Victpower battery pack after 1 year

[Spacey]

I've had one pack have a cell go puffy. Had never been used but I suspect the cell was damaged in transport as there was NO protection on it.

The positive lead has to be re connected as it is a copper lead which has been soldered to aluminium...obviously this can not work and could not have been checked. It can be attached though with stripping and rebuilding the pack which I have done.

The black stuff is just for separation and protection....and yes you will need a huge soldering iron to get through the solder without damaging the cells...

Wont be making that mistake again...FU Victpower

 

[cwah]

Why not butane soldering? It's small, doesn't take much space, it's cheaper and heat much more? And I also live in a small place so I prefer small :lol:

I think I have basically few choices now:
1. Cheapest/Easiest: I can replace the bad cells directly in this pack:
- I'll have to get a new aluminium soldering rod: http://www.ebay.co.uk/itm/ALUMINIUM-BRAZING-soldering-welding-kit-LOW-TEMP-includes-flux-/390610384574?pt=LH_DefaultDomain_3&hash=item5af23176be
- And get new cells from Victpower / OSN
- But it's going to be a pain every time I have a dud cell

2. Intermediate: I salvage all cells and replace it with a new kit from OSN/Agnisium and buy 6-8 additional spare cells

3. Most expensive: I buy a new battery from OSN power. It'll be directly with the right box and kit. If any issue I can just use my current pack cells to replace the bad cells

I'm thinking that option 2 is the most appropriate. Although Dnmum thinks option 1 is better and John thinks option 3 is better. Any agreement? :lol:

 

[dnmun]

i tried to explain what i thought you should do. every time you handle the aluminum and copper tabs and flex them they get damaged, it is impossible to unsolder the tabs and remove then and then put them in a clamping type pack kit like agnius developed. you are stuck with the size of pack you have now.

you do not have to unsolder the pouches. just get some narrow, surgical steel strength type steel scissors which will fit in between the tabs on each side of the one you have to cut and just stick the scissors in and cut the tab off and then pull the puffed pouch out. then on top of the pcb across the span where cell would previously had made the serial connection, then you would solder a wire from the solder on top of the pcb where the tab sticks out. so now the current flows for B- directly to 2- and do that to the others that have puffed up.

after you have removed the puffers and made the connections where the pouches were before, then you have to rewire the sense wire cable to get it straight, but now it will be 3 short. so you need to hack the BMS so it will then work with 17S. or 16S if you decide to cut out one of the more suspicious ones where you can already see the aluminum eaten way inside the mylar. each one of those you see should be removed.

so assume you get down to 16S, then buy a 16S BMS and sense wire cable and solder the sense wire bundle onto the pack you have left.

then charge that 16S pack up until you know it is fully charged on each cell. then discharge the battery through a watt meter and measure the charge it delivers until the first cell hits 2.1V and the BMS turns off. you have to be monitoring the cell voltage with your voltmeter while doing this so you can measure the cells that drops in voltage fastest and so you will know what the capacity of the worst cell is. then use a single cell charger and recharge just that one cell enuff to be able to continue the discharge. when the next cell hits 2.1V then record the capacity of that one, repeat until you have something close 18-19Ah capacity. then go and cut out the cells which have low capacity and make the battery shorter still until you have a pack that produces something close to the 20Ah it should. you can buy another BMS or hack down the 16S if you did not hack down the 20S BMS already. you can buy a BMS prepared to the specific number of cells you end up with if you cannot hack that one by going to this place and looking at the BMSs they have for the specific length you need :

http://www.bestekpower.com/pcmbmspcbforlifepo4batterypacks/

you really have no other options. of course it is not appropriate to junk it, but you have only one course of action to use this pack in the future. you cannot leave those bad cells in the pack like that, just cut them out and solder the connectors on like i said. i only see puffed cells like this when the cell has been over discharged or over charged, so i suspect your current BMS doesn't work either.

 

[jonescg]

Re: option 3, you will have spent $1400 on more junk battery, which might give you another year. I suspect that a new battery from the same firm (or similar firm) will be as bad or possibly worse, as the supply of B and C grade cells starts to dry up.

It's a pretty compelling case to salvage what you can on this exercise and save your coin for a decent NMC pack in time to come.

 

[docnjoj]

Hey cwah
Re: Option 1
Have you ever soldered aluminum successfully? I am not sure that anyone on E-S has, but I could be wrong.
otherDoc

 

[GSteg]

Re: option 3, you will have spent $1400 on more junk battery, which might give you another year. I suspect that a new battery from the same firm (or similar firm) will be as bad or possibly worse, as the supply of B and C grade cells starts to dry up.

