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My bicycle motor works 72v 6p is acting up after 2 years

999zip999

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Jan 10, 2010
Messages
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Location
Dana Point So. Cal
2 years ago I bought a 72 volt 24 ah pack of Samsung 21700 40t 30amp cell pack. When I first got it it wasn't fully charge on any one of my 72v chargers, only 81.2v. yes I checked the output of my two other 72 volt chargers one's a grin. So I sent it back to Matt Buzra ( I'll have to get the name right ) and he said he replaced a six-piece set and then put a Bluetooth BMS on. It charged but I only got 19.5ah out of it using it at 80 amps for a little bit but 60 amps is what I used at.
3 months ago battery is acting a little weird so I took it out looked at it and he just took solder wick and solder in the 6p in there. Got it back together and the BMS is working again that was the reason I took it apart.
Now my bikes cutting out early and I put a new bluetooth app so I can read the cell level the one with the blue elephant 3.1 doesn't show sell level monitoring I'll see the pic of the battery with the solder which first.


 
I hope this is a screenshot of my Bluetooth BMS.
I did it
Number nine and number 18 are very low.
I didn't want to charge him up to I got the cell level working on my Bluetooth BMS so I could send you a pic.
I guess I could plug it into charge because nothing went below 2.8 volt but I think those two parallel groups are done for.
I doubt if they're even worth replacing as this was supposed to be made out of Samsung 40t 21700 cells but they seem counterfeit to me for $1,200.
 
With bad welds, those two groups could be 5P instead of 6P. Looks like nickel on copper. I have no experience with that, but know it takes a powerful/consistent welder.

I would give the BT BMS a chance to balance it, unless your Satiator can be set accurately between 4.20 and 3.60 volts. If it's that precise, I'd manually balance with the Satiator instead. After that, run it down past 40% and see how the balance looks.
 
Would have been nice to use big cells with screw terminals, yeah?
 
you could try to manually balance them and then try to rejuvenate them if you click on my
desulfate 30q/40t thread in my signature to see what im talking about
 
Yes I will hook up the satirator and charge with that as opposed to my meanwells at 12amps.

Yes I love one big cell for may ah. And all may past pack are big pouch cells.
Goat man your sig has disappeared ? But you are still here. Have a link.
Yes 20s 6p of Samsung 40t 35amp 4,000 mah cell. And only 128 cycles something is wrong other than that 6p of wicked soldered cells.
The cell level on the BT 3.1 little elephant app. Never worked so two months later found an app that shows the cell level last week. And I found my controller cutting out and the cell level showed up on my phone like that.
 
Chalo if I used screw tops it would weigh twice as much and twice the size. And wouldn't fit. I love my A123 20ah cells. Just needs to be half the size half the weight.
 
Tomorrow I'll put it on the 72 volt 5 amp startsrtor
. Because at the moment also are at 3.1 or above but if one group sells has already gone extreme low I will see it because it'll be the fastest charging so group on my bluetooth hopefully
 
I was working on putting my 13s N.E.S.E 8p pack of p42.
And was charging with the grin at 5a. So working on second bike . I looked at my phone's Bluetooth and I saw 3.71v and the low one was 3.5 01v and wasn't balancing I freaked and put a hair dryer on it to bring it down below 3.6 and then figured out this is lipo not lifepo4. So I put it back on the charger for a while but didn't get too far everything was looking good and I think the balance only comes on at 3 seven or so as I bought the pack and I'm not sure how to make the settings. And don't care at the moment I think I have to put it back on the charger get the voltage up high enough will it will start balancing I could probably put it on my 12 amp charger once I get that low cell 3.5 and the high cell 3.6v ? Then stop it when the first one reaches something like 3.8 or 3.9 and put the grin charger back on for lower amps. ???
 
heres the link
basically all you do is drain down each cell group to 2.5v to bottom balance the pack at 50 volts then charge and discharge the pack 2 times
id bottom balance your pack and switch your charger to 82 volts max (4.1v) so you dont throw the pack out of balance by trying to top balance old cells

 
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Here's a pic of my BMS okay now. At this point the balancing mechanism on my Bluetooth BMS kicks in and makes the grin charger fluctuate then turn off.
So it won't charge when the BMS is balancing. It's a big triangular battery 20s 6p I really don't want to cut it open again. All my other batteries have balance wires coming out 4s 5s 6s 7s and I can easily tap in with my through the balance wire charger. That's on all my other batteries. If I built a battery with a Bluetooth BMS I would still have four 5S balance wires coming out of a 20s pack.
 

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I'm just going to see if I can sneak up on it again with the grin charger it's at 5amp maybe after I try it and it doesn't help the lower cells come up I will sit it at one or two amps after the bouncer balances it down I think my balancer is set to bring them down to 4.12 v or something
 
thats pretty darn close to being balanced, a fully charged 40T wont stay at 4.2v, a few more balancing sessions and youll see which cell groups are the weak groups and if they are 4.12v just adjust your charger to 4.1v/group so your not overcharging those groups.
 
Si man yeah I was watching on my Bluetooth screen I let it get up to 4.25 because I understand it was the bounce or expansion at the top of the balloon whether it actually hit 4.25 hard to say but yeah I said watch the other groups I don't know where they sit in the pack if they're the water ones as being solder with hundred-watt Saturday I would hope if you use the 40 w you would have cooked the end of the cells really you would have to use a 100 watt hair iron with a sponge that you can do it. And sell it.

Sorry I had to clean that up talk to text.
 
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One is at four point eight nine volt two groups and the other is for 4.2 2 5 volt when I pull the plug on my grin. They don't interact very well together the Bluetooth BMS and the Green 72 volt charger I would have to trick things or call Justin. Ha Ha.
 
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Si adult man yeah I was watching on my Bluetooth screen I let him get up to 4.25 because I understand it was the bounce or expansion at the top of the balloon whether it actually hit 4.25 hard to say but yeah I said watch the other groups I don't know where they sit in the pack if they're the water ones as being solder with hundred-watt Saturday I would hope if you use the 40 w you would have cooked the end of the cells really you would have to use a 100 watt Saturday item with a sponge that you can do it. And sell it.
i speak your language and completely agree
 
Okay Sunday morning this is where they set my BMS too I guess I could probably set my mean Wells to our lower voltage but they charge at 12 amps which is a little racy for this battery in sick Bay.
That said I'm using the stator grin @ 84v and 4.5amp now.
 
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