Lithium Charger not staying on

[rose88]

GUD 72v lithium cart and friend has tried 3 chargers and all cut off 2-3 sec after turning on. Checked with a volt meter and none are puting out voltage.

Anyone know the reason or dealt with this before?

No name on nothing (batt,charger,etc...)

[jasonojordan]

Sounds like the battery is in a state where it will not accept a charge.

Whats the voltage read on the battery? Have you tried a power supply rather than a smart lithium charger?

[rose88]

Originally Posted by jasonojordan

Sounds like the battery is in a state where it will not accept a charge.

Whats the voltage read on the battery? Have you tried a power supply rather than a smart lithium charger?

75.1v shown in pic is where it's at. I have tried the charger by itself and no voltage output hooked up or not all 3 come on and shut off within 3 sec.

[jasonojordan]

Sounds like the BMS is limiting charging but is still allowing discharge. Have you checked to see if the BMS used has bluetooth?

[rose88]

Originally Posted by jasonojordan

Sounds like the BMS is limiting charging but is still allowing discharge. Have you checked to see if the BMS used has bluetooth?

I have not and this system has no lables of make other than GUD on nose of cart. It runs and runs well, AC set up 72v
Battery voltage sitting is 75.1v and shows 46% on gauge.

Shouldn't the charger put out just plugging it in to 120v power ?

[rose88]

Ok maybe the gauge BMS is malfunctioning? Im getting 75.1v @ rest sitting to me thats above the 72v system but Im not sure what the rating of this cart is?

Charger should still show above that when charging correct? It comes on and kicks off within 3 sec telling me that either this 3rd different charger isn't working or there is something keeping them from charging.

Should I be able to just plug charger in and hook volt meter to charging plug and get voltage when powered on? without being hooked to battery?

[jasonojordan]

Depends on the charger and how it works but I would assume that for a period of time it should output voltage at least without a load.


What I had found searching 72v Lifepo4 SoC Chart

Lifepo4 Voltage State of Charge Table 72V


Charge state (SOC) Battery voltage (V)
0% 60V - 63V
10% 63V - 65V
20% 65V - 67V
30% 67V - 69V
40% 69V - 71V
50% 71V - 73V
60% 73V - 75V
70% 75V - 77V
80% 77V - 79V
90% 79V - 81V
100% 81V - 83V

[rose88]

Originally Posted by jasonojordan

Depends on the charger and how it works but I would assume that for a period of time it should output voltage at least without a load.


What I had found searching 72v Lifepo4 SoC Chart

Lifepo4 Voltage State of Charge Table 72V


Charge state (SOC) Battery voltage (V)
0% 60V - 63V
10% 63V - 65V
20% 65V - 67V
30% 67V - 69V
40% 69V - 71V
50% 71V - 73V
60% 73V - 75V
70% 75V - 77V
80% 77V - 79V
90% 79V - 81V
100% 81V - 83V

46% is what gauge is showing and meter is 75.1v Not far off from they're chart.

[TheCartBoy]

Is there any kind of communication wires between the charger and battery, or is it just ,+ - ?
Any kind of communications between the battery and the controller?

If there are no smart comms, you should be able to put the cart on jack stand, disconnect one lead from the battery, connect the charger to the battery leads going to the controller and drive the cart off the charger alone, just to prove the charger works.

[rose88]

Originally Posted by TheCartBoy

Is there any kind of communication wires between the charger and battery, or is it just ,+ - ?
Any kind of communications between the battery and the controller?

If there are no smart comms, you should be able to put the cart on jack stand, disconnect one lead from the battery, connect the charger to the battery leads going to the controller and drive the cart off the charger alone, just to prove the charger works.

Yes it has a 2 wire connector going to controller and a triangle connecter from charger to light above charger port