I hope that's not the case as I recently bought a battery from OSN (B-grade). Been using it for my commute everyday and it's been holding up so far. Only time will tell whether I got a good one or a dud. I truly think the issue with the OP's battery is how it was put together, rather than the cells itself. I was never a fan of victpower's craftsmanship anyways. Cwah, one quick email to OSN will confirm whether they still have B-grade cells or not. Last I checked, they still had some, although supplies were dwindling down.

 

[cwah]

Dnmun, I don't want a 16s pack!! Isn't there anyway to salvage the cells? At worst I can still remove the bad cells cells? If it becomes a 16s pack I better sell it and get a new one for my required voltage???

John, where can I find decent 72v NMC pack? And what is the expected lifespan?

Doc, I've purchased it before but my iron wasn't strong enough. Don't know if that works

Gsteg, I'm considering this option. You should check your pack to inspect the cells because my one was working and somehow I only noticed lower capacity but I thought it was because of winter.
It's only when I decided to inspect the pack for sanity that I discovered this horror!!
Are your cells easy to replace?

 

[mikebikerad]

Out of 6 packs I bought from Victpower only 1 is still surviving. I had to make little clamping copper tabs for the positive terminals on all the packs.....but then I started getting one or two really bad puff cells in each pack. Luckily I put these packs on my personal bikes otherwise friends and customers would have been affected by VP too

I am confident that more cells in these packs will fail in the short term so I went completely different routes and keep these packs in my battery graveyard until I find some strange use for them. If you get some hobbyking lipo you might get failed cells but the ease and cost of replacement is #1. Good luck

 

[cwah]

Mike, what do you use now? Hobbyking batteries only?

 

[GSteg]

Gsteg, I'm considering this option. You should check your pack to inspect the cells because my one was working and somehow I only noticed lower capacity but I thought it was because of winter.
It's only when I decided to inspect the pack for sanity that I discovered this horror!!
Are your cells easy to replace?

I really don't want to open it up because I'll have no way of packing it again. If it ain't broke, I'm not fixing it.

My cells should be easy to replace. OSN used their own kit for the assembly.

 

[cwah]

But the whole point is to have a pack easy to repack lol
If it's difficult to fix, then it doesn't worth it. I was thinking the same thing with my Victpower pack... until I checked it now

 

[GSteg]

It should be easy to replace the batteries in the OSN pack. What I mean is that I don't have packaging material to put it all back. I can use duct tape and whatnot, but in its current state, it barely fits into my bag. Chances are, I won't be able to wrap it as tight and with an extra layer of tape, it definitely won't fit back into my bag.

 

[neptronix]

Just saw this thread..

Wow, what a hackjob of a battery pack. Thanks for letting the forum know about this.

 

[cwah]

I'm so unhappy to loose so much money... i don't know what to do anymore

 

[izeman]

i can understand you. but sometimes it's better to just move on and forget about the loss.
but of course i don't know about your financial situation. $700 is a lot of money, but if i think that a one week's vacation for my family of five costs more each day, i can better cope with such a loss

 

[agniusm]

I'm so unhappy to loose so much money... i don't know what to do anymore

Dont be. Get your stuff together, and start DIY on your pack. Get it apart, clean all the cells, inspect each for phisical damage, check if more cells are soft or has black spots on the edges. Cycle them at 1C, leave them for a week and check the capacity. Order missing cells with few extra, get mechanical clamping kit from OSN. Most here had to change cell or two in theyr packs from these cheap cells.

 

[cwah]

I'm so unhappy to loose so much money... i don't know what to do anymore

Dont be. Get your stuff together, and start DIY on your pack. Get it apart, clean all the cells, inspect each for phisical damage, check if more cells are soft or has black spots on the edges. Cycle them at 1C, leave them for a week and check the capacity. Order missing cells with few extra, get mechanical clamping kit from OSN. Most here had to change cell or two in theyr packs from these cheap cells.

Apparently It would damage the cell if I remove them? Can I salvage the pack or not? I'm about to get a cake butane torch to heat up the tab ultra fast and remove them.

 

[izeman]

I'm so unhappy to loose so much money... i don't know what to do anymore

Dont be. Get your stuff together, and start DIY on your pack. Get it apart, clean all the cells, inspect each for phisical damage, check if more cells are soft or has black spots on the edges. Cycle them at 1C, leave them for a week and check the capacity. Order missing cells with few extra, get mechanical clamping kit from OSN. Most here had to change cell or two in theyr packs from these cheap cells.

no. he's got to order one of your kits and do it right
afair there was a doc in the big a123 thread explaining how nasa(?) tests their cells. look it up, go through it and test every cell as agniusm said. maybe most of them are ok. also get yourself a proper bms if this one is broken. my bestechpower is great value - lot of info about them in a seperate thread as well.
heads up!

