I like that approach since the DRV seems to be the Achille’s heel on these things. But is that a possibility for the relatively near future?
1 Like
That would call for a redesign…but would be worth it in the end. Tradeoffs would include probably a larger board size or having to go double-sided to compensate. This won’t make it to the CFOC2 v1.0 release and would be more appropriate for a gen 3. My plate is full right now so I wouldn’t expect it this year.
9 Likes
You guys see this DRV less vesc6 based controller? Worrier6
Seems like a similar philosophy, although low cost and consistent stock are not the main priorities for this one. The main downside is it requires a modded firmware.
2 Likes
It looks like that’ll be retail only - right? Not open-source?
I don’t have much experience in power electronics (low power MC’s and FPGA’s mostly).
What can you tell about IRFB7534PBF as an analog to NCEP60T20?
Or maybe you can recommend some other MOSFET, one that can be bought outside of China.
Looking at documentation - IRFB7534PBF is a good analog, correct me if I wrong.
Its based on VESC, so everything from the schematic to the modified source code (and compiled code?) is available for download. You’d be hearing from Frank if it was any other way.
1 Like
The closest replacement I’ve found is the TI CSD18536. In theory it should even outperform the NCEP60T20 by a little bit. I believe Shaman used the TI part in some testing.
He says it’s not open-source.
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?
1 Like
@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.
4 Likes
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.
1 Like
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.
4 Likes
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.
2 Likes