De-Puffing Turnigy Lipo Cells
- Thread starter AussieJester
- Start date
TheBeastie
1 MW
Thought I would post my current setup for my lipos to deal with puffing problems. I don't know about other people but I don't think its some kind of magical mystery that the cells that always tend to go bad and puff the most are the ones on the outer sides of the pack.
I am now placing my lipos in these cases that are an ultra tight fit for 6S turnigy lipo packs (50mm). I got this idea/box from some other poster on here, I forget who.
For some of my packs are getting puffy again and I had to put my foot down plus my body weight on the lid of the box to put the screws in.
http://www.ebay.com.au/sch/i.html?_odkw=Box+187+118+57&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.XAluminium+Box+187+118+57&_nkw=Aluminium+Box+187+118+57&_sacat=0
I am now placing my lipos in these cases that are an ultra tight fit for 6S turnigy lipo packs (50mm). I got this idea/box from some other poster on here, I forget who.
For some of my packs are getting puffy again and I had to put my foot down plus my body weight on the lid of the box to put the screws in.
http://www.ebay.com.au/sch/i.html?_odkw=Box+187+118+57&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.XAluminium+Box+187+118+57&_nkw=Aluminium+Box+187+118+57&_sacat=0
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Allex
100 MW
I still do not understand what you achieve with this box? I f they are puffed the only way to release pressure from the cells is to make a cut in it.
The puffing came back. More noticeable after discharge. I hooked up a voltmeter to the cells. You can watch the voltage rise just pinching it with your fingers. :lol: I clamped them down again with authority this time. These type of batteries are a joke.
izeman
1 GW
i will never understand why someone will invest time to make a dangerous chemistry even more dangerous. rc lipo is known to be handled with caution and is a great high power capable chemistry. but it's also known for doing some bad things if you don't treat it with respect. overcharging and physical damage. so a cell puffs, and you can't look inside. but probably something bad already happened to it's physical structure. and you ignore that just to safe some $/€ ??? a cell that's puffed once is worthless and will never deliver pull amps.
Just remember that CyanoAcrylates are generally water-insoluble....but might dissolve in some of the stuff used n batteries.
nutnspecial
10 MW
Thanks for this thread!
I have been running 20s in 1p and 2p with 2 modular packs. Mostly bulk charging. There is 2x6s and 2x4s in each modular string.
The 4s's have always been a little weird, and I've kept an eye on two packs inparticular, for one stray cell in each. These tend to bottom out before the rest. I even did bottom them out, but clamped and recharged very slowly (less than 1% c-rate) and they've been fine.
I did a check (and visual) of all packs 2day, and found a 4s pack that previously had no problems had puffed. The voltages were on par with the rest of the pack and each other. -about 3.77v. There was no way they were over charged or discharged I can imagine. I was last running in 2p, so even continuous discharge was like 6c.
So what else can cause a puffed cell? The ONLY thing I can think of is that I've used the same 14a mw charger for a single parallel pack a few times lately. Meaning I was charging @ about 2.5c. These are turnigy 5.8ah 25-35c batteries. 1c charge I believe. Has anybody had a puff occur that way?
Like I said, cells (particularly in this pack) have ALWAYS been kept 4.15-3.55v, and have been protected against any impact.
Just trying to figure out why it could happen, then if to 'repair' or eliminate the cell.
Thanks!
I have been running 20s in 1p and 2p with 2 modular packs. Mostly bulk charging. There is 2x6s and 2x4s in each modular string.
The 4s's have always been a little weird, and I've kept an eye on two packs inparticular, for one stray cell in each. These tend to bottom out before the rest. I even did bottom them out, but clamped and recharged very slowly (less than 1% c-rate) and they've been fine.
I did a check (and visual) of all packs 2day, and found a 4s pack that previously had no problems had puffed. The voltages were on par with the rest of the pack and each other. -about 3.77v. There was no way they were over charged or discharged I can imagine. I was last running in 2p, so even continuous discharge was like 6c.
So what else can cause a puffed cell? The ONLY thing I can think of is that I've used the same 14a mw charger for a single parallel pack a few times lately. Meaning I was charging @ about 2.5c. These are turnigy 5.8ah 25-35c batteries. 1c charge I believe. Has anybody had a puff occur that way?
Like I said, cells (particularly in this pack) have ALWAYS been kept 4.15-3.55v, and have been protected against any impact.
Just trying to figure out why it could happen, then if to 'repair' or eliminate the cell.
Thanks!
nutnspecial
10 MW
GUYS, are you aware of any other way to depuff cells?
I haven't heard/read anything, but may have stumbled across somthing.
DISCLAIMER : I DON"T KNOW WHAT THE HLL I"M DOING!
I wanted to empty the 4s pack with one puffed cell before stripping it, and possibly doing this pierce method, or cutting out the cell. Like I said, all 4 cell voltages were close, and didn't get drawn too low or overcharged. 3.75 x3 and #2 was 3.68.
