Is there a Quark 125B thermal problem?

[zeropointbug]

Hmmm, maybe the aluminum slab is for durability reasons maybe? Instead of having the FET's right up at the case...

I also checked the FET, from what i can see the FET's are Infineon made, and are rated at 30V, and 100A capability each... thats the page i found anyways.

I wonder when ESC makers will utilize heat pipes to dissipate the heat, VERY effective, and makes for a lot of options as far as setup.

Do you think i will be okay with running 5s2p A123 cells with a 7.5 lb 1/8 emaxx buggy conversion, as far as thermals go?

[zeropointbug]

Now wait, i found another page that says 50A. And 2.2mOhm, and it looks like them too.

They are called "OptiMOS 2 power transistor"

They drain at 50A even at 100 degrees celcius, and 200A pulse at 25 degrees

Power dissipation is rated at 104watts, wow.

[BrianG]

Neweuser: Well, you can donate it me if you'd like. :) If you do what I did, you will only need one 3mm thick slab. Regular AS adhesive has some capacitive properties and might cause problems if it drips onto the legs of the FETs (especially the gate lead). AS has another type that is non-conductive and non-capacitive. However, I was careful and used the normal stuff and haven't had any problems. I'm sure the use of the padding was somewhat determined by ease of working on it. I know mine is useless for warranty work now, but I personally think it was worth it for the thermal performance compared to what it was before the mod.

zeropointbug: From what I can tell, the slab is more of a spacer. The electrolytic caps on the end of the ESC are a little higher than the tops of the FETs, so the slab takes up some of that space. It probably also acts like a heatspreader to some degree as well.

The datasheet for the FETs can be found here. In this post, I made some observations about these FETs and why they may not like 6s. make sure to look at the derating charts...