Headway battery problems

D

darkshirikens

10 W
Joined
Jun 10, 2010
Messages
91
Location
Pennslyvania
ive had this battery for a year and 3 months now and been having problems with it almost every since i got it if it was a Bms "When i used the signalabs" issue it was a battery issue when my other battery cells were 3.20 -3.13 at the highest and the lowest was 2.15-2.60 and i was getting help from the vendor to remedy the issue getting cells replaced and all but i think the signalabs killed the battery cells im having problems with and the vendor now ignores me so im stuck im thinking about just getting rid of the pack or ride it to the two bad cells die or give myself i nice light show.

I'm really regretting my investment and i dont know where to source any 12ah Headways in the U.S except where i bought them anyone know where i can source the 12ah cell in the U.S

Im running a Crystalyte 5305 with a 40a controller for those who wondering

Also my pack was supposed to be a 72v 24ah pack but im not even getting 10 ah out of it
 
why would you think the signalab BMS killed the cells?

did you balance all the cells to each other by shorting them all together in parallel initially before you built the pack up?

did the imbalance begin after you had used the pack for awhile and then it went out of balance?

did you use another BMS after you decided the signalab was damaging the pack?

do you have a history of recorded voltages of the pack while it was charging. how does it balance now compared to the voltages you were seeing initially?
 
well i dont think the vendor i bought it from would give me bad cells and no i never shorted the pack
i did do series and the one or the bms 2 mosfets blew but i followed the diagram to hook them up to series them at first the were 2 36v 50/100a bms but i switched to 72v signalabs and some didn't works straight out the box or worked for 2 miles and stranded me and i do believe if a bms isnt hooked up properly the wont work at all am i correct ? Yes i have records i do it after a ride if it shuts down too early with the number of the cell that cut me off. most of my cells balance very well between 3.67- 3.58 except the last few cells i drop in but i presume that they will balance out soon i have 2 they are both at 3.36 and when they charge they get as high as 3.47 the 2 that are giving me grief are battery 14 and 24 they stop Bms from balancing they always cut off the bms while the rest of the pack is at 3.27 -3.30 and yes i use a different bms and ive been riding it for months now after the other one two channels on the bms stopped working but this one is working real nicely i haven't had a problem with the other cells some been in there since the beginning while most of the cells been traded out due to them drop badly under load and shutting the bms off worse than my problem now
 
Clearly nothing could have been your fault :roll:

Mabye I'm being an ass, I admit I had a hard time following just what you did. FWIW, there is an inevitable dud rate with any brand. At one point people were using the term deadways, so I gather that a few duds was somewhat common. You have a big pile of cells there, so your % of duds = more cells in the pack that underperform compared to the others.

Your best bet could be somthing like this. Buy enough replacement cells to get you back up to speed. Then explore various battery management strategies. One option might be a good Hyperion charger. The idea is to leave the balancing part of the operation at home rather than carry it around. Then ride using a CA and perhaps some cellogs to monitor voltages on the road. I don't think you should need amp limiting with 24 ah of headways. At 5c, you just need to keep it under 120 amps.

Keep your dod lighter, so the batteries don't croak out on you, or just get so unbalanced every cycle.

Pensylvania is notorious for steep hills, no doubt why you got the slow motor. How much weight are you hauling? Batteries hate big amp spikes, even 30 c lipo hates it compared to a steady discharge rate.
 
i will ask again. why do you think the signalab BMS has damaged your pack?

did this problem you are now talking about begin when you decided to merge the two 36V packs into one 72V pack?

did it start before you bot a 72V BMS and you were using it without a BMS? or you had two 36V signalab BMSs on two separate 36V headway packs and then you merged them with a 72V headway BMS?

can you kinda get us closer to what has really happened? is this why the vendor gave up on communicating? or did you demand he replace the batteries after you modified it and it failed and he said no?
 
