2010 CC Precedent Dies but comes back by removing/putting back Cart Negative

[TNdave88]

My father bought a 2010 Precedent I2 Excel and when it works, it works great, but it will intermittently die after moving 30ft or so. No roll away buzzer, or lights, nothing works. Resetting run/Tow switch, key switch, F/R switch does nothing. Strangely removing cart negative and replacing seems to reset everything and it's back to normal immediately. Has brand newish 48V Lithium batteries charged to 52+ volts. Brand new cables. OBC bypassed and Blue/white pins jumped together. I'm decent with electrical (HVAC tech) but unfamiliar with these systems. I was under the impression the tow/run switch was kind of like a disconnect, yet only removing cart negative and putting it back fixes the problem. I would think the lights circuit would be separate from the solenoid or do they also lose power with a bad solenoid? Is something still energized in the circuit that gets reset by removing the cable that doesn't with the T/R switch? I'm just not sure where to go next. To me it seems like something is turning off the controller or getting stuck and once reset It works. I just don't want to buy a controller or solenoid when it's something else, I don't like being a part swapper and hoping for the best. Any direction would be greatly appreciated.

[Volt_Ampere]

This is a problem with your Lithium battery system. The BMS is shutting down due to "overcurrent" or some other fault. You are resetting it by disconnecting the battery. You will have to deal with the battery supplier to resolve this.

[CP241]

I’d double check the OBC bypass. It sounds like it is behaving like the controller is in OBC lockout. Make sure the blue and white are jumped on the correct side of the connector. Either that or your battery is defective, check voltages

[Volt_Ampere]

Easy to check this. Measure the battery voltage when it's shut down.

[TNdave88]

Battery voltage is fine when shut down and individual batteries are 13.1 to 13.3ish. I've had a lithium battery bms go bad before and it caused high resistance and no voltage reading, these seem to test fine when it happens that's why I'm Not sure.

[TNdave88]

OBC blue white wires are definitely jumpered on correct side of harness. That was my first thought because I read something about the controller going to sleep or something when not getting signal from OBC

[Volt_Ampere]

Then it sounds like CP241 might be right.

[CP241]

Originally Posted by TNdave88

OBC blue white wires are definitely jumpered on correct side of harness. That was my first thought because I read something about the controller going to sleep or something when not getting signal from OBC

That’s exactly what happens. Controller gets locked out until it sees a charge cycle, and disconnecting the pack for a minute resets it. I’d double check the connections then. What method did you use to jumper them? I’ve never owned a precedent so I really couldn’t help with specifics on exactly where the wires and etc… I’m sure there’s others here that could be much more specific than me, but I’d do a gut check and double check that before diving too deep. Sure there’s other things that *could* be the cause but I always like to start simple.

Double check the bypass and check voltages under load while you’re driving the cart when it cuts out and dies. The 4x12v configuration has been known for being less than ideal and since each battery has its own BMS in it, it could be one battery chunking then whole system.

The other question that remains unasked yet, did the cart ever work before and is this something that came out of the blue? Or did you add the batteries and bypass the OBC and now it’s doing this, and has never worked with this configuration?

[TNdave88]

Cart has had this problem before the batteries but not near as often, I just called and had him call the previous owner. The carts OBC was bypassed previously but without jumping blue and white, so I completed that because I thought that was the issue after researching. The jumpered wires are soldered and heatshrinked (is that a word lol). What are voltages supposed to be while under load? I haven't seen anything crazy on the the SOC that would make me freak, but again I'm not familiar with these. I have been seeing in the mid to high 40's?? And something like mid to high 2Kw to 3.3-3.4Kw current draw while running?? It's so random it's not like it dies after working hard or anything. It's always while pulling out of garage under light load. I'll be over there this weekend to do more testing. I have however taught my father how to use a multi meter to check the voltages over the phone that I never thought would be possible haha.

Question, I definitely could have messed something up, though I'm pretty confident in my soldering skills - when I first jumped the blue and white I wasn't paying attention and did the wrong side of the harness, saw it, and just did the other side but left the initial side there (I think) because I figured it wouldnt matter considering the circuit was closed on the the other side with the new jumper. Is there a way for a signal to be sent wrong with the un used side of the connector jumped like I did? I'll cut it either way tomorrow, just wondering. Thanks for all your help BTW!

[TNdave88]

Also is there a place I can test continuity of the blue white jump at the controller or something?