Battery not Charging

[Warwick]

My Panda Pro kit's battery, bought from BGA isn't charging. I wondered why only 3 lights on the battery case lit up.

It was fine until I stopped using it about 6 weeks ago, and since then it's been stored on the bike, with one charge during the lull.

The bike worked fine last week when I took it out on a test ride, so that's OK, it just isn't charging with a charger I've used before with it, and that has just charged up my Oxygen without issue.

Any tips or ideas?

 

[Deleted member 4366]

Measure the voltage on the charge socket. 0v means the charge fuse has gone. 0.1v to 25v means the BMS has switched off. Anything over 30v means a faulty charger. Those statements are something like 95% true.

 

[Warwick]

Naiive question: I have a multimeter & know how to use that, but how do I take a measurement from the charge socket? Is it a fiddly job of placing one pointy thingy (technical term) on the tiny terminal in the middle of the socket and the other pointy thingy on the outside terminal of the socket?

 

[Deleted member 4366]

Yes, if it's the Jack type, you have to be very careful not to short it, which isn't easy.

Pro tip: use a spare jack or buy one to plug in, then you can get your probes safely on its terminals or leads.

 

[Warwick]

Right, I've secured a plug so I can strip the wires and check the voltage.

I know it's not the charger, as it charged my Oxygen fine. If it's the fuse, I'll know what to do, but if the BMS has shut down, what are the next steps?

 

[Woosh]

what are the next steps?

the first step is to find out if anything rattles. If it does, then locate the source of the rattle.
The next step is to measure the voltage at the balance wires.
They are usually marked B0 to B13. B0 is ground, B1..B10 are used for 36V packs, B1..B13 for 48V packs. Measure the voltage between B0 and B1, B2..and B10.
You should see increment of between 3.1V-4.1V
Anything out of the 10% step will stick out.
Next step, see how lucky you are.
Unplug the balance wires, wait 1 hour, plug them back in. You may be lucky.
If not, post your voltage readings here.

 

[Nealh]

Check the cell group voltages any one group giving a high (4.1v +) or low voltage will stop the bms from switching. Depending on the bms lvc it may not allow charging if a cell is below 3.3v, whilst not in use a cell group may have bled down voltage wise in which case the bms will be at fault.
As Woosh have said post your readings you expect to see 10 fairly equal readings if the battery is balanced.

 

[Warwick]

Fortunately, the battery is under warranty from BGA & is going back to them a) once I've found the key to remove it & b) once I have packed it up & given them the dimensions.

 

[Warwick]

I had a d'oh moment earlier. I wrapped up & packed the battery and measured the box sizes, as requested, then set about replying to BGA's email. They only asked me to send the charger as well! I can't think why, as they must have hundreds! Well, I suspect they wanted to eliminate that as the source of the problem, I suppose. Well, it ain't; it's charging my Oxygen battery too very nicely.

I hope I don't have to open the box up to put in the charger!