My boards been out of action for the last couple weeks while I was waiting on some extra batteries to arrive and get my repaired VESC back from @chaka. I’ve had the board back together for a day now and for the most part it’s been running perfectly.
However when I went to ride up a fairly long and steep hill tonight I got about half way up and I slowly began to lose power until it got to the point where the board was barely moving. I got off for a couple seconds then got back on and started riding again and it seemed to have full power back but about another 10 - 20m up the hill and the same thing started happening. This basically happened another 3 or 4 times till I got to the top of the hill.
I’ve ridden up this hill many times in the past without any issues and the battery was still at 65% at the top of the hill so it shouldn’t have anything to do with low voltage cutoff kicking in. Since the board was running last (when I didn’t have any issues with this hill) I’ve upgraded the battery from a 10s3p to 10s4p pack, replaced my enertion remote with a GT2B and had my VESC repaired. While @chaka had my VESC he flashed it with 2.18 firmware (from the original 2.16) and it’s now running in BLDC mode (was running in FOC before the repair). Other than that, I’m using the same firmware settings as before.
Board specs:
10s4p space cell
Single Enertion 6374 motor
Ollin VESC
GT2B Remote
thats 100% the thing that happened to me - longer 5-7% hill and Ill eventually become slower and slower until Im barely getting forward anymore. Im about 90% sure that its the vesc overheating soft off that starts at 80°C and switches off the vesc at 100°C (only 90% because Ive never actually did live monitoring to convince myself, but so many indicators speak for a heat issue, that I feel I didnt have to make sure).
and like cookies said: in a direct comparison of bldc and foc, foc came out on top. I can reliably ride up that hill in foc with full throttle without powering down at all while I reliably get power reduction in bldc. thats with the exactly same hardware - just changed bldc for foc.
did that run up the hill several times on different days, since its part of my commute. every time the same result!
@chaka
I ran motor detection and ran settings, will post a few screenshots later today when I get some free time at work.
@PB1
It’s the middle of winter here so ambient temperature will be cooler than before if anything.
I don’t think changing from 10s3p to 10s4p should have any effect in this regard as the VESC will still only pull as much current as it needs.
I’ve been having the same issues with my board although I just finished building it. Happens after I ride for awhile and try to go up a hill. Doesn’t necessarily have to be that steep of a hill or that long, the board just has to be running for a bit. With the board cold, I can run up a 2-3% grade for half mile with no issues. Just added some heatsinks to my VESC last night. Haven’t tested it yet, but will see how it works.
Drop the motor max down to 40-50 amps if you want to climb hills. It may still overheat the vesc because 63’s motors will still pull a large amount of wattage but it should help. Best to go dual if you want a cooler running board. 80 amp max will work on flats and short hills in a single 63mm drive but you may need to bump your overheat protection up a few degrees and use a heat sink and fan.
What other noticeable effects might I expect from lowering the motor max? Lower top speed?
Definitely planning to upgrade to dual motors, just not sure whether to wait for VESC 6 or not as well as whether to go with dual 63mm vs dual 50mm motors…
@chaka if I’m having issues running a single 6374 motor up this hill, how do you expect a pair of your 5065 motors would handle it in comparison?
The hill is 0.7miles long with around a 310 foot increase in altitude
are you the same guy who bypassed the BMS for discharging?
do you know what the BMS is rated to in your SPACE Cell?
it’s either the 30A one or the 50A one.
You need to set the motor max lower, 80a is way too high. 60A MAX for that. Maybe lower.
Battery MAX of 40A is also too high if your BMS has a 30A BMS.
It might also be worth checking the voltage MIN - MAX, maybe you are hitting the voltage soft cut.
worst case scenario bypass the BMS and increase your Battery Max current to number closer to the Motor MAX. The VESC will appreciate that especially at lower RPM.
In the end I didn’t bypass the BMS for discharging, managed to get that issue resolved.
From one of my previous threads, you’ve told me that my BMS is rated for 50A continuous, because of this and the fact that my space cell came with a 40A fuse, I’ve set the battery max to 40A.
I based most of my VESC settings off the information you’ve provided here for the space cell which states that the motor max should be set at 80A:
I’ll lower the motor max for now and see how that affects things