Dnmun ,
Ive never ran without a bms ive done my research lifepo4 needs a bms. I honestly dont think nothing was wrong with the cells beforehand until i tried the 72v signalabs bms some came out of the box with issues or if after i hook it up and ride the bms would cut off and i get one or two leds that light up.
I will try to get you closer, When i started having problems everything was fine i got cells replaced ,signalabs 72v bms replaced but they kept on failing and i know for a fact i dint hook up anything wrong im too careful for that i even number my ring terminals, As time went on the vendor stopped selling the signalabs due to high failure rates even the ones he had put together himself and replaced cells for other customers . Last year i forget exactly when but after he had replaced both of my two 72v bms i got 2 battery cells to replace the ones that weren't acting right and all was good the service i had got from the vendor was great. The vendor even gave me a single cell charger to review and keep cause he knew i needed one and it was around christmas . I say about January of this year i had at least a box that had 13 cells dead or dying so there was no way i could use the other 72v pack and when ever a cell fails in the pack i was using i used cells from the second pack i owned just so i can ride and now i have no spares so im stuck.
 
velias said:
It's hard to read posts with no punctuation.
At least use a period at the end of a sentence.
Click to expand...

Sorry about that hope the next on is a bit clearer to understand!
 
dogman said:
Clearly nothing could have been your fault :roll:

Mabye I'm being an ass, I admit I had a hard time following just what you did. FWIW, there is an inevitable dud rate with any brand. At one point people were using the term deadways, so I gather that a few duds was somewhat common. You have a big pile of cells there, so your % of duds = more cells in the pack that underperform compared to the others.

Your best bet could be somthing like this. Buy enough replacement cells to get you back up to speed. Then explore various battery management strategies. One option might be a good Hyperion charger. The idea is to leave the balancing part of the operation at home rather than carry it around. Then ride using a CA and perhaps some cellogs to monitor voltages on the road. I don't think you should need amp limiting with 24 ah of headways. At 5c, you just need to keep it under 120 amps.

Keep your dod lighter, so the batteries don't croak out on you, or just get so unbalanced every cycle.

Pensylvania is notorious for steep hills, no doubt why you got the slow motor. How much weight are you hauling? Batteries hate big amp spikes, even 30 c lipo hates it compared to a steady discharge rate.
Click to expand...

Nah Your not being an ass its just a bit incoherent lol, I need to source some 12ah cells so i can rebuild and i think the bms im running now is fine even though the other failed on me but im always looking for a new affordable solution for a bms, I do a short trips of under 8 miles each way that would be a little over 15 miles when i go out that day also i peddle during most of the ride but i charge at each destination i have range anxiety due to the cells acting up.

P.A do have some nasty hills I did my homework when i choose my motor cause there's no way i want to go up a hill that's steep and then roll backward cause it doesn't have enough torque i usually try to avoid the hills if i can but if i want i got the torque to climb and i peddle , The only thing in hauling is my fat ass and back pack and whatever i need to do a repair on the road so about 380 for me and 5-7 pounds for everything else that i carry in the back pack, like when i ride i don't really ride that fast i might average at 12-15 mph then if i get to and area that i know traffic is crazy or they wont care to run you over then i might hit full throttle but i peddle till the motor gets up to full speed then i cant peddle no more
 
circuit said:
To me it looks like a faulty/poorly chosen charger, that does not charge up to required voltage.
Click to expand...

I don't think its the charger cause the cells the been in my pack the longest read within .01 of each other when charging the highest the whole pack voltage i seen on charging was 86.7 and it shuts off due to the Bms reaching its HVC for the cells that are messed up they reach 3.9v
 
It is too bad there is not a balance charger for 16S but surely you could get one for 8S an parallel the two batteries to charge. IC57 makes some neat harnasses that allow easy peasy connection for series to parallel with no KFF. My understanding is that Headways are a bit finicky about balance situations and really need to be balanced regularly. I've only had 1 Signalab BMS fail but it was no a 48 volt Ping pack and I lost some cells. I rebuilt it to 36 volts with a new BMS also form Ping and it has worked fine for over 2 years now.
OtherDoc
 
i think you woulda been ok if you had shorted them all together initially so they would start out in balance.

the signalab v2 BMS has only 60mA of shunt current and you musta been on HVC all the time too since you said it only had two leds lit. and those were pegged on HVC.

just a list of cell voltages back then while it was on the charger and you might have been ok long before you decided you had all these dead cells. every time i try to get people to list up the cell voltages while charging they seem to just vanish.

it would be useful if there were numbers for this too so we could help.
 
