Thanks for the part number. For those interested,
here is the datasheet for them. Some interesting points:
- Rdson is pretty low at ~0.002 ohms. Paralleling 12 of these brings the total value to ~0.00016 ohms.
- 50A rating
- 30v rating. Maybe this is why some of these don't work well at 6s lipos? 6s under a full charge would be 25.2v, which is quite close to the max rating of 30v. However, a look at the "3 Safe Operation Area" graph, you can see that it is good for 50A up to 20v. Past 20v, the safe current goes down. Hmm, interesting.
- Dissipation up to ~105W. Of course this assumes an adequate heatsink. The derating graph ("1 Power Dissipation") shows that it is 105W up to 25C. Above 25C, the power is derated about 0.9W/degreeC.
Was the thermal pad sticky at all? There has to be
something to hold the FETs against the heatsink. If you don't want to use a thermal epoxy of some kind, you could get some
thermal tape instead. It won't work quite as well, but I understand your point about the epoxy being permanent.
Edited for stupid spelling error