Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Ramsay Snow]

So I bought a crashed SR/F. Looks like it's been sitting for a while and was totally dead. I got the 12V out and charged it. Got it to turn on, but the main pack is also dead. My planned next step is to try and charge it from a level 2 and see if it comes back. Anyone have better ideas? should i maybe try level 1 to start with to bring it back slowly? other suggestions?

[talon]

Keep the pack WELL away from anything flammable just in case. A wrecked bike's lithium battery can never be fully trusted.

I don't think charging rate matters too much, but slow would probably be good better to keep balance (if one or two cells sat low and were heavily degraded, you want to give the BMS as much time as possible to balance them) and not generate too much heat (internal stresses).

Edit:  I worded this poorly and without much thought--I don't know all the details. To a point, it is either functional or it isn't, but charging rate does indeed matter. The BMS should keep it all balanced but there is never a guarantee the BMS or even the charger is working. You shouldn't attempt to charge cells that have any type of damage. I don't want this to sound like I'm encouraging you. I've worked with wrecked Zeros in the past and I understand it's a fortune lottery with unknown odds that you don't want to win.

I would love to see some pictures! It's interesting to see how most bikes absorb impacts.

The question really is, how dead was the main pack and for how long. See if you can download logs or connect via an app. A software voltage reading would be most useful. Also, any signs of impact or contact with the battery case?

[Ramsay Snow]

So charging failed. After some diagnostics I took off the front plastic cover to find the flex cable going from the BMS board to the pack got sliced in half. Looks like its a fairly standard 44 pin flat flex ribbon cable. Zero will only sell the entire board with the cable to a dealer for a ton of money, so next step is to try and fix it or find a 3rd party replacement.

[talon]

If the impact were that severe--to affect parts internal to the battery, really weigh the risk here. It may not be salvageable and the smallest thing not inspected or analyzed trying to return this to service poses great danger. Heck, even doing nothing at all and simply storing it does as well. I only say this because I do not know your qualifications or experience with large lithium batteries. Things can go bad very quickly and you need to be prepared, or stop altogether. Newer Zero batteries should have a novel packaging with epoxy coating the cells, but there is still a lot of chemical energy stored there. Just realize with anything you read here (from myself and others) you are still continuing at your own risk and our posts are not the advice of experts, just postulations based on limited experience.

That being said, are there any witness marks or deformation to the body of the battery that houses the cells? What caused that tear? That kind of force could cause an intermittent failure in the BMS.

[Ramsay Snow]

No, the batt's fine. the bike went into a car pushing the front wheel into the plastic shield on the front of the batt. That ribbon cable is right under it, so the plastic rib of the shield just cut the cable.

[talon]

Well, I would personally safely measure the voltage at the doghouse on the contactor to assume what the voltage per cell was. But I don't even know if the newly-designed SR/F batteries have the doghouse. I think we would all appreciate lots of pictures or even a simple video if you have the time.

I wasn't aware the battery even had a plastic shield. You could order a similar cable from a components supplier if you match the pitch, but I can't see how it is terminated or what it is used for.