Trouble with battery drain and possible dead lithium

[nitro28]

I recently purchased a 2009 club car precedent that had a complete lithium upgrade. I am completely new to this and have already run into a number of issues with this system so hoping all of you can offer some advice.
The system is:
Alltrax XCT 500
A 7 pack of Nissan Leaf cells
200 AMP HD Solenoid
A BMS which looks like the one I see on Tech direct and is controlled with an app called Xiaoxiang BMS
Stock motor
Under cart leds
LED Headlights and tailights
A 58v charger

The first day I had the cart my 14 year old son ran the cart too long and it hit the 44v cutoff. It then wouldn't charge unless I lowered a couple of setting in the app. Then this week he ran it again fairly low again even though I had given him the ability to watch it on his app. I also ordered a voltmeter readout for the cart so he can watch it in front of him.

Now the big problem. While I was out of town he ran it all the way down and of course the charger won't kick in when that happens. The cart then sat for 2 days and there is something that is drawing the battery down. When I got home last night the 48v pack read 20v. Then this morning it read 13V. My guess is that leaf battery pack is toast, correct?

So, I just want to make this a good reliable long range golf cart so looking for help and suggestions on what I should do. Should I buy a 100+AH lithium battery replacement since the battery I had in there was only around 50-60AH? If I do that do I need to switch up any of the equipment? Is there a BMS that will better protect the new battery from my kids messing it up? Maybe a limp mode or something? And any idea what would cause that battery drain (BMS maybe). I did have an issue also this weekend where the BMS would not show up on my app. its bluetooth module was not seeming to light up at all. I unhooked it all and rehooked it up and suddenly it worked. Seems suspect to me. Thanks in advance for any advice. I don't mind spending a few thousand to make this all work well.

[WalterM6]

Your batteries are shot. Do not try to charge them. Remove them from the cart. Read the post about Lithium battery exploding. https://www.buggiesgonewild.com/showthread.php?t=150460

[nitro28]

Thanks I assumed that would be the case. Honestly they didn't have enough range for our needs anyway so it is what it is. So where do I go from here?

[Volt_Ampere]

I would go with something at least double the amp hour rating of the 7 module you have. I would also go with a BMS that will not let you run it down far enough to damage the cells. It should have a real LVC that stops current consumption completely. These cells will last a long time IF you use them properly. They will die quickly if you over / under charge them.

[nitro28]

Volt,
any brand suggestions on a big battery and bms? I am completely new to all of this. I definitely want something with a lot more range and with a 14 year old kid, I need to have a kid proof bms too if they make one. Not sure what would be drawing the battery down that fast when its just sitting there too??

[nitro28]

This BMS has a cut off in it, but when it hits that cutoff it then won't allow you to charge it which is dumb in my opinion. Then what took down the cells in this case is the cart hitting that cut off then sitting in the driveway for a couple days and losing voltage fast to some sort of parasitic draw.

[Bama Brad]

You have 2 questions:
If you want to replace with Lithium, you need as high AH as you can afford. Here is a good thread for drop in comparisons:
https://www.buggiesgonewild.com/showthread.php?t=173142
Also, read up in the "All Things Lithium" section.

Parasitic draw can only be determined by tracing/testing wires. Is there a voltage reducer being used for everything 12 volts? I would start there.

[Volt_Ampere]

I do not have any experience with "drop in" systems. My two carts use Leaf modules - but they are getting hard to find in good condition. I don't use the 7 module packs - just not enough range for me. A decent BMS should still allow you to recharge even after hitting the LV cutoff! Ideally, you should set the LV cutoff to where the pack is plenty safe from damage. There is very little capacity left at that point anyway. I recharge mine when SOC gets to about 20% capacity. Usually higher than that because I need enough range to play a round of golf. I can get four rounds out of my old Leaf pack. (14 modules)

[nitro28]

Thanks Volt. I thought it was weird that it makes me change settings to just charge it after hitting the low cut off. In this case it cost me the whole battery so that is definitely something I will be looking at. I see several batteries from places like bigbattery that seem to have a built in bms in the battery. Wondering if those would work well with my kids or if I need something more advanced.

[nitro28]

Originally Posted by Bama Brad

You have 2 questions:
If you want to replace with Lithium, you need as high AH as you can afford. Here is a good thread for drop in comparisons:

Also, read up in the "All Things Lithium" section.

Parasitic draw can only be determined by tracing/testing wires. Is there a voltage reducer being used for everything 12 volts? I would start there.

I do have a 12v reducer. I think its the middle picture above. It should just be the lights and under car led lights hooked to it as far as I can see. I will do some checking.