Print

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

[CurtG]

Just one BMS was replaced.  That battery is the one the dealer says won't take a charge now.  Before the BMS replacement, he said it would not communicate.
When I get the bike back I will try keying it on, but I don't think I can tell by ear whether both contactors close since they seem to close simultaneously.  Hopefully the "bad" battery will have enough left in it to operate the contactor when I remove the "good" battery.

[DonTom]

Just one BMS was replaced.  That battery is the one the dealer says won't take a charge now.  Before the BMS replacement, he said it would not communicate.
When I get the bike back I will try keying it on, but I don't think I can tell by ear whether both contactors close since they seem to close simultaneously.  Hopefully the "bad" battery will have enough left in it to operate the contactor when I remove the "good" battery.

The double click can usually be heard, there is usually some difference. At least there is in my Zero SR with the Power Tank. And the timing between the two varies, sometimes more than a second difference, but usually a lot less, but still enough to notice.


-Don-  Reno, NV

[MVetter]

Yeah there's definitely an audible *ti-tink* of the two contactors clicking at nearly the same time. But it's easy enough to kick one battery out at a time and test as well. If only one clicks and operates the bike... well for now you've got half a battery at least and can use the bike to a degree.

If *both* batteries click then it is definitely possible to charge both. From there the question is, "is the BMS monitoring things like it should" which is hugely important.

[Curt]

If it's a modular, why wouldn't you have tried charging it and running it with one battery at a time? Or did you and just not mention it?

Remember, you have to plug in the blank connector in place of the missing battery or it will NOT work.

[CurtG]

It's still at the dealer.  I haven't had a day when it's safe to ride home (probably in 2 stages since the range is now half of what it was) yet; the roads are icy.  I will try isolating the "bad" battery then.  I'm very disappointed that Zero simply gave up and told me to buy a new battery; I expected more from them.  I'm grateful to all the people offering advice here.  It would be wonderful if you guys are right and the battery itself is salvageable.

[Curt]

Darn, the dealer must be correct that one battery is just dead and a new BMS didn't help. Now I do wonder if a BMS firmware upgrade gone wrong could kill a battery. Maybe the battery got slowly drained too low. Maybe it could be resurrected using an external charger according to other threads on here.

Good luck! If you lived around here, I'd offer some help to get it back. Maybe something like this?:

https://www.ebay.com/itm/276024611671?hash=item4044595357:g:ZKAAAOSw7lpj~j4v&amdata=enc%3AAQAIAAAA4N3Y24oPedPlnFfPnm1xEytiUf2jkEYh3ycPN%2BHPP8M0CpSzi27JKkhkPrnEwLkxyRTM2rUXR54K8f3DQ%2FlPqrwrqidzTAEL%2BRgjDGmbbRPlbMPyw1g1DcvfuBkZ2drAgEy2GshRiOnbcE%2FITELosGZpoLEbTgEAE%2Bhkp0xb5dsyzvQrft1JDpfBdex0A4cNDfLlGxRsONrqhiKwNsY%2FEJYBJ1Euc4EhZVPNFyxlpxHRVjZfIleMTKpBgXv4g5TjvMRCxl%2BatfKw%2F7Qx9c%2BvuI6xTR2sV18zjur6nO5Ont%2Be%7Ctkp%3ABFBM_O_9-Ypj

[Specter]

A battery CAN be resurrected if you took it to zero.  I have done it several times BUT the chemistry is crucial.  LiPO's are going to be very touchy to refurb, and there is a BIG chance you have dendrites which will soon short the battery out and cause it to go woof on you.  You can hook them to an external charger and slowly bring the voltage up to where a regular charger will 'see' it and go to work on it, and then give it a gentle charge until it's full.

How long it has been sitting at zero and age play a huge part on its reliability and safety afterwards too.  If you like to tinker have at it, but to be totally honest,  in my shed where I have 'those kind' of projects in a metal box is one thing, but under my ass running down the road... is another.  if it does decide to go, it will do so quite thermally and with quite the display too !
Aaron

[MVetter]

There is absolutely no reason to assume the battery is below its standard 0% value. As a general rule, though, it's a very bad idea to try and bring a cell back that has dipped below 2.00vdc. On a Zero that would be a pack reading of 56vdc or below.

[Specter]

+1 What Morgan said,  if the battery is defective and you somehow managed to get it to zero volts.  You are playing woth fire LITERALLY by trying to resurrect it and expect it to be viable / safe.   
A LiPO is a nasty beast with a ton of power density.  The Ferric chemistries you see in the home batteries, the solar storage, the solar walls, are a different world.  They are much more forgiving when you abuse them, and a LOT L O T  less likely to ignite when abused.   Because of the way the LiPO's work, they create crystalline tendrils inside the cells that like to grow and short across the plates.  Once that happens, you get a ton of heat as that cell that just shorted expends it's load thru that short.  Things melt, things burn, this causes a HUGE short now. 
They will hiss, and then flame, because one of the byproducts of that is Hydrogen gas, which you just heated to hundreds of degrees and are throwing sparks at it from an internally shorting battery.  The rest of the batteries in the circuit will now want to dump their load into that dead cell since it's a strong current pathway, not to mention the 1700 degrees plus that thing will burn at once ignited, the heat transfers to the pouches next to it, they melt, they short, and they sympathetically deflagrate.  Thermal runaway happens fast.

Please be VERY careful if you genuinely have to rezz a totally dead LiPo.  Sometimes it isn't worth it

aaron

[TheRan]

While it still wouldn't be advisable to try and save it if it's gone too low, Zeros don't use lipo's

[Specter]

What chemistry do they use?  The ferro while MUCH safer does not have nearly the energy density of the Lip's though.

Aaron

[TheRan]

Lithium iron phosphate, or LiFePO. Zero has said that they purposely gave up energy density for durability.

[CurtG]

Thank you all for the advice.  If the battery is indeed below 56V, I'll be safe and give up on it rather than try to resurrect it.  However, if I find a bad contactor or something, I'll try to fix it.

[Specter]

If it's at like 53 volts or 50 volts, you should be safe, go easy but if it's sitting at like 15 volts or zero then you trashed them pretty badly.

I had some Iron phos batteries that got sucked down to zero because the first run of them they hooked the internal heater up apparently on the power side of the bms, so on a cold day the fuckers sucked to zero, NOT happy about that,  after much complaining and a few threats they sent me new batteries that were built properly this time.  Told me to keep the old ones they were not going to pay to ship them back,  opened them up rewired them PROPERLY and used a standard lead acid charger on them in recovery mode to slow charge them up to a voltage that the normal Lith charger would start on them, did a few full cycles on them and a good balance and they seen no worse for the wear.

LithPhospate is much less susceptable to thermal runaway and some of the issues the LiPo have, and can take quite a bit more abuse than the lipo's.   

Determine for sure, what chemistry you have, and what the voltage really is on them, and we can go from there.  PS if you have an old fashioned ie CHEAP battery charger for 12 volts that is NOT one of the digital pieces of crap, you may be able to use that.  you'll need access to the battery cell hookups / bus.

Even if the battery runs at 56 volts, you can in theory break it into 12 volt sections for charging each 'segment' to resurrect them enough to the point the normal charger will recognize them.

More later,  Lets see what you really have first.

Aaron

[CurtG]

According to this site: https://zeromanual.com/wiki/Battery/Cells the 2015 FX uses NMC (lithium nickel manganese cobalt).