60v 30ah scooter shuts down after a minute or so of load

[RoliRoliRoli]

my scooter shuts down after a minute or so of load and it was running fine until my throttle display /instrument panel had broken and I replaced it with a JP-24-60 which worked when i programmed the P setting for it to be of the correct voltage. I did notice though that my top speed wasn’t quite right for I was capable of getting in the 50s on flat ground.My cells shouldn’t be misbalanced because when I charge it gets to 67.3 when my charger light. Comes on green for full charge. I did mess with the P- settings again and raised the undervoltagge cutoff to 60v from 50v hoping to get my speed level back up but my scooter wasn’t fully charged and ended up shutting down. That was because my scooter was prolly only holding 55-59 volts and from that day i have been having problems.today it died at 64 volts and I brought it in and tested it from the battery to controller xt60 and got 55 volts , then Other connector 48.5 volts .I currently working on it as I speak snd hope that somebody here can give me some help advice feedback …I want to diagnose the controllers but am unsure how.I have Everything unhooked. Besides the 3 hall sensor wires which are sealed with heat shrink over maybe
buttconnectors ,I do have a fluke voltmeter so if anybody can assist me with what to test for my guess is start off to check continuity from the wires coming from the dash first. Maybe there is something loose drawing amperage from the battery?? The voltage will go from 67.3 down to 63-64 in a minute then shut down from rhere.

 

[fechter]

When it shuts down, does the display stay on?

Sounds like a battery issue either way. Can you access the battery BMS board? It would be good to measure each cell group in the pack. It may be out of balance or have a bad channel that drains one cell group.

 

[RoliRoliRoli]

The display stays on until voltage drops under 5v on the dashboard voltmeter/voltsge lock….I noticed it said 2 different voltages when I had checked the charger port was at close to full voltsge and the batteries controller xt90 read only 48.5 which is right before the bms usually would kick on for lowVOcutOFF. What’s the best way to open snd balance each cell without cutting the nickel connections?

 

[fechter]

It depends on how the pack is constructed. Regardless, you don't need to cut any of the nickel strips. You can charge individual cell groups with all the strips intact. In the past, I've done it using the balance wire connector going to the BMS board. Unplug the connector and use skinny solid wires to insert into the connector. You can use the same approach to measure the voltages. Just be really careful not to let the wires touch anything.

 

[RoliRoliRoli]

So what charges must I use then ? Do u need a special charger like a fly RC or something i dont have lol…i have a bench power supply deep in storage someplace but I might be better iff just ordering something new

 

[RoliRoliRoli]

What if I was to https://a.co/d/fGAJVb5

 

[RoliRoliRoli]

It’s a active balancing unit with Bluetooth

 

[fechter]

Step one is to check the cell voltages. If you have one that's trashed, replacing the BMS won't help.
I charge single cells with a bench supply. I also have some cheap single cell charging circuits that are powered from a 5v phone charger.

If the only issue is your pack is out of balance, then active balancing might fix it. It might take a really long time depending on the balance current.

 

[RoliRoliRoli]

Do you think it’s worth getting the 100balance brand active balance…Im going to put in a order today to work on my battery…i have a rechargeable portable spot welder with pedal in storage but digging through that mess is not in my favor so I might just order another one…also was going to order the active balancer some shrink wrap and kaptom tape….is there anything else I should order???

 

[RoliRoliRoli]

This is the bms i have and I checked the balance wires and also the cells individually (while still connected to their parallel cels and found that the 2nd row from the last is showing 0.8v and the rest of the packs groups are 4.15 ….so now what’s the safest option for extraction here ….i have one side thats connected to the negative side and the other the positive…also I have cells laying around what do I have to make sure of I know they need to be charged to same Voltage and should have the same amount of mA….heres photos of the row thats no good …