Extreme Team (ET) BMS

[Beerdude77]

Background, I had to send my controller to Navitas to get warranty work so I decided to finally replace the BMS in my ET 72v 150ah pack that they sent me earlier this year when my cart was shutting off due to low temps even in the low 60's high 50's. I fully charged the pack before doing this swap so I was getting voltage readings on my meter around 80. I swapped out the BMS and now I am only getting a reading of 50 volts. I contacted the owner of ET and he asked if I had hooked the battery back up to the charger yet. I said no since the battery pack is not back into the cart yet and the controller wont be back in for at least a couple weeks. He never responded after that but it is a holiday weekend.

1)Would connecting the pack to the charger "reset" the BMS to read the pack as full?

2) I am unable to connect to the Daly app unless I can figure out a way to create a load on the battery to kick the bluetooth app to turn on. Is there a way to do this with the battery pack not in the cart? Someone suggested wiring it to an external on/off switch but I would have to order that on Amazon and hoped there may be another way with something I may have lying around the house.

Thanks in advance

[Beerdude77]

In case this helps anyone. After replacing the BMS and installing the new controller and hooking everything up the pack did in fact measure correct voltage at the terminals. That said the BMS read the pack as only 50-60% full so I plugged in the charger (even though the pack was fully charged before removing the old controller and BMS). Well the old BMS had to be reprogrammed to know what fully charged was. Thankfully I was alerted to this before over charging my battery pack and potentially causing a fire

[Beerdude77]

Originally Posted by Beerdude77

In case this helps anyone. After replacing the BMS and installing the new controller and hooking everything up the pack did in fact measure correct voltage at the terminals. That said the BMS read the pack as only 50-60% full so I plugged in the charger (even though the pack was fully charged before removing the old controller and BMS). Well the old BMS had to be reprogrammed to know what fully charged was. Thankfully I was alerted to this before over charging my battery pack and potentially causing a fire

That should say the new BMS had to be calibrated/programmed to the battery. None of this was provided as instructions when the new BMS was shipped to me. Personally I am not a fan of ET way of dealing with this and when/if the battery fails I will likeiy swap over to Eco Battery. While they have had their issues at least they seem to be taking care of the customer when they do.

[Pat911]

I think you’re misinformed in regard to full charge detection. It is voltage based, not capacity based. Your BMS would not have continued charging until the battery was 100% full. Your charger should have sensed voltage and current and cut charging once the battery was full. If this didn’t occur you have more problems than a mis-calibrated BMS, like charging with a non lithium charger or charge voltage being too high. The BMS should have self calibrated to 100% once a preset voltage threshold was reached, but even if it didn’t, it would not have affected charging.

Cheers
Pat.

[Beerdude77]

I did not realized the charger was capable of doing that, thanks. I got nervous when the BMS app said it was only 60% full and the voltage was approaching full voltage and thought it would've over charged it. Really what it all boils down to though is Extreme Team should've sent some sort of instructions for swapping out the BMS and explained what steps needed to be done afterwards. That said the cart is running good now.