New 22s 82v 90ah+ Gem battery

The BMS ( battery capacity (ah) was at 40
You had me change to 15.
I changed it back today to 40.
Is this what needs to be at 84 ?

That should be 94. I can’t see where to set "remaining capacity. Maybe its automatic. I don’t have one here to play with.

That’s not important. We are trying to see how many wh you car uses.
Was it one mile or two miles.

That reading earlier was between 0-1 mile then 1-2 miles.

I adjusted the battery capacity to 84
Went for a ride 8 miles.

Here’s the info with 10 miles total. 1+1+8 miles. Have been running DL mode.

Trying to get home.
Wrench with code 41 is coming up. 4-5 times already. Let cool down. Goes 1/2 mile over heats again.

Error 41 is a controller overheat error - something is making the controller work really hard.

Running harder and faster now. It will only be worse.
We need to get that wh per mile info.

If the 10 miles went from 59ah to 38ah then 184 wh per mile. That’s good.
about 88v average. 59 - 38 * 88volts / 10 hours.

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Start and end
9 mile trip

Good, about the same. 190 wh per mile.
Driving like that theoretical range is 7600/190=40 miles
That is running from 4.2v to 3v which is ok once in a while, but not all the time for long life.
It looks like you are using about twice the power in over speed.

I jacked up front in again. They do spin with out binding up on the rotor. They don’t spin that free because the front drive axle is connected. Rotors have no marks on them and pads have room between caliper and rotors. I have pushed this thing a mile the other day and I didn’t feel it was a struggle or binding up. I did get the brakes lines and drums done when I bought it a couple years ago.

Back to square one with the over heating controller.
Please give any input on should I replace/rebuild or what. Don’t won’t to keep sitting on the side of road. I did hear someone say about a fan. Seems like the controller with the thick black plastic cover over it doesn’t have a great chance to cool itself.

Two batteries are complete and ready to ship.

Inwo, what would the cost for a battery plus charger cost?

Big T- I don’t know why your overheating problem decided to show up after a battery swap, but have you removed/inspected your controller for whatever reason?

Did you notice any goop between the bottom of the controller and the mounting plate? Or maybe a previous tech with a hint of OCD may have wiped it off with good intent.

There are a couple of threads in the archives that talk about some cars needing thermal compound in there as it uses the steel plate as a heat sink.

I think I saw you may have been pointed to a conversation about a factory finned heat sink that could be ordered(back in the day) for those running around in warmer climates.

There have been a few here that replicated these finned heat sinks and even installed fans to get air moving under the controller.

what is your tire pressure? low tire pressure will cause it. inflate to 35psi

The bottom of my controller is squeaky clean. I never saw any thing under controller. No thermal compound.
It was over heating up (code 41) with the old batteries too.

Oh boy !! Tire pressure is 10lb.

Here’s my cart set up.

A must have for heat management.
Also clean and lube 23p plug as per GE.

It was over heating up (code 41) with the old batteries too.

Ah, It seems we may be narrowing it down then.

I seem to remember another related thread that mentioned that too many -41 errors will eventually kill a controller. - Just something to think about.

Depending on where you are right now in your project you might want to do something about this quite soon.

  • see what you can find for thermal paste and spread some between your controller and frame plate.
  • since you are next level hotrod you might upgrade to some sort of heat sink under there. Maybe even install a fan.

For inspiration I submit a link to a thread that started back in '17. Reading through it, the concept seems to have had some legs and a possible solution to your problem.

I had a vision! No, I didn’t hit my head on a toilet, and no, it isn’t a flux capacitor.

Make a sandwich.
If you cut a few lengths of 1 in square aluminum tubing (the length of your controller) and clamped them between the controller and shelf plate with a bit of mayo (thermal paste) in between the controller and tubing.

I bet that would cool better than just mounting to the plate.

That works, but a real finned heatsink is cheap. @grantwest found a place that sells one off custom sized.