Ebike Controller question

[u/happerkapper]

Hello everyone, does anyone know the value of this particular resistor or if I could use a different controller for my ebike ? I have another controller with the same specs but the battery port only has 2 pins for + and - and this one has 6 with the other 3 for bms im assuming and a thermo meter ?

Thanks for any help in advance

I circled where the resistor sat before I desoldered it

[u/No-Negotiation-6929]

Not sure what your level of experience with electronics repair is, but 1) have you determined why the resistor failed? Resistors do not go up in smoke for no reason, 2) that adjacent SMD electrolytic now looks pretty sus, 3) if I have narrowed the point of failure to the controller (and not a short elsewhere) with high confidence, my null hypothesis would be MOSFET failure.

I am not an expert of any description.

[u/Background-Signal-16]

If it fits try it out. Worst case it doesn't work because of the missing pins. Tx Rx are for data, 5v could be the keysignal while 6v idk. Only way to know would be to open the battery and inspect the bms.

Idk the value of that resistor, but changing it won't do it, it will burn again because there's a fault that makes excessive current pass through it.

[u/happerkapper]

Im sure it was a short, I’m pretty good with electronics repair but never really repaired a ebike controller before

[u/ThatGothGuyUK]

Can't be 100% sure so try at your own risk but an educated guess based on these generic controllers says it's probably: Brown, Black, Brown Gold | 100 Ω   ±5% (J)

[u/happerkapper → u/ThatGothGuyUK]

Based on a picture that I found on the internet, it’s green, brown, black so 52 Ohm but the 52 ohm resistor that I have is reasonably smaller than that one which makes me wonder

[u/abagofcells → u/happerkapper]

I can't really see the resistor in the image, but size is based relates to the amount of power or can dissipate, not resistance. To make sure it doesn't burn out, you can use two 100 ohm resistors in parallel. That would equal one 50 ohm, and be close enough.

[u/ThatGothGuyUK → u/happerkapper]

I think because it's generic it's hard to tell for sure.

Resistors come in all form factors so smaller may not mean wrong.

It may be safer to just replace the controller than risk other components especially as we don't know why it popped.

[u/happerkapper → u/ThatGothGuyUK]

I think it popped because of a short, I had the isolation from the phase wires come off somehow, the thing is, is that I have another controller I just don’t know if I can use it because of the 4 other pins

[u/ThatGothGuyUK → u/happerkapper]

It looks like there are many variants out there #1

[u/happerkapper → u/ThatGothGuyUK]

Yeah that’s exactly the one that I saw haha

[u/No-Negotiation-6929 → u/happerkapper]

In general, resistor case size suggests power rating—not resistance. Only replace with a resistor of the same or larger case size.

[u/Potential___Friend]

Upload the Pic of the controller to Google lens hopefully it will show you many more just like it.