I’ve been running these bms for years without trouble.
I can’t think of what could burn shunt resistors.
Resistors and transistor switches connect across each cell to discharge high cells. Only high voltage across those two can burn them.
If I had to guess, it would be high resistance power connections on those two cells.
I couldn’t tell you, that’s above my pay grade! What is a high resistance power connection?
I don’t expect you to pay for something that I may have done or we can’t explain. I’ll gladly pay for another. I have put 3 electric skateboards together, two with Lipo and BMS, they always worked fine, when I built a board with an 18650 pack it loved to smoke bms’s for some reason. Did you happen to find one?
Yes, I have both 24s and 32s.
The cell to cell connections are the one I refer to.
If one was loose or not making good connection, the entire pack voltage would appear across the balance leads.
In theory a bad cell would do the same. Before changing anything, measure voltage across those two cells under load. If you can’t find the problem, will likely recur.
That can’t be good. Is that a fuse or switch?
Not good. 
That’s the switch. Not going to say that was a rookie mistake (it never occurred to me that it could cause a problem) but could that have blown it?
Send me another 28s BMS please, I’ll paypal you, just let me know how much.
Worse case the switch was open, full load would pass through balance leads.
I’ll see what you paid last time. You could save money getting one from China, but it takes a few weeks.
You don’t need the LCD. That saves $25.
Switch was open, I closed it and the resistors burned. Lesson learned.
Is a switch then even needed? Where would you place it?
If you have one, I’ll take yours, unless you need it for something. I’m itching to get this buttoned up now.
A switch is nice. Either end is fine B+ or B-. Besure everything is solid between cells.
Say $150 main board only.
I’ll send it over to you today. Now that I’m thoroughly paranoid, when plugging the white connectors back into the board, should the car be switched off? Any order to put them in?
Sorry if this is rudimentary!
I took the car for a quick spin last night and it seemed very jerky on acceleration and top speed was about 30. Do I need to adjust anything on the controller?
They do get somewhat jerky with high voltage. No one has taken the time to figure it out. I padded the throttle pot to make it less sensitive on the bottom, one time. But mainly I just learn to drive it.
Ask Grant about it.
So far it hasn’t been bad enough that it’s been fixed. You can always use less voltage in a pinch.
Plug in low end plug first. The high one powers the board. Ideally there would be a switch on the last wire that powers bms. No matter car on or off.
would you mind if I gave you a call real quick?
5078944754
Thats exactly what I was going on. I lowered #7 to 55 and got to about 35mph…still not what I was hoping for. I took out the motor and Im going to give it a quick tune up. Im traveling for the next few days so Ill report back later in the week.
Yes, it comes set for 32 x 4.2v cells.
See if there is a place to change default to lithium iron.
Else change each setting to what you want.
Most will be labeled good enough to see.
I’m looking at settings side ways until I get on my pc.
First one is hv alarm. 3.7 or so?
Low alarm 2.5?
High protect turns charge off. 3.55 or so.
Ask if you don’t know what they do.
Total high volts is the highest you want to see. 3.55x28?
No right or wrong.
Thanks Dave, I think I’m getting it. Should MOS charge be on?
I think that’s a different screen. To turn on charger manually.
Still looking for settings list.
I bet bt still works on your old one. It only needs 24v on the last pin to boot up.