Also as dnmun and other experts have mentioned you can use a single cell charger to try to recover individual cells. I've had some drained to 0 volts and they lived to charge again. You can also stick a resistor on the high cells to let the others catch upduring charging. Just a few more possibilities but you really do need to check and list the cell voltages during charge as has been suggested. It might save some money and hassle.
otherDoc
 
darkshirikens said:
circuit said:
To me it looks like a faulty/poorly chosen charger, that does not charge up to required voltage.
Click to expand...

I don't think its the charger cause the cells the been in my pack the longest read within .01 of each other when charging the highest the whole pack voltage i seen on charging was 86.7 and it shuts off due to the Bms reaching its HVC for the cells that are messed up they reach 3.9v
Click to expand...
A cell at 3.9 is not messed up... it is merely filled up. Manually balancing one cell at time would be the first order of buisness in my opinion also. And i suggest you remove the BMS while you do it. Once you have achieved that, then you may be able to better observe what your cells, BMS(s), and charging system are doing or not doing as the case may be.

When i have had to drain down a cell or two I have used a halogen auto head lamp which typically runs around 2 or 3 amps on a 3 volt cell. Sometimes it is faster to drain a few cells than topping of the remainder of the cells in the pack.
 
since these are the headways, it is likely all the cells are still good. you said you have a bunch set aside because they are dead. did you charge them up and then they discharged by themselves down to less than 2V?

i have several headway 24S BMS here if you wanna try to build a pack up using them since it sounds like you have 48 cells to work with.

can you group them in lots of equal voltage, then wire them together with a bare copper wire under the screws so they are parallel together at the same voltage, then put them on the single cell charger and charge them up to the same voltage as the rest of the fully charged cells. then when they are equal, short all of the cells together so they all are at the same voltage.

then with all these cells balanced, rebuild your pack, starting with all the cells at the same voltage from being shorted, and then charge the entire pack up together with the bulk charger under the BMS. that should give you a close enuff start to get them all to balance.
 
This is the resting voltage after a charge this is when i had the 72v signalabs this is the original pack i put together
1# 3.30
2# 3.30
3# 3.30
4# 3.30
5# 3.30
6# 3.30
7# 3.30
8# 3.26
9# 3.30
10# 3.30
11# 3.31
12# 3.43
13# 3.30
14# 3.30
15# 3.30
16# 3.30
17# 3.30
18# 3.30
19# 3.45
20# 3.30
21# 3.30
22# 3.30
23# 3.30
24# 3.33

The first Bms shut off i had was battery #8 which triggered LVC at 2.5v
and then it things fell apart from there got 4 more 72v bms and one after the other failed, Then after that it was a while before i got the Bms i have now that actually works but even so i hook then new Bms i have the cells started to die here is the same pack after a charge and a few laps around my neighborhood and it was sitting for about 2 weeks below

1# 3.50
2# 3.25
3# 3.35
4# 3.39
5# 3.51
6# 3.35
7# 2.48
8# 0.84
9# 3.45
10#1.47
11# 2.5
12#3.15
13# 3.47
14# 3.5
15# 3.5
16# 0.77
17# 3.31
18# 3.5
19# 3.26
20# 3.35
21# 3.31
22# 3.23
23# 1.10
24# 3.32
Now with the battery pack i assume the the ones above 3v with ultimately balance eventually for the ones that are 2v and some might be able to charge them up and they might be ok after a few more cycles but the other ones that are below 2v might be damaged and will have to be replaced, However i still had 24 untested cells from the second pack that had a signalab bms on them and me as i am i wanted to sort of the first battery pack problems first before i began putting the other cells together to for the 2nd battery pack.

So i while i was trying finish up the one battery pack i was checking on the 24 individual cell the majority was 3.31 which is good, i had some that were 3.26-3.29 which is from my understanding is nominal voltage for lifepo4 so i didn't worry about them and checked voltage monthly.
 
how long have the cells below 1V been sitting like that? take all of the cells below 2.5V and wire them together in parallel and put them on together on the single cell charger and charge them up to 3.3V where most of the other cells are.

while charging those up connect all the cells around 3.3V together and wire them together in parallel so they are all the same voltage and when the other low cells get up top that voltage then wire them all together in parallel and keep charging them all together in parallel.

as the voltage rises of this conglomerated group of cells all wired together, then attach other cells to the mass as the voltage rises to match the higher cells. keep combining them until you have all of them charging together on the single cell charger. all 48.

you can use small wire, even steel bailing wire, it doesn't have to be much in thickness, you just wanna get them all to the same point in voltage.

when you have charged the mass up to about 3.65V then you can disconnect all of them on one end. leave the other end wired up with all the cells tied together. maybe even wrap a string around it so all the cylinders are standing on end with the positive end up. then watch all of them as they lose surface charge and the voltage drops. follow that for several days until you can see them segregating into those that drain down fast and those that drain down slowly. you can clip the black voltmeter probe to the wire connecting all the negative ends together and then just probe the tops or positive ends of all the cells to measure each one.

that is one way to start, kinda the only way unless you have the fancy internal resistance measuring machines.
 