I tried a heater element, but I guess cuz it's designed for 110 ac, the 15v dc wasn't allowing much current. It took like 5 minutes to warm at all, and did nothing to the pack level. (maybe -.01v)
I decided to start playing with 10ft 10gauge copper, and 2ft 2 gauge aluminum. As expected, it was basically a welder- there wasn't enough resistance, and after one second the wire was REALLY hot.
As I was messing with the wires, I just happened to check the pack. It was warm of course, but GUESS WHAT?
The hard puffiness was gone! I then clamped it, and now there is no puffiness.
What happened? I didn't hear a hiss, and don't think there was a rupture? Could a near dead short somehow recondense the gas pressure?
I have no idea, this is new to me.
I still don't know what could have caused the puff in the first place- it's either simply a crap battery showing itself after 20ish cycles, or because of charging around 2.5c when I'm only running one parallel string.
I haven't heard/read anything, but may have stumbled across somthing.
DISCLAIMER : I DON"T KNOW WHAT THE HLL I"M DOING!
I wanted to empty the 4s pack with one puffed cell before stripping it, and possibly doing this pierce method, or cutting out the cell. Like I said, all 4 cell voltages were close, and didn't get drawn too low or overcharged. 3.75 x3 and #2 was 3.68.
I tried a heater element, but I guess cuz it's designed for 110 ac, the 15v dc wasn't allowing much current. It took like 5 minutes to warm at all, and did nothing to the pack level. (maybe -.01v)
I decided to start playing with 10ft 10gauge copper, and 2ft 2 gauge aluminum. As expected, it was basically a welder- there wasn't enough resistance, and after one second the wire was REALLY hot.
As I was messing with the wires, I just happened to check the pack. It was warm of course, but GUESS WHAT?
The hard puffiness was gone! I then clamped it, and now there is no puffiness.
What happened? I didn't hear a hiss, and don't think there was a rupture? Could a near dead short somehow recondense the gas pressure?
I have no idea, this is new to me.
I still don't know what could have caused the puff in the first place- it's either simply a crap battery showing itself after 20ish cycles, or because of charging around 2.5c when I'm only running one parallel string.
izeman
1 GW
I never repair cells. Once they show any abnormalities i dump them. Better be safe than sorry.
nutnspecial
10 MW
Certainly good advice, they are dangerous fuel for sure. I need to evaluate what has happened before I decide.
[youtube]yreU3vrN_5o[/youtube]
I'm looking for input on what happened here. Why did it depuff?
Also why would it puff in the first place assuming no overcharge or discharge.
Just the couple times I charged 2.5c from about 3.7v/cell?
Many of you have been running lipo for years. Is there a concensus here?
[youtube]yreU3vrN_5o[/youtube]
I'm looking for input on what happened here. Why did it depuff?
Also why would it puff in the first place assuming no overcharge or discharge.
Just the couple times I charged 2.5c from about 3.7v/cell?
Many of you have been running lipo for years. Is there a concensus here?
nutnspecial
10 MW
So has anybody had a cell puff, and depuffed in this manor? ^^^^^^
I'm curious what to expect, but so far so good.
Unwrapped that pack, charged, and rewrapped with a filament tape.
Discharge has gone fine. Balanced and not puffed.
I'm curious what to expect, but so far so good.
Unwrapped that pack, charged, and rewrapped with a filament tape.
Discharge has gone fine. Balanced and not puffed.
TheBeastie
1 MW
I always pricked my lipos, but some can just pop some how and let the gases out. I had a lifepo4 pack that was given to me for free because it was so old, it had bad cells etc but I forced charged it via a bc168 parallel charger to v3.6nutspecial said:
I then did a pack discharge test at a mere 4amps into some globes and the most outer cell was already puffy but it got super puffy and hot and then kind of farted, I never pricked it etc it just came out by it self..
For my lipo I also kind of massaged them, I have no idea if it helps but I did do that.
Once they gone this level I treated them like a grenade with its pin pulled but dud for some reason...
I got some good cycles out of them still once I did it.
I found charging them up to 3.85 and leaving them for weeks seemed to help as well in terms of giving some good power on their next cycle.. its like treating your body as it gets older, you gotta let them rest longer.. But this is also just a personal theory, no lab level testing just observation..
But I don't use lipo for my bikes any more though btw.
nutnspecial
10 MW
Thanks for the info Beastie! Lipo has been a pita, but all my issues were with the 4's while the 6's have been lovely. Bought them @ different times- the 6s actually out of season, 4s in season.
I can't say I tried massaging *eyebrow raised*, I just wanted to drain it down to dissect and/or prick it. Was surprised it depuffed with the above method.
Not sure if that was considered a dead short or not, I suppose what defines that from a standard heating element would be resistance. Either way, it seems to have taken care of the puff.
I can't say I tried massaging *eyebrow raised*, I just wanted to drain it down to dissect and/or prick it. Was surprised it depuffed with the above method.
Not sure if that was considered a dead short or not, I suppose what defines that from a standard heating element would be resistance. Either way, it seems to have taken care of the puff.