 

[agniusm]

I'm so unhappy to loose so much money... i don't know what to do anymore

Dont be. Get your stuff together, and start DIY on your pack. Get it apart, clean all the cells, inspect each for phisical damage, check if more cells are soft or has black spots on the edges. Cycle them at 1C, leave them for a week and check the capacity. Order missing cells with few extra, get mechanical clamping kit from OSN. Most here had to change cell or two in theyr packs from these cheap cells.

Apparently It would damage the cell if I remove them? Can I salvage the pack or not? I'm about to get a cake butane torch to heat up the tab ultra fast and remove them.

They were put together with heat in the first place. You have no other option left, try 200w soldering iron first.

Izeman, thanks, but I dont like to force my product to anyone, after all it is expensive and requires some labour.

 

[izeman]

I'm so unhappy to loose so much money... i don't know what to do anymore

Dont be. Get your stuff together, and start DIY on your pack. Get it apart, clean all the cells, inspect each for phisical damage, check if more cells are soft or has black spots on the edges. Cycle them at 1C, leave them for a week and check the capacity. Order missing cells with few extra, get mechanical clamping kit from OSN. Most here had to change cell or two in theyr packs from these cheap cells.

Apparently It would damage the cell if I remove them? Can I salvage the pack or not? I'm about to get a cake butane torch to heat up the tab ultra fast and remove them.

i guess dnmun said that the tabs are broken once they are soldered and bent too much. i would still try to remove the cells and see what they look like when you have them lying on the table.
do NOT forget to insolate the tabs you are not working on when desoldering the tabs. you can be as careful as you want, a single blob of solder making a short, and bad consequences can happen!

 

[cwah]

They were put together with heat in the first place. You have no other option left, try 200w soldering iron first.

Izeman, thanks, but I dont like to force my product to anyone, after all it is expensive and requires some labour.

All 200W of quality cost around 100euro. They are expensive. I've found this one for 85 euro but it's very expensive for a single use:
http://www.leboncoin.fr/bricolage/505329387.htm?ca=12_s

 

[RayGo]

+1 per izeman.

I thought I isolated all the tabs and worked carefully building my pack. I dropped my wrench while tightening a nut and of course it hit the "magic" spot. One large spark later that scared the crap out of me and my wrench now has a large melted spot on it. So be careful.

After salvaging your cells, check your remaining tab lengths. You will need 10 to 12mm of tab length in order to use either of the two OSN or agnisum packs. Anything less in tab length and you would be best off using OSN's first build kit or zappy style fold-over copper clamps or just use strips of copper or aluminum to clamp the remaining tab lengths together with appropriate sized nuts and bolts. You need to drill holes in each tab to mechanically connect the tabs to the clamps. You can then isolate each tab connection with vinyl tubing, electrical tape or whatever material you have.

If you don't have enough tab length remaining for clamping, then you have your work cut out for you. You need to be able to connect 10 or 12 gauge wires for connection to your battery and/or charger. Lots of luck with the salvaging operation.

 

[cwah]

Thanks Raygo, Now I have to find a powerful 200W iron that isn't expensive... :lol: I'm trying to find some second hand otherwise it's going to cost me hundred..

Also, I was discussing again with Victpower to buy new cells and I've got the answer:
"
Me: Apparently you don't have much cells in stock, and the remaining one are bad quality.
Is it true?

Victpower: It's not true. We have 60,000pcs in stock, now the cells 3.2v, real capacity is 19ah,normal is 20ah.
But this is no logo of A123, and the tabs not original, but we test is good. And price is low.
A123 with original tabs no stock in the all world.if have, will US$27 per one.
Compare to 14usd and 27usd, the no logo one is good.
U can test some sample to test.
Thanks
"

Ahah, wow. I was thinking to buy real A123 cells. Hopefully they're not going to trick me twice :lol:

 

[999zip999]

Cwash you only need a 85w solder iron but bigger the better. Put the battery upside down when you heat up the tap area. Once hot hold the pack in your hands and throw th the heated solder down or off just on a plywood board and let it burn. Just get rid of the solder and it will only char the board must be done close to bucket of water. I will ask my friend Nancy at osn to see if she can help. the old bolt together and how many cells.

I would save and buy a good working battery and keep this as a repair hobby battery. Sorry Bro.
Victpower has always been a shit hole. I fill lucky with my 25 cells one with high I.R. and replaced. It works as a e-bike battery @ 30-40 amps. Yes it's just for a e-bike and not the death bike at 400 amp shit.
What are you located ? can't help if You can't drive over.

 

[GSteg]

Here is a response from OSN:

Hello,
Good evening.
About the A123 batteries, yes you are right, there are less suppliers have the stock now, except us.
But we also do not have much stock(about 1000PCS).^_^

Best regards,
Nancy

Grab them while you can.