When using the METR app to do motor detection &/or tweak settings on the VESC (in my case a Spintend Ubox V2 100V 200A Dual Motor Controller based on VESC)
Can anyone confirm for me if I should be dividing the battery current max in half if I’m using the METR app to change setting in the VESC as opposed to doing it using the VESC app … I’m doing this over Bluetooth with my phone too btw.
Screenshot attached…arrows pointing towards setting I’m wondering if i need to split in half…
oh ya! also I’m asking cuz I got a pre-built I ordered a bajillion years ago that showed up seemingly without having been set up…
it’s a 18s 8p battery pack with Samsung 50 21700 cells… which have a continuous discharge rating of 9.8 amps per cell.
am I correct that the battery pack then should have a continuous discharge rate of 9.8A x 8 =78.4A ?
and if those cells have a charge rating of 2.5 amps would the Max regenerative Amps /charge value be 2.5x8= -20A? …so if setting it up in. VESC app i’d set the main and can fwd regen values to -10A each? or cxn i go higher? this rig weighs over 50lbs and j ride in SF …lotsa hills …i want strongest brakes possible…
Yes, always divide by half and remember to configure both sides of the ESC.
Yup, math is correct.
Theoretically yes, but that is obviously pretty low. Personally I like to set my regen current to half that of the discharge current. (39.2A in your case) Most people seem to abide by that rule, and no one has had anything bad happen from charging their cells faster than the spec sheet says for a few seconds. Just don’t abuse it, it’s more for emergencies.
Personally I wouldn’t have built a pack using capacity cells like that if I cared about strong brakes and good acceleration uphill, but, hey, that’s whatcha got so it is what it is. Values might seem a bit low, but hey, it’s 18s, so multiply by 1.5x when comparing to other people’s setups
Hey thanks man… The regen current has always confused me.
Thank you so so much for verifying my math. Thank you so much for taking the time it was really very very helpful got me peace of mind and the ability to tweak settings confidently and the result is a super stoked Rider over here that was able to get his settings dialed in confidently because of your confirmations.
Thought I replied a while back when I initially received your responses & somehow flubbed it. Wanted to make sure I I probably expressed my gratitude.
The rest of this post is extraneous information and experience sharing that I thought might be interesting to some folk fair warning…as this will now be TLDR³ territory.
I really appreciate the information and advice. I’ve got regen set at -45 now and the braking current at -85…my deadband set at 8% with the Hoyt Puck / current w smart reverse …1.5 seconds to full reverse…10% of max erpm … Using the VESC Android app for all configuration changes… have an upgraded to most recent vESC version…i had problems w the new VESC app update.
I have each motor set at 100 amps, absolute Max current set at 160 A
Battery current set to 60 amps for for the primary and secondary Vesc… using the polynomial throttle curve & set the + ramping at 40 and the negative ramping at 20 …the thing jumps pretty well and stops pretty much on a dime now.
It doesn’t blast off the line like my OG Lonestar or blasts up hills as fast but this thing is a Kaly XLR and it weighs like 55 lbs…or more…its a beeeast… Just wish it had some Flex to the deck … it does not flex and I ordered the flexier option… It’s lacking and turning radius but carves pretty well and is a smooth ass ride puts me in a flow state quite a bit and those Wheels have such a huge contact patch I lean into turns and carves with abandoned …there’s a couple spacers on the front trucks stacked on the axle so I recently moved one of the spacers to the outside in between the nut and the bearings from both front wheels and that has made it quite a bit more agile when it comes to turning.
If the deck flexed at all I’d be happier but I’m pretty damn happy… That said anyone has any recommendations for a deck that I could swap all this to that would Flex I’d love to hear suggestions. I’m trying to figure out a way to get confirmation that the board was built on the level 2 flexier option deck and Ernesto said he’d throw a caliper on the level one Flex deck for me I just haven’t followed through on that discussion yet.
