Because my second BMS order from LitechPower again is missing the ESwitch, althought the description said it should be integrated, i was asking myself how far is it necessary as an antispark replacement. Based on the fact an vesc, or more specific the focer has an onboard switch, do i need one?
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@Josh and I used IRFB7534PBF on our FOCers, Has been working well!
The CSD18536 mentioned from @SRFirefox does look slightly better with the lower Rds it should heat up a little less.
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Like Bryce says the IRFB7534PBF has been working for us.
The CSD18536 is a lower loss FET than the IRFB7534PBF; both Rdson and switching losses will be lower so it won’t heat up as much. But it’s over twice as expensive when I checked at Mouser.com $4.66 vs 1.92 per FET.
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Careful with the CSD MOSFETs from TI. Yes they have lower Rds(on) but their gate voltage threshold is really low. Meaning that they are more easily accidentally turned on by noise. It’s a trade off.
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I’ve look at the pin out ports of the Cheap Focer, but I’m a little confused about charging. From what I can tell, most people have custom batteries. Does the Cheap Fover require a separate BMS device? If so, how do you wire it? How would someone like my self wire a battery pulled from a hoverboard? I believe hoverboards have charing built into their mainboards.
I’ll direct you to battery building 101: Battery Basics for Beginners [Serious]
and once you finish that, 201: The battery builders club
As a quick note:
If you take the battery out of your device and see just 2 or 4 (thick) wires, that’ll just be charge (and/or) discharge, and banance is handled by the pack (or not at all in the ones prone to fire…)
If you see 2(thick)+{9-11}(thin) wires, that’ll mean balance is handled externally to the battery (by the motherboard as you mentioned, then you’ll be able to buy a BMS to plug into the 9-11 pin connector).
And a heads up: you’ll also get a lot of push to dump the hoverboard battery entirely since it’s probably pretty light duty and not likely to be terribly great in either discharge or capacity…
Thanks for the tips/info/links. That’s a bummer. I have 2 x 36.5v li-ion batteries. Pretty sure charing is done through the mainboard, so built in BMS.
No built in BMS*
I’m about to toss two of my 0.9 into an existing build and try em out, whats new in v1.0?
I just ordered a bunch of 1.0’s. Only issue I had was that the LCSC BOM did not include the USB port so I forgot to order them.
I’ll let you know how it goes soldering the driver’s by hand.
I had put a V1.0 order together, but I posted a question here before pulling the trigger. Shaman suggested waiting for another update, so that’s what I’m doing.
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Hey,
I want to use the controller with a 13s li-ion battery (54v charged). I understand that some people have done this, but its outside of the specification and thus probably not reliable.
My question is: which components limit the voltage tolarance? I.e. which componets would need to be replaced by slightly more tolerant ones to raise the voltage tolerance from 12s safe to 13s safe?
There is no drop in replacement. Afaik what happens on high voltages is that the DRV chip fries itself. If you want something that’s actually 13S safe, you need a 75V vesc. If you are not using electrical brake, or you are using a very high powered battery (like at least 13S3P P42A or maybe even bigger, you absolutely need a high current pack, that doesn’t sag a lot) than you might get away with it.
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Just got my 2 boards from JLCPCB last week. Yesterday I spent a couple of hours soldering and resoldering those blasted DRV chips. In the end I had to go out and buy some better flux, apparently the one I had from Aliexpress was crap (who would have thought). The instructions on Github were spot on, I started the boards on 11V current limited to 100mA and found one that was drawing the full 100mA and the inductor was buzzing (coil while but a lower frequency than seemed healthy to me), turns out the ground pad wasn’t soldered on properly. Took it off with hot air, resoldered it properly and it started working as expected.
Glad to report both boards flashed and booted without incident! Thank you Shaman for all the work you’ve done on this project. I’ve been using the original Cheap FOCer in my electric scooter for about a year and some, never had a single problem, doing 700w on 10s all day long.
Time to put these bad boys to work as well.
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Cool to see a Cheap FOCer veteran! I’m glad you managed to get everything working!.
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Hey. I have a unity that motors turned fine 6374 battle hardened flipsky. Did a motor test showing a friend how ubset em up amd then right motor stopped turing normal. Took out halls. Works fine. Plug em back in same prob. Silicone is on back of jst connectors so no loose wires. Super confused.
If I were going to hazard a guess, I’d say you’ve got one or more bad Hall sensors, or bad connections to them. Do you have a scope to look at them on with the motor running?
Ummm idk. Is that rhe magnifying glass at.the electronic station??. The wires dont seem broken. Inoulled sleeve back. But idk the difference bewteen hall sensors and jst connectors. Like if i swap out connectors wont it just still not work?.
