happen randomly or only when you draw high power?

his display stays on, suggesting overheated controller. If the battery cuts out, the LCD would be off.

 

[stever1957]

As regards the battery, I had it upgraded by Jimmy a few years ago. 21700 cells and new BMS.

 

[stever1957]

his display stays on, suggesting overheated controller. If the battery cuts out, the LCD would be off.

You may remember that the controller is a secondhand one I got from Andy.

This was the thread:

https://www.pedelecs.co.uk/forum/threads/big-bear-motor-gone.45983/

 

[Woosh]

how well did the second hand controller do?

I rode one mile this morning and it happened four times.

it's possible that the battery voltage sags too much when under load. Still, swap out the controller is still the best first step to diagnose the fault.

 

[stever1957]

how well did the second hand controller do?

it's possible that the battery voltage sags too much when under load. Still, swap out the controller is still the best first step to diagnose the fault.

Well, the secondhand controller has been good until now (although I never could get the speedometer working).

Any idea if I can still get one of those controllers?

 

[saneagle]

Randomly.

I rode one mile this morning and it happened four times.

The display stayed on the whole time.

In that case you must have a short or a bad connection on the motor cable. When the controller can't turn the motor with the correct commutation pulses, the current goes sky high and the voltage goes down. First thing to do is check all the connectors of the motor cable at both ends. If the connectors or wires at the controller end melted, you'd get those symptoms. You could also get it if the motor connector is not in all the way to the line.

 

[stever1957]

Reply to Andy at Woosh:

"So, I alligned the terminals, rode down the road, then no power, no display.

Noticed a wire inside melted.

Fuse gone, changed it - still all dead.

Put battery no 2 in - all working.

Rode a mile down the road - all okay. "

Actually, battery no 2 was the one with new BMS, not the problem one.

I'll see if I can send this dodgy one to Jimmy.

Thanks!