The cells that were under 2v they sat like that for a month or so till i got the single cell charger but they were taken out of the pack and replaced with cells from the cells i had on hand.

i know how to series but i never paralleled at cell level before and the the only way i know i can do is the way i only seen or read about but that will be too time consuming with all the wires put together, so my question is how would i assemble them with buss bars i know the bottom has to have the all the parallel bars at the bottom so woul i add a single buss bar at the top and continue using the parallel bars for the rest of the top till i a have like 2 cells without a buss and put a single buss there too ?

LOL a drawing or pic with both side would be better than i tried to explain how i thought to do it
 
you don't need buss bars, there is no current, you just want to get the voltages of the cells all at the same point. all of them.

the size or type of wire is unimportant. just wrap them under the screw.

stand them on end together in tight packing with a string or band around all of them to hold them together, then run the wire under screw heads, tighten them all together then turn upside down and do the other end so they are all joined in parallel.
 
you don't wanna do anything but get all your cells to the same voltage. you have to do this first so you can then watch the cells and try to isolate a group of cells that will be useful to build up a pack from. don't worry about sense wires.

like i said, stand them all up with the same polarity on the end, tie it into a close packed bundle, then run a wire under the heads of all the screws, like in a spiral going from inside to outside with the wire connecting all the cells. then since the bundle is wrapped around the outside, flip it upside down and connect all the terminals together on the other end.

if there are too many, make two bundles and then short the two bundles together with a wire to each end. you wanna get them all to the exact same voltage and the only way to do it is by shorting them together in parallel.

you start with the low cells and drag them up to the same voltage as the majority of the cells because you don't want there to be a voltage difference between them when you connect them together. like i said steel wire is fine, even better than copper because you want there to be resistance to the flow of current when the voltage of the groups is different. you can even use a resistor to connect the groups together initially to reduce the current flow and sparking when you combine them.
 
I'd start by looking at the cells in #8. If they are self discharging much chuck em. Then follow the above for the remaining cells.
 
7,8,10,11,16,23 all need charged right away, but when they are so low they immediately jump to about 2.7V and then start slowly climbing. so that is a way to start charging all of these up. make these the middle of the spiral and have them on the charger as you add the next cells up in voltage from the lots.

you could even do this by making the initial bundle of these 6 cells, with wires to the top and bottom. tie them into the central bundle, then add more cells around the perimeter of those, and encircle those new cells with another band and tie the top terminals together through the wire. but if you were assembling these bunches on top for a metal sheet then you would only need to be wiring up the tops initially and the metal sheet, like an aluminum pie plate or cookie sheet, would make the other connection at the bottom of the cell. build up another layer, then when it gets too big, flip it over and make the connections with the wire on the other end.

you just wanna get all the cells tied together in parallel and charging up to the same voltage together.

this is only so you can eventually get them all charged so you can disconnect them from each other on the one end again and let them drain down at their own rate so we can find a group of cells that you can use to build a new pack from.

trying to estimate the internal resistance would come next, after we can select a group that doesn't drain down immediately.

we should be able to make a battery work for you though, maybe even isolate the bad cells, buy some replacements and make two packs or double this one up in width.
 
You must log in or register to reply here.

Similar threads

D
9bot g30p/xiaomi 365pro parts mix n match
Replies
1
Views
498
pwd
pwd
FuzzyWuzzy
Wiring connectors to custom built battery
Replies
1
Views
164
gromike
G
J
Li-Ion Battery Pack Building Techniques
Replies
5
Views
944
amberwolf
amberwolf
M
    • Like
DIY Electric Moped Build
Replies
2
Views
275
DaLanMan
DaLanMan
M
Question about a revived lithium ion battery pack.
Replies
6
Views
655
MorganCMY
M
Back
Top