LiFePo4 Troubleshooting

[weekster]

I've been running the Extreme Team Evolution/Endurance Series LiFePo4 48v 100AH Battery Pack in my 2002 Club Car DS since March. I've had a few issues and would appreciate any thoughts on troubleshooting them.

1. Although I suspect this isn’t a battery issue, on a couple of occasions after fully charging, I have put the cart into reverse to back out of my garage. The motor engages but when I let off the pedal and then attempt to go again, the solenoid clicks but the motor doesn't engage. This has happened a couple of times and each time, if I let it sit for 10-15 minutes, it runs fine.

2. The 12V connections aren't working (putting out < 1V). They worked fine for a while then one of my kids must have played with the lights and left them on. The cart ran completely dead. I recharged and it ran fine but the 12V connection no longer works.

A couple of days ago, I had been riding for a couple of hours while working on our ranch. I went through a steep muddy crossing when I accelerated to climb out, all the power on the cart went out. Both the gauge on the battery and the external one just went blank. I loaded it up and brought it home and put it on the charger and almost immediately, it showed an 87% charge and now runs fine.

Thanks in advance for any ideas.

[Pat911]

Hi Weekster,

1. Could be temperature related. More investigation is required.

2. Looks like either your 48v to 12v reducer has failed or may have a blown fuse if one is fitted. Check the fuses first and replace if necessary.

3. Your BMS tripped out on high current pulling up the steep hill. Connecting it to the charger reset it. This is normal operation although it would be nice for it to reset without having to tow it home and apply power.

[Bama Brad]

Could he not have disconnected the positive for a little while and reconnected for it to run? Would that have reset the BMS? I also have lithium and want to know if this happens to me out in the woods.

[DaveTM]

Just curious if your 12V reducer is connected to the "entire pack" or just to one specific battery? Also, let me say I know nothing of the pack that you're running.

I'm asking this as if the 12V reducer is just tapped into one battery and that was ran down to nothing.....I'm wondering if you have a bad cell in the pack?

[WC53]

Some bms you have to jump from B+ to charging point to wake up. Others will reset automatically or have a reset button. They will usually list the procedure. If he is still getting pack voltage, I would doubt there is a bad 3.2v cell

[Pat911]

These ready made packs have everything sealed inside. There’s no easy access to the cells or BMS, therefore, the reducer will be connected to the 48v posts as there is nowhere else to connect it. And if one cell is bad, it will shut down the entire pack. Maybe disconnecting the main battery negative and reconnecting it may have woken it up. Different BMS’s work differently.

Cheers
Pat.

[weekster]

Thanks for all of the thoughts. After finally getting hold of the Extreme Team Carts folks, I have learned that the BMS will shut off the battery when the draw is > 350 amps for any significant period of time. I have an Alltrax 500 AMP controller that has adjustments available for Max Motor Amps and Max Battery Amps. Should I reduce one or both of those to try and avoid the BMS shutting down under heavy load?

[Pat911]

Drop max battery amps to 300A and see how you go.

[dawgfan316]

Originally Posted by weekster

Thanks for all of the thoughts. After finally getting hold of the Extreme Team Carts folks, I have learned that the BMS will shut off the battery when the draw is > 350 amps for any significant period of time. I have an Alltrax 500 AMP controller that has adjustments available for Max Motor Amps and Max Battery Amps. Should I reduce one or both of those to try and avoid the BMS shutting down under heavy load?

i got mine in march as well and had the same issues except for the reverse. i dropped max battery amps to 350 in the alltrax settings and it has been fine since. when it would cut off before that i'd either unplug the negative or reset it from the app.

as far as the 12v connections on the battery, i'm lost. my lights haven't worked since i got the battery. maybe my 12v posts don't work either. my radio, underbody LEDs, and usb plugs work. i've checked every fuse on the cart as far as i can tell. no clue. i love the battery though.

[weekster]

Originally Posted by dawgfan316

i got mine in march as well and had the same issues except for the reverse. i dropped max battery amps to 350 in the alltrax settings and it has been fine since. when it would cut off before that i'd either unplug the negative or reset it from the app.

as far as the 12v connections on the battery, i'm lost. my lights haven't worked since i got the battery. maybe my 12v posts don't work either. my radio, underbody LEDs, and usb plugs work. i've checked every fuse on the cart as far as i can tell. no clue. i love the battery though.

In talking to the Extreme Team folks, it seems my 12v converter is bad (indicated by no voltage on the posts and the light on top of the battery not working). They are sending me a new converter. I also learned that if you draw more than 100 amps from the 12v connection, it won't work.