How to tell voltage rating on speed/voltage controller?

[mjp8081]

I want to get the voltage rating from a controller without printed info on the casing. I basically just have the board and info printed on it. You guys know what to look for? There is one unused solder point labeled "VO:24"

I have this 36v electric skateboard that I suspect has the wrong controller installed

 

[fechter]

If you can read the numbers off the power transistors, you can determine the maximum voltage rating for those. Also look at the main capacitor voltage rating.
Unfortuantely, this does not tell you the whole story, as the voltage regulator and low voltage cutout won't have a voltage rating printed on them.

Maybe if you can post a picture of it we can guess better.

What makes you think it's the wrong one?

 

[mjp8081]

Thanks for that. I will get a picture.

What makes me suspicious is that I was told by the guys who sell these in the US that they experimented with using a 36v LiFePO (out of the gate at ≤43v) instead of the SLAs and it overloaded the controller. I want to upgrade to LiFePO, but not if the same thing is going to happen. So I kinda poked around inside, saw all the tell-tale signs of deadline-driven/cost-cutting manufacturing (I dont use the word "Chinese") like cheap components and sloppy soldering. I thought that perhaps a cheaper or more abundant 24v controller would handle 36v SLAs, so they went with that to cut their costs. The "VO:24" imprint was what got me thinking--but I didnt get a complete look at the board, just a peek inside.

 

[mjp8081]

Here are some pix:

http://picasaweb.google.com/mjp808/M6Controller?authkey=Gv1sRgCLXT5PjxxMjSugE#

Now I see that solenoid(?)--does that cinch it? Those 3 capacitors are labled 50v.

 

[TylerDurden]

It might help to get the number off the parts that look like the one indicated. Those should be the FETs.