If that battery has a BMS controlling the discharge and charge, then setting the charge current too high might trigger the BMS to cutoff, which can burn your ESC. Without knowing what BMS they used it’s hard to give a recommendation – it could be 10A, it could be 20A, it could be the mere 4A they list on the website
Unless someone else chimes in / or you can find someone with the same pack, you might have to open it up to see what BMS they used. Or, hopefully, if the BMS is only wired for the charge port, then you can probably set charge current to half that of discharge. Which might not be safe since we don’t know what cells they used, but usually that’s fine.
Don’t touch this setting, leave it at 100000 or whatever it is by default. If your skateboard goes above that speed, you will not only lose acceleration, but also brakes. Better to adjust max duty cycle lower, if you want to limit speed. But that has nothing to do with what battery you have, so just leave it be for now.
This is very rare for a bms that we use in esk8. Most have separate input for charging so you limitation is the max discharge the bms can handle. The limiting factor most of the time is the charge rate of the cells are
It’s rare when we build the batteries and boards. If you buy a prebuilt board or prebuilt battery pack, it’s actually very common. Sometimes regulations make such things mandatory.
Thanks everyone for the advice. I finally got a chance to open up the pack to take a look at the BMS. it says p10mk05 on it. And the large black wire goes to the vesc and the small one goes to the charging port. The individual battery cells say they are ZN 18650, and I found these by the same name - litechpower.com/product-detail/batterycellZN18650%201800mah.html
Here is a picture of it -
But both of those are LifePo4 cells, which don’t operate at the same voltages as Li-Ion do. Did diyeboard just outright scam you?
In any case, looks like that BMS is not discharge bypassed (Since the thick black wire from the ESC goes to the BMS, and not the pack directly) I can’t find any information about that BMS online. In the picture there appears to be a URL and a revision number above the P10MK05 line. What does it say?
Yep, that’s the only thing I could find as well. There is another tiny datasheet before that page though. So depending on the exact model, it might be either 10A or 13A max charge current (yikes! That’s way too low for electric skateboards!)
What kind of board are you building? If it’s something low power, then I guess you could set battery regen to 13A, but if you plan to ride fast on the streets, then it would be best if you bypassed the BMS for discharge (you can search on this forum for a diagram / instructions for how to do it, it’s quite common), and then you could increase battery regen to like 25A probably. (If you have dual drive then split those values in half)
He’s being overly conservative (valuing his battery life more than his own life from not being able to stop on time); Anything below 20A will feel weak when stopping. And he has a total of 16A, which is still more than what you’d have at 13A.
I mean there’s no harm in trying 13A total to get an idea for what it feels like. I’m just predicting in advance that you’ll want more
no idea who advised you that it could be an ESC issue, because it sounds like a motor issue lol
Oh no! Looks like I will have replaced almost every part on the board by the time I’ve ‘fixed’ it then
Ok so If I’ve understood your generous advise correctly I can put in these settings for now (without bypassing the BMS) without any danger to the board (just myself due to lack of braking power).
Battery Cells = 10
Battery Capacity = 10.000 Ah
Battery Current Max = 25 A
Battery Current Max Regen = -13A
Right?
Then if (probably when) I feel I need more braking bypass the BMS?
Oh I see, ok I’ll set it to -5A then for the first run to be on the safe side. Thanks so much for your help. I’ll update once things are up and running
