Do you have a VX2 remote? Or any remote connection via uart? That seems to interfere with the app
I do have the VX2 and itâs quite possible it was connected. I read somewhere that bluetooth devices interfere with the app but itâs entire possible I had the remote on when it wasnât working and off when it did and didnât realize the remote would interfere with that as I believe itâs 2.4Ghz connection. The app does transition from motor config to remote config so itâs reasonable to surmise that the remote could be on for that process. Iâll check tonight.
They must have made the batteries with the thinnest of nickel strips as they appear to tear easily. This is an easy fix.
âBattery regen, set that according to the brake performance you desire.â
No, please donât do this! Apologies if this seems aggressive or Iâm just replying to a typo but you should set the âMotor Current Max Brakeâ to whatever you want/need for braking performance, but do not set the battery regen current above the rated charge current for your battery.
The simplified version is motor currents set performance in accelerating and braking, as long as you donât exceed the motor current ratings youâre fine. Battery currents set battery safety limits. Do not exceed battery safety limits unless you know what youâre doing.
Rule of thumb: high quality 18650/20700/21700 cells last best when charged at 1A, and can usually accept a fast charge rate of up to 3-4A per cell. Check your specific cells if possible. If itâs a 3P pack, then 3 cells are charging in parallel so itâs 12A max before youâre almost definitely exceeding the specs. This 12A also applied to regen, I guess if the manufacturer of the pack (boundmotor) is happy to stand over 20A charge current thatâs ok but it is not what the cells (think samsung, LG) are made for and not a good idea
Yeah that may explain the 12A regen settings I saw on many 3P setups when searching for answers. Boundmotor has been really good thus far at providing information so Iâll leave the 20A regen as it is for now.
If youâre saying a 3P charging at max 4A per cell means a packing charging max of 12A then a 4P would be 16A, if Iâm understanding this correctly. So absent battery specs this is the type of rule of thumb thinking I need in order to derive settings with those 3 cell types.
Yeah exactly, 16A for 4P is a decent rule of thumb. If youâre curious about learning more my main sources are datasheets for
- LG 18650 HE2 (the cells I use because they have a high discharge rate and were available cheap because theyâre slightly older tech and not super high capacity)
- Samsung 21700 30T (relatively common, relatively modern 21700 cells)
Datasheets for individual components can be dense as hell because theyâre generally only meant to be read by engineers focused on a specific project, but the first page of text and first table are usually interesting. The standard charge and fast charge currents are what weâre interested in
Oh and one last thing: a big part of selecting components when designing a product is validating it for your specific use cases, because the manufacturerâs specs can never cover every case. If boundmotor have put effort into validating these cells for use in a 20A recharge pack then itâs all good, they might have evidence to agree with the person above who said that because braking is a short burst you can exceed the charge current. But honestly thereâs a reason the main charge current in these datasheets is around ~1A and the 4A is close to a maximum. These cells already only last 500-1000ish cycles, and I donât think thereâs any eskate company whoâs got an engineering team that can overrule Samsung