lipo puffed or not really?

[hyrulejedi86]

I have a couple lipos that feel like they have a little tiny bit of gas between the cell and the wrapper. If you look at the lipo sideways you can't but barely see what looks like there might be puffing but when you squeeze the battery a little bit it isn't just flat and hard there is a little bit of depressability. Its really hard to describe I hope others have seen this but it seems to happen spontaneously on a couple of my turnigy lipos and I was wondering what it is or if it's a sign the lipos dying?

[785boats]

I've got a couple of packs that do that. I don't consider them puffed. When they cool down they are hard again. They still take on a full charge & they still have plenty of punch.
They are a couple of years old & still going ok.
Paul.

[hyrulejedi86]

That's good to know because I have been able to give them a full charge and they act normal. I just wasn't sure if I should be worried or not.

Thanks 785boats

[d3lap]

I think its just normal as the cell looses voltage...

[Steven Vaccaro]

I've also seen this. Not sure why.

[785boats]

Well I managed to really puff a pack today. I ran it for too long. I'm really pissed off at myself because I know so much better. It was one of the old Turnigy packs I talked about in my previous post. A 5800mah 25C pack. It was puffed to about 1/4" each side & very squishy, and pretty warm, but not overly hot. It only had 9% capacity left.
It worried me enough to put it on the brick walkway out in the open for 1/2 an hour for it to cool down. It then went into the Ammo box for storage.
That was yesterday, and this morning when I checked it out it was back to it's normal size & hardness.
I'll keep a close eye on it over the next few charges & runs in the boats.
Cheers.
Paul.

[hyrulejedi86]

I've seen a real puff once myself at the local club, a new guy had some pack I can't remember what type and ran it too hard.

[Pete32200]

My Turnigy Nano-Tech 4s packs Puff up and heat up every time I run them, I have been anticipating their demise but they just keep going and going

[Paul Susbauer]

If they're puffing when warm, but then get hard again when they cool down, this is an indication that the manufacturer is using lower quality materials. They will work, but will heat up more than a better quality cell with similar ratings.

Paul Susbauer
Venom Group International

[785boats]

Pete.
If your packs puff & heat up every time you use them then it's possible that they are under size & C rating for your installation or you are running them for too long & over discharging them.
Cheers.
Paul.

[G-UNIT]

Yea I have some zippy flight max that have been puffing lately, 5000mh 40-50burst but when they cool down they go back to normal, they never did it before but they are getting on with age but still running fine, once they even got to 160 degrees and still take a full charge, although when charging they only take about 4.14 volts per cell versis 4.18-4.19 like they use to.

[Boaterguy]

I even shorted a pack out once, oops.. it went out on the patio for an hour and I sat close by with an extinguisher. it puffed a little and stayed that way but it still runs fine.

[785boats]

That pack that I overdischarged has now lost a cell after a few more cycles through it.
Shows 0.28V. It read 3.7V like the other cells in the pack after the last run, but it's lost the voltage over the last 4 days.
But here's the funny thing. I use the Hyperion voltage tester before charging to see what the pack condition is like & it read the following
Cell#1...4.612
Cell#2...3.698
Cell#3...3.711
Cell#4...4.624
I knew that couldn't be right so I checked each cell with the multi meter & got this.
Cell#1...3.71
Cell#2...3.72
Cell#3...3.72
Cell#4...0.28
Any ideas on why the Hyperion tester gave such strange readings anyone?
Seems that if you get a high voltage reading on a cell or two in a depleted battery, there might be a problem with a cell.
Anyhow, I'll remove the cell & turn it into a 3s pack & use it in my scale boats that only draw between 15 & 30 Amps.
I need another 3s pack anyway.
Cheers.
Paul.