Self made pedelec does not work...

[Yves]

Hi,

I bought a conversion kit on alibaba(motor + controller) My friend's electric motor was broken and he didnt want to repair it. So I got my battery from him. I toke off his controller and solded mine to the battery case.

Once I had put the battery in its case, I smelled something burned and saw some smoke coming out of the battery...(not much, very little)

What am i doing wrong? Is the battery not fit for the controller/ system? According to me i have connected the wires in the correct way.

In the attachment you can see some of the pictures i have taken.

Regards

 

[Yves]

Damn, looks like positive and negative on the controller were switched... got it connected now in the right way but nothing happens anymore... i suppose my battery is broken..?

 

[wheeliepete]

Damn, looks like positive and negative on the controller were switched... got it connected now in the right way but nothing happens anymore... i suppose my battery is broken..?

Yes, you have most likely blown the BMS board in the battery and your controller I'm afraid. Depending on your soldering abilities, the BMS is replaceable, so the battery should be saveable.

 

[vfr400]

The battery is probably OK. It's the controller that blows, and they're dead cheap. Are you sure that the smoke came from the battery and not the controller?

Check the battery with a meter to see if there is the correct voltage on the terminals/connector.

 

[Nealh]

As the controller is in the little compartment before the battery it will appear that the battery might be smoking, what occurs with reverse polarity of the wiring is you will have blown the inlet capacitor. If you open the controller you will find the large capacitor blown apart and fluff everywhere.
The battery and BMS should be fine as they were not direct in line.

Yes in pic #3 it is clear Red to Black & Black to Red, no real harm done just needs a new controller and that polarity connection reversed.

 

[guerney]

What a nightmare! Seems wire colours can never be trusted, best test polarity first next time before bringing forth the juice:

 

[Yves]

Ok thanks guys, i also believe my controller is blown up instead of the battery.
On the battery, there is a button to check if the battery is charged. When i push the button i can see the battery is still fully charged...

 

[vfr400]

Ok thanks guys, i also believe my controller is blown up instead of the battery.
On the battery, there is a button to check if the battery is charged. When i push the button i can see the battery is still fully charged...

It's a good sign, but not conclusive. You must check the output wires/connector with a meter.

 

[Yves]

I measured 41 Volts output. So i guess my battery still works? Why is the output bigger than the theoretical 36Volt?

Regards

 

[soundwave]

its 36v flat and 41v fully charged

 

[Yves]

Oh i see thanks !

 

[Nealh]

36v is the nominal battery capacity or approx. 45/50%, the max charge is 42v and the minimum discharge is approx. 32v.

 

[Yves]

It works!!! I did my first test drive today in my street. Thanks a lot guys! Couldn't achieve this without the help of this forum!

Regards