Print

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

[sylvanascent]

I got some new batteries and chargers last year (thanks Zero!) , haven't used them much, but already one of them starts blinking the red light on the charger after an overnight charge. Yesterday, I went riding, and that same battery started beeping and cutting out about half way through the ride. Had to find a place to charge(luckily I brought along the charger). Any ideas on how to debug and fix what is wrong?

The charger firmware is ALGID99-V1.10

These batteries could have been designed for fixing, instead they seem to be throw-away after one year items??!!??

Thanks!
Roger

[zap mc]

keep a note of the voltage on the batterie(S)
should be about 58v
pull the end off the battery and measure the cell rows to check for imbalance, each of the 7 rows should be about 8.2 v fully charged
get the charger upgraded to 1.14 too
some chargers do put the red light on for some reason after a charge but it they are doing to job of charging it up then dont worry its just a pain to leave it on charge
what battery have ytou got early type with two plastic ends or late type with one aluminum end?

[sylvanascent]

Thanks for the information. In the meantime, I've come up with some more information. Yes, it is a self balancing version (aluminum end), and I popped the lid and took readings of each bank. Actually, you have to read each 1/2 bank, there is a wire coming out of the middle of each bank that connects to the 1/2 bank. There was one 1/2 bank that was a little low, about 4.04 instead of 4.12 like the others. I used a digital power supply to charge it up to match the others, and it seemed to work a lot better, going to green very quickly.

In my charger version, if it goes red blinking after trying to balance all day, this is bad. Don't leave it this way. Unplug the charger, wait 15 seconds, then plug it back in to have it try to balance the banks again for many hours. Keep doing this until it goes green again, otherwise the battery may discharge completely while blinking red for a month, and you'll end up with a dead battery. Also, if you go on vacation, have someone check on it, or maybe put a timer that turns the charger off for maybe 30 minutes once every 24 hours. That way at least the charger will keep trying to balance and you won't come back to a dead $3000 battery!

In my opinion, the Zero battery design is not a good one. It should be possible to swap out bad banks, instead of buying a whole new battery because of one bad cell. When you figure that there are almost 300 cells in the MX battery, this is good odds of eventually having a bad cell! I can't even imagine how many cells are in the new 6kWh S and DS!

 Currently I have a battery with 12 good banks and two bad ones, and likely it is a single bad cell in each bank. No way really to repair it. Any ideas? My 2 amp digital power supply can't bring up these banks past 1.2 V, and when I disconnect it they go back to 0 in about a minute.

[frodus]

what charger is it? the deltaQ QuiQ?

http://www.delta-q.com/documents/710-0098_User_Guide_Rev_1.pdf

Second page tells you what the errors are.


If you're trying to charge up and one cell group never gets past 1.2V, something let that battery pack overdischarge, or you have a shorted/bad cell. Something is pulling that group to "zero".

Have you spoken with Zero?

[zap mc]

Thanks for the good information form you both, very helpful, i have a pack in bits and am tryiing to restore it. I have previuosly sucessfully swapped out a dud row and restored a battery. What seems to happen is that when they are all connected you get some at about 7.0 and some at about 4v (measuring the full span between the two braided ends) if you strip the cells out of the housing (bitch of a job) you can disconnect the copper straps that join the cell rows and it is then that you will discover the true values of each row as some will drop to zero indicating a short in the row of duff individual sell or cells. It is my theory that because they are all joined that the duff rows are supported by the good ones and that they do not allow them to drop to zero but are constantly leeching power off the good cells.
I do not understand what the difference is between the self balancing aluminum ended packs and the old style plastic ended ones, can anyone enlighten us?

Yes it is not a good design but in theory we could find a way to restore them by logical process and measurement. It is relatively easy to swap out a cell row but i am interested in diagnosing the individual cell and replacing that if it has not contaminated the whole row. In order to do that we will have to split the plastic heat shrinking that encloses the rows.

Inside that there is a row of double cells whicjh are held together by elastic bands which are held together by a friction fit to the braiding. this is the patented part of the battery and the theory is that it guards against vibration damage as it is flexible.

I would also say to check the fit of the small spade connectors to each cell row as i have found some of them are loose and only held on by the actual hot glue which has meant that the bms cannot get a proper reading from the row and hence cannot charge it properly.

I would also like to know what the centre braided small spade connector is for and the other spade connector as they both feed into the internal bms box?

I have asked Zero to supply a separate row and will wait to see it they will.

[sylvanascent]

Actually, Zero replaced the bad battery about 1.5 years ago, so I've got no complaints there. Just would like to see if I could get the bad one working again, seems a waste to throw it all away just for a couple bad cells.

I've also taken a row apart, it looks really hard to get it back together again, what with the shrink wrap having to be cut off (without cutting the rubber bands), then finding the bad cell(s), replacing these, then trying to put it all back together again. Humpty dumpty.

I think there is no balancing on the old non-aluminum ended ones.

Also, it seems that if you are getting a fast tic-tic-tic from the BMS, it means at least one half bank is at zero volts. DO NOT try to charge the battery in this state! You will likely get a lot of pops as the cells blow (at least that happened to me, not a happy day).

The center braided connector joins to the middle of the double row, and gives you access to each half row. There are therefore 14 half rows, each half row has to be balanced separately, thus the center connector.

Roger

[zap mc]

I am looking at getting the shrink wrap so that once it is apart and you have eliminated or changed the duff cells you can just shrink wrap it again. I can get the Molicell cells if required, maybe we should have a group buy? $7.50 per cell. (old style ones)

I have not separated a row for fear of not getting it back together again until i had the right gear to reassemble it.

Why does the row have to be balanced each half row?

P.S.
The fact that they are configured in half rows would explain why some rows go down to 4V which would indicate that half a row is down. So if you could identify two duff half rows and eliminate them you could make a good row out of two duff 4v rows

[sylvanascent]

I'll let you go first! Take pictures and post the procedure if you figure out a way to do it, and a source for the shrink wrap. I'm too scared to try...

I might have some good cells in the other pack that went bad and I took apart. I gave the pack to a local RCer for his planes, but haven't heard any results.

Think of the pack as being 14 cells in series. Anytime you have lithium cells in series, you have to balance them from time to time, they are not like lead-acid that self balance by giving off hydrogen when overcharged. Each of the 7 "banks" are really two "half-banks" in series, like two cells in series. This is why there is a connector to the middle of each half bank that goes to the BMS.

[zap mc]

you should get the pack back and examine the rows now you know what to look for
i would buy any good rows off you

[sylvanascent]

I'll do it.