So bike isn't exaclty going to sustain 2000 watts.. but worst case internal pack is on its own and has to put out 50 amps... though I don't think that's actually possible so lets just go with 40 amps max...
Safely connect 2 or more batteries with different voltages to a single supply also protects batteries from dead shorts or other circuit related issues
uavmapping.co.uk
Uses:
https://www.onsemi.com/products/discrete-power-modules/mosfets/fdb3632
9mOhm resistance, ballpark 40**2*0.009 = 14 watts heat. It would actually be higher than this.. even with lot of heatsink its in a small enclosed space above a warm motor. Just seems unrealistic to make work without limiting motor power. At 15-20 amps seems realistic?
Then there are these:
https://www.aliexpress.com/item/4000299576209.html - Quad
https://www.aliexpress.com/item/4000971652693.html - Double
https://www.aliexpress.com/item/4000971604695.html - Single
Uses:
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d4624a75e5f1014ac94680661aff
1.5 mOhm resistance, ballpark 40**2*0.0015= 2.4 watts heat, and that's with just 1 mosfet. With two they each do 20**2*0.0015=0.6watts, 1.2 watts for board. WIth 4 they each do 10**2*0.0015=0.15 watts, 0.6watts for board.
Interestingly the double and quad the board size is the same so it kinda makes sense to pay a few bucks extra for the quad to halve total heat. Both the double and quad can get just board or potted with heatsink.. doesn't seem like its same heatsink for both though, and not sure what either of their dimentions are, both seem big. And with how little heat they make all that heatsink is a waste.. and probably won't even fit.
The single can come with a cover, I guess its like a piece of plastic or something? -- They say black or yellow, so yeah not sounding like its going to help with heat at all, only hurt if anything.
The single somes in a few versions, I assume the 100v300a one uses 105N10N5 mosfet, in pictures I see it. Also in description mentions
[email protected] for an hour it reaches 36C and
[email protected] 41C... doesn't say ambient though, lol.
Realistically seems like single with a little heatsink would be good enough, especially for external battery that has better airflow. For internal could get single w/heatsink or be more paranoid and get quad with little to no heatsinking? Its bigger than single but still just 50x55x20mm, if it fit seems like decent option.
(edit)
Actually another version of single with 80v version:
https://www.aliexpress.com/item/4000299511206.html
With:
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d4624a75e5f1014aca59127a1eb9
Only 1.2mOhm resistance. And this aliexpress link can get with heatsinks for a couple bucks extra.
Suggestion is with shell (which I guess is not heatsink just some piece of plastic or something) 15A, without shell 20A, with dual heatsink 30A, all continuous. So yeah that seems reasonable to me. They show 25A with dual heatsink stablizing at 45.5C in open air. In frame yeah on a hot day.. yeah starting to get warm.. could put beefier heatsink to give some more mass to handle longer bursts of 40A. Or just go for the quad board.
I really have zero need for 2nd battery.. but I might get a quad board and 2 singles with heatsinks and mess around with it for fun.