Ok great. I’ve done some diagnostic stuff on the bike that doesn’t work but my results were inconclusive, I’ve replaced just about everything except the hub motor so I’m hoping that’s the issue, these bikes are definitely money pits for me but I really enjoy riding them.For the bike you're stumped on, I'd first recommend making a thread here with everything you already know about it, and anything that's been tried and results of that. Then we can work out what hasn't been tried, and what might be tested to figure out what's wrong.
For the hot controller issue, if the controller gets that hot, how hot does the motor get? If the motor doesn't get hot when the controller does, it's probably just that the controller gets no airflow. Best way to fix that is to move the controller where it can get air, or force airflow over it. Scoops aren't needed, since you'd have to go pretty fast for anything reasonably sized to scoop up much air, just intake holes at the appropriate point to cause airflow over or thru the controller then to the fan pulling the air. If you can take the end caps off the controller (depending on it's design) you'll get a lot better cooling than just airflow over the outside, especially since most controllers have at least two heat-transfer junctions between the FETs and cooling airflow (and those are not always made well enough for very good transfers).
If the motor gets hot too, does it get that hot even with minimal load, or only when used hard? If it gets hot even with minimal load, it probably has the wrong phase/hall combination, and that's easy to fix. If it only gets hot when used hard, it's probably just not enough controller and motor for the job; increasing cooling can help with that in some cases.
With the new controller, it's probably setup for high motor phase amps, which will give it a lot more pull (but will work the battery harder in doing so, making it more likely to trip the BMS either more often or sooner, assuming the BMS is tripping from overcurrent).
If you want you can order a cheap wattmeter, something like this one:
(there are better ones that do more stuff, like the Cycle Analyst, but cost is far greater if you don't need the extra stuff)
and measure the actual power / current used in various situations, and see how much voltage sag your battery has under that kind of load. See this thread
for an example of a similar situation; in his case it was a fuse blowing rather than BMS shutdown, because his bike was built with a too-small battery pack as well that couldn't handle the controller used, so they used the fuse to protect the battery from overload by the controller. In his case limiting the controller via programming is a first-line option, then probably getting a new battery that can handle the power required by the controller's full capabilities (as measured by the wattmeter), or some similar end-result, if it doesn't do the necessary job as-is.
SOLVED: Blown Fuse on New Stealth Bomber Clone
I just received my Stealth Bomber Clone from an outfit in China called Coolfly Bikes. 8000W QSMotor SVMC72V100(M) Sabvoton sinewave controller 72V 41.6AH(China Battery) On the trial run, going about 35MPH / 56 KPH, after riding for about 20 minutes.. all power died to the bike, display went...endless-sphere.com
For coming down here to directly work on anything, my first real free time will be coming up near the end of April, which with luck will mostly be used to do some major stuff to my SB Cruiser trike, but if plans go as they should I could work on something else like looking at your stuff. Don't know if I can fix anything, but possibly find out what a problem might be. But it would have to be something where you bring it down, we look at it, and you take it back with you, rather than leaving it here to work on.
I am typically off Sundays (which I usually have to spend recovering from the rest of the week) and Mondays, and sometimes have enough energy recovered by Monday to do something for a short time, if you are free to come down here about the middle of a Monday.
I started modifications on the frame last night to get better cooling and plan to bring a laser thermometer and monitor the temps to see if it’s effective. I like the idea if removing the end caps to the controller to increase cooling efficiency, I’ll do that too, thanks
As for the motors temps, I’ll keep an eye on those too, I fried the motor once already by riding the bike up too steep and Rocky of a trail and over heated it ti the point that the glue holding the magnets in the hub motor failed
I should have my 72v bike done this weekend to test. My battery has an in line fuse on the positive cable too so that could be a weak link with the new setup. If it gives me trouble I’ll buy the new battery, I just want to be sure it’s needed before spending the money on a new battery. I’ll post some pics of the frame mod for cooling too
my plan to remedy this is to build a carbon fiber cover for the seat bracket/tail section frame and mount the controller inside of it and then redesign the fan system with a smaller fan, this will free up the space inside the frame I need for the larger 72v 40ah battery with 200a bms… I found a guy on Facebook that is gonna build the custom battery for me.
