I stored the battery at 86v about four months ago and now it won’t charge.
I checked the voltage at the battery connector with a multimeter and get 46v which is too low. I’m not sure why it would continue to lose so much charge after only a few months.
I tried pressing the button on the round BMS thing inside the battery as outlined here:
However the battery still doesn’t charge. I haven’t had any rough landings or done anything that I can think of that would cause this.
I bought this thing thinking it would be more reliable than gas… already it doesn’t work
The only way to recover your battery is to remove the case, bypass the BMS, and manually bring the cells back into an acceptable voltage range. Afterwards the BMS should unlock and allow resumed normal operation.
To do this, first check the 24 sets of parallel cells ensuring that none are much lower than the rest. The farther apart the cells are, the greater the risk of future battery failure or even fire. Afterwards each individual bank will need independently trickle charged up to 3v. Get the voltages as close as possible, otherwise it could literally take the BMS a full month to ballance the cells. Reassemble the pack and monitor closely for the next few months to ensure that you don’t have a parasitic drain.
This will have risks for both the short and long term. There are risks when working on a high voltage battery pack. In addition, going down to 1.9v/cell will most likely have caused a few percent extra degradation. Long term, this also poses a slightly increased risk of a fire down the road. From personal experience, it has over a 99% chance of being fine, but you need to weigh the risk.
Thank you very much for your help! It sounds like even when I get the battery up to charge again there will likely be something wrong with one or more of the cells causing a parasitic drain. Maybe open PPG will let me exchange the battery for a new one… I sent an email and will see what they reply
Most of the time the cells if not stored with at at least 3/4 of full charge on every cell of the winter. The cells will collapse and you won’t get the voltage out of them. There’s only one answer replace the cells it’s an expensive.
I’ve repaired a few battery packs in the past people using the 18, 650 cells which are probably the best on the market for what you can get.
if you want to try and get your unit repaired may even be more cost-effective to scrap the battery pack and just start again once the voltage dropped the crowbar in the circuit that monitors the voltage of the batteries gets to certain point and once there a little Zenner Diode in there won’t turn on and that point you’re about knackered. Sometimes you can manually overcharge the batteries but extreme caution when you do that and sit on it while you’re doing it because if anything starts to get warm you need to be stood watching it while you’re doing it.
Do not leave it on manual charge because if anything does go wrong and you don’t pump the voltage back into the cells and you can only do that on a manual charger, not an auto charger that’s when you get fires starting.
You’ll need to spot welder for Welding new sell in then you want heat shrink foam, wrapping gaffer tape, plastic sheeting stuff like that it’s not a quick two minute fix and it’s by no means cheap or easy. Even somebody like myself is done quite a few of them there , good luck
Ranger good luck with it do let us all know how OpenPPG reply.
This is a very worrying, time consuming and possibly expensive problem.
I’ve just bought a used unit and your story fills me with dread I had to store my battery on 100% which Im told is not the thing to do but had no choice as I bought a unit a day before I left States for winter no time to mess around discharging by any method.
Now you Ranger did discharge to recommended storage value and got screwed.