That’s true but even if you did that it would still work, it wouldn’t be the prettiest thing but it would work. Also you could mount all the components on the opposite side and just bolt the FET through the PCB onto the large contact for the drain. In fact that might actually work pretty well and I may do that my self.
I think that’s sort-of what I’ve been saying 
Just finished building it! I thought I’d show everybody here.
I left out the LED. I tested it on a 15 volt power supply and it works. Time to test it on my 10s LiFe batteries.
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Works perfectly on 33 volts too
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That’s so cool that you actually built the design! Thank you it means a lot! That’s great to hear that its working well, did you use the same IRFB7530 MOSFET or did you use another type? Also I would recommend that you maybe shrink wrap the entire thing or wrap it in electrical tape, if you haven’t already done that lol.
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Of course! I used the IRLB3034 cause it was cheapest and my batteries will stay under 40 volts. I definitely plan on insulating it with something. Wish I had some large clear heat shrink.
Yeah the 3034 is what I’m using in my board and it seems to work very well. Did you buy the 3034 on EBay from some cheap seller or did you buy them from a trusted retailer like Mouser? I’m just wondering because you might wanna be careful running them near there limit if there cheaper non legit versions. I’m using some cheap ones off of eBay though they work fine for me and don’t get warm whatsoever at 6S ~15A cointinous.
I got the ones off eBay that you linked in your first post, it’s been working fine so far just testing on my desk with no load. I guess I’ll find out how it works with load once I complete my board haha.
I’ll test these on a 6S when they come in:
Will be using these on my own stuff though: http://au.rs-online.com/web/p/products/8208833/?cm_mmc=AU-PPC--google--3_AU_EN_M_SEMIS_Broad-_-international_rectifier%7Cmosfet_transistors&mkwid=sFxbMWOKY_dc%7Cpcrid%7C82233297603%7Cpkw%7C%2Birfb7530pbf%7Cpmt%7Cb%7Cprd%7C
When I etch my board I’ll post pics. Thanks for sharing this with us.
Can anyone with more electronics knowledge answer this question?
Suppose this switch is off and I am kicking my board. I’m assuming the Vesc will be on because it is being powered from the motor spinning. If I send a brake command to the vesc will the batteries charge? (because mosfets do not block current going backwards)
Well first off I heard some people talking about almost exactly this in another thread, I’m not sure where but ill try to find out. Though eventually they decided that pushing the board along with it being off was a very bad idea, and they are very right. If the switch is off then it won’t allow current to flow either direction which means you’ll have an electron buildup which could, and will, lead to either killing a your VESC MOSFET or other components connected to the circuit. And I don’t even think peddling would supply enough current to keep the VESC on. But if it did and it tried letting current flow to the batteries, obviously the MOSFET switch but be in between and would then either kill the fet or the VESC. @ndwallick
Hey Astro! The ones you linked on EBay I’m sure will work, but they won’t be as good or as trustworthy as legitimate versions from a trusted retailer like the other MOSFET you linked. Also you can get the exact same IRFB7530PBF on Mouser for only $3.33 so there a couple $$$ cheaper. And Mouser is definitely a legitimate vendor.
Do they ship free to AUS? (edit) Just saw ‘Free shipping for orders over $60’ not sure if thats int. though.
Have no clue you might wanna just check yourself by checking out and getting far enough to see shipping rates. I ordered 10 IRFB7530 on Mouser for $2.83 A piece and they seem to be of good quality and shipping was right around $5 but that was in the US.
Thanks, might get my hands on both and compare them for the Aussie users.
VladPomogaev was saying that I should also have the MOSFET on the opposite side of the board like most PCB’s are and have a bolt go through the board and that was definitely the right idea. Anyways I redesigned a small part of the schematic to accommodate the MOSFET being mirrored on the opposite side of the copper traces. So if you plan on doing that please use this design instead.
And you can download the .sch and .brd HERE
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You mentioned wanting some large heat shrink and I found a bunch of different sizes on Aliexpess, I just ordered THIS for $2.20 and ill see how it works once it gets here. HERE is a search that brings up a ton of different sizes of heat shrink on AliExpres. Just make sure to put how large you want it in mm.
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Wow that is CHEAP. Ali’s a good place to get stuff from if you don’t mind waiting a couple weeks. I got two pairs of bushings for $2 as well.
I finally finished making the circuit and it turned out ok! I tested it at 15V and it works fine though I’m going to be testing it at 24V soon. I’m aware that my soldering skills are complete crap, but hey it works lol. For the XT60 leads I used some awesome high strand super flexible 12 AWG wire and the mosfet is the IRFB7530PbF for a 12S build. I still have to shrink wrap the entire thing to give it some protection but I will do that when it arrives.
P.S. I got my 12AWG Wire off of Amazon, but I found some on Aliexpress for $4 a meter, which is pretty good in my opion if you don’t mind waiting a month. LINK
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Just don’t order cheap fets or caps from Aliexpress