Thanks. I can't find any loose connectors. Double checked all fuses, verified ignition and kill switch are open/closed in their proper positions. My understanding is there is a contactor/relay in each battery but I don't hear it clicking and I don't know how to manually verify it. BMS LEDs aren't on, and a BMS reset doesn't do anything.eee291 wrote: ↑Apr 29, 2018 4:07 pmI would check the wiring first, if you can't find any loose connectors. Doesn't the bike have a DC contactor/relay? check if it switching/seized or if it is getting power at all. the next thing I would do is to check the wiring Diagramm of the controller and start measuring the voltages.
The ignition is definitely fine. I tested continuity.eee291 wrote: ↑Apr 29, 2018 6:31 pmWell the reason for the 12v converter to be unpowered is because the battery isn't supplying juice to it.
Now I can only think of two things:
Either the battery has a fault (wouldn't blame it for it's age)
Or your key switch is broken entirely (Less likely in my Opinion, but you can switch the wires manually if you dare fiddle around)
Also the Controller should have two thick wires on the input, check the wires if it's getting main power, to see if it would just need to be switched on.
Sure, photos here: https://photos.freerobby.com/Projects/Zero-XU/
Yeah, the 40V measurement is at the controller B+/- terminals. Good point about caps in the controller.eee291 wrote: ↑Apr 30, 2018 1:54 amCan you also measure 40V on the controller terminals? I'm guesssing the Capacitors in the Controller usually hold a charge.
Also what's up with the 40V? If the battery isn't charging shouldn't the charger float somewhere closer to 60v? 40V is below the BMS cutoff.
I think you should investigate on the charger side also.
Sad to hear.robby wrote: ↑May 02, 2018 5:07 pmUpdate: both batteries are deep discharged... 15.7 and 18.8 volts. Zero tells me there is no salvaging the cells. Cost of replacing them and the chargers is 3x what I paid for the bike new in 2015. I'm so bummed. Will investigate how much it'd cost to rebuild the battery packs but I'll likely be parting it out in a few weeks. If anybody needs any XU parts, let me know.
I'm not so sure about that. There may be a way to revive the cells if they were not reversed during discharge. When cells get below a certain level, normal charging current can permanently damage them. A very low charging current (maybe C/100) is needed to bring them up to the safe level, then the current can be increased. I've used many cells that have been brought back from zero volts and they seem to perform normally.
I'm in northern MA. Happy to part out what's left (blinkers and foot pegs? lol) if I wind up scrapping it.
I'm considering this. I don't even know if my BMS are any good though, and I would hate to rebuild the battery packs only to have yet another proprietary parts project on my hands. Are the Leaf cells the same voltage spec as the originals, and if not will the BMS monitor them properly?
Whoa, interesting. I had no idea. Zero sent me a diagram (see attached) indicating how to read the actual pack voltage (I wasn't using the main contacts). Do you think charging would be blocked at those pin locations as well? Regardless, I have little to lose by opening the battery and giving it a shot.fechter wrote: ↑May 03, 2018 2:10 pmI'm not so sure about that. There may be a way to revive the cells if they were not reversed during discharge. When cells get below a certain level, normal charging current can permanently damage them. A very low charging current (maybe C/100) is needed to bring them up to the safe level, then the current can be increased. I've used many cells that have been brought back from zero volts and they seem to perform normally.
The BMS is likely inhibiting charge at this point, so the only way is to take the pack apart and get access to the actual cell connections. It's possible the pack is potted in a way that makes this impossible.
If this is the case, it may be possible to put the low current charge into the main discharge wires going to the controller.
Since your other options involve replacing the cells, there isn't much risk in attempting reviving the cells (other than increased fire risk).
Charge in a fire-safe location.
Well, that's higher than any of my batteries, so I don't have anything that goes that high. The current sounds OK. Even 500mA would probably be OK to bring them up.robby wrote: ↑May 03, 2018 5:02 pm
Whoa, interesting. I had no idea. Zero sent me a diagram (see attached) indicating how to read the actual pack voltage (I wasn't using the main contacts). Do you think charging would be blocked at those pin locations as well? Regardless, I have little to lose by opening the battery and giving it a shot.
So for C/100 of a 2.8 kWh pack, you'd recommend e.g. 116V DC @ 241mA, yes? Any charger or power supply you'd recommend for this? (The bench supply I have access to tops out at 60V).
Battery Flowchart Rev01.pdf
I was just going by the nominal rating. Ideally once it reaches a certain point the BMS would reactivate and take over, but I wasn't sure if I should be trying to trickle charge all the way.
Thanks, I wasn't sure if I should expect those pins to be current-limited in some way. Hopefully for the trickle charge it shouldn't matter.fechter wrote: ↑May 04, 2018 7:47 amWell, that's higher than any of my batteries, so I don't have anything that goes that high. The current sounds OK. Even 500mA would probably be OK to bring them up.
If you can measure the voltage on the pins, then it means you can charge through them. If you can access sections of the pack through the connector, then maybe you can find chunks that are under 60v and you can use your bench supply.
Another trick I've used before is to place another power supply in series with my bench supply to get more voltage. To do this you need to put a big diode across the output of the bench supply to make sure it doesn't get driven negative by the other supply (I've blown up more than one supply by not doing this). The diode needs to be rated for a higher voltage than the supply and you place it across the output reverse biased, so it is normally not conducting.
Keep in mind I have no direct experience with this particular type of pack, but all Li-ion batteries have similar behavior. I bet Liveforphysics would know exactly.
Do you know who did this? I'd like to get in touch with them.
Thanks. My main concern is replacement cell voltages not lining up with the originals and the BMS not liking that. Good to know others have had success. Appreciate the thread link and Dr Bass reference. Good to know there are folks who've gone through this with Zeros even if not the exact same battery pack.
I think nominal is 102, max is 116. Don't quote me on those exact numbers, but they're close.eee291 wrote: ↑Jun 02, 2018 2:32 pmWhat's the nominal Battery voltage? I thought it was still 48V, but I can't seem find anything on google.
I guess you could trace the 12V converters input back to the relay/solenoid, and bypass it to apply power just after the relay.
It might throw you a battery error light or something but it should be enough to check if it is functional.