Any Evidence of Cause in This Photo?

[the_horak]

Looking at these mosfets and the neighboring circuit, anyone have an idea of what might have caused this damage? I didn't use the controller very long. 48v 30A controller with 52V 30A batteries.

 

[neptronix]

What kind of controller is it - no name chinese or something that actually costs money?
What kind of average continuous wattage were you putting through it?

 

[the_horak]

What kind of controller is it - no name chinese or something that actually costs money?
What kind of average continuous wattage were you putting through it?

I'd think no-name. It's a KT controller but I don't know if it's actually made by them. It was around $60 for just the controller. I'd say a solid 1200-1600W at full throttle and I sometimes will keep it like that for a few minutes straight. Should I even bother trying to fix this? I have soldering and testing skills, but I don't know if this is worth the effort with all the surface burns

 

[neptronix]

Some really cheap controllers can just be designed badly. It sounds like the amp rating might have been overstated, or some low quality FET blew up due to bad QC.

You may want to try replacing the FET and any other components that seem dead to try to revive it - but personally, i'd recommend buying a higher quality controller over messing with these mystery chinese units that offer no end user support. maybe you can fix them, but you may discover new problems along the line.

 

[the_horak]

... I'd recommend buying a higher quality controller over messing with these mystery chinese units that offer no end user support. maybe you can fix them, but you may discover new problems along the line.

Agreed. Who knows what the next weak link with this one is, and the SMCs are pretty wrecked... The controller market is so confusing though... I want 28-30A with 52v batteries for a geared hub motor, so one with a speed sensor wire in the hall sensor wiring plug. I ride my bike like an e-moped sometimes so I need some decent performance to hit around 34 mph. What is the best way to search the market but stick to quality brands/vendors?