2S pack swells after run

[ezhitz]

Running my boat yesterday a couple of my packs seem to puff up a little as if the shrink wrap was inflated with air then went back to normal after they sat.My packs never go over 120-125 f.They are Turnigy 5000mah 30c new this summer.
I think my motor might be on its way out because I seem to be using more mah now because after my 3 minutes i did draw over 4000mah out of the pack that was puffy.My hyperion charger said the pack was at 17%.The boat set-up has not changed all summer and my lvc is set at 3.2.The pack charged back up fine is this normal or should i be concerned.

[Fluid]

That's an average of 80 amps draw, not excessive for a 5000/30C pack if we believe the label. Some packs will inflate a little bit, then go back to normal do you may not have a pack problem. But without knowing the boat specifics (type, motor, prop, etc.) we can't give much more of an answer.


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[ezhitz]

Thanks fluid its in my Jae12 rigger running a feigao 7s(5196kv) X432.I posted alog from my eagle tree and a quick clip of it running.

http://www.youtube.com/watch?v=3ytcGFXHhJs

[Fluid]

In that case it is not out of line for the setup. I don't think you have a motor problem, unless the EagleTree numbers have changed significantly over the past few months. The packs are probably fine, I had some ThunderPower packs which did that but lasted for years.



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[ezhitz]

Thanks Fluid the numbers haven't changed much boat runs mid 40's and it's fun to drive so I will just drop the timer down to 2 3/4 minutes so i don't run the batteries down as much.

[Gerwin Brommer]

lvc = 3.2 ??
I would set my lvc at 3.5

[Fluid]

Setting the LVC at 3.5 volts almost guarantees that your boat will stop prematurely with either cheap packs or a high draw setup, with plenty of capacity left in the pack. I've datalogged older but still very good packs which drop to 3.4 volts at just 100 amps draw. Why would you want to set the LVC so high when damage won't occur until below 3.0 volts? Remember that the LVC is for loaded voltage, not static voltage.



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[Gerwin Brommer]

Jay.

To make sure he makes short runs :-)

btw : Ezhits : running 2S1P or 2S2P ?

[ezhitz]

I'm running 2S1P

[Steven Vaccaro]

Some packs will inflate a little bit, then go back to normal do you may not have a pack problem.


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This is interesting. I was going to post about this and forgot. My Hyperion start out a nice flat top side, and than puff a tad, then go flat. I was worried. Pat at RcLipo said that any puffing is bad. What should I do?

[H2OCamel]

I have never had problems with puffing until I got some Hyperions.....i had been buying the enderland lipos pat had on sale and still haven't had a single issue with them.

[driftah]

puffing indicates a problem in the battery,poosibly due to an over amp draw occurring or otherwise.I had 2 smc high dollar 2s 50c hardcases that split.. and back they went they are always a risk...always

[Brushless55]

I would do a balance of the packs to make sure they are topped off before the run, and don't store them charged

[Gerwin Brommer]

Do you pre-heat your packs before running them ?

[ezhitz]

I use a hyperion charger that balances each time i charge.
No i don't pre-heat the packs but that was the first time they did that.

[sailr]

The shrink wrap is so tight on some packs that the air heats up inside and puffs out the wrap only. When it cools, it goes back down. Not a battery problem. I have actually 'carefully' punctured just the wrap before and watched it go down immediately. This was not on a hyperion as I haven't had a hyperion puff.

There is no PERFECT battery out there. Regardless of the brand or price they are all susceptible to failure either through improper charging, storage, or usage...OR...simply a bad pack! The cheaper the packs, the more often this is likely.

In my opinion you are using the BEST packs out there.

This is interesting. I was going to post about this and forgot. My Hyperion start out a nice flat top side, and than puff a tad, then go flat. I was worried. Pat at RcLipo said that any puffing is bad. What should I do?

[Steven Vaccaro]

Thanks for the info Jim. I will look at that.

I do not preheat. But do balance charge on each and every charge cycle.

[sailr]

No need to preheat in Florida!

[SweetZ28]

Reason why they start to puff is due to temps 140 deg or greater or if you are over draining the lipo and it can't supply the amp draw ... you need higher C rated packs.... they puff up because the chemicals inside break down to a kind of liquid that's why they get soft so a soft lipo is a bad lipo a lipo should always feel hard a bad one you can smush it around a bit and it feels puffy.