When do you retire your LIPO?
 

Have some Lipo's around a year and so old with some 40 to 60 cycles on them, the punch is not as much compared to a new one, moreover they are not charging to their full capacity anymore as i suspect the voltage drop is substantial and the LVC is kicking in before the rated mah are used up. and lastly they swell a bit and get hot to 50 - 53 deg C after some hard bashing.

Time to retire them? any other uses? am i compromising the ESC?
Is 50 cycles on average enough, or should i be getting more? I heard that cycles are in the hundreds before having the Lipo depleted.

I measured their internal Resistance using this formula:
IR of battery = V drop * R / (V drop + V no load)
Using a Extech EX 330, should be quite accurate.
Getting IR of 25 to 45 milli ohms per cell, checked my new Lipos that arrived got around 35 milli ohms ?! but they are quite punchy, i get to bash hard and use all the 5000 mah.

Should I be measuring the IR when they are fully charged at 4.2 v per cell or when they are used up?

I know these are a lot of questions but would appreciate some feed back, ideas, experience in this issue.

Guess I was too scientific and over analyzing?!
I guess then when they puff or swell just dispose of them...

Have read a lot of the Gens Ace Lipos, any recommendations compared to Turnigys?

gens ace are great, and I usually have good luck with turnigy too. Some of failed a little early on me, but I don't mind too often, I could be paying 4-5X the price for lipos.

You run your batteries down to LVC all the time? That could be affecting their lifespan if is set too low. I run mine at 3.3 or 3.4V/cell. And if you stop before that your batteries will be all the more happy.

As far as your IR concerns, I have no idea really. Maybe try different resistances and average the IR. Not even sure if the equation is correct, but the dimensional analysis returns ohms, so at least it's the right units! I know some chargers will tell you the IR of packs.

Thanks for the info brainiator, would take the Gens Ace into consideration on my next purchase.
As you have, I also set my LVC at 3.4v . but usually bash till the LVC kicks in. might try 3.5V to be safe....

Yeah I wish I'd bought the iCharger it has that option.

Read somewhere that Lipos should not be stored at full charge. could it be a cause?

BTW do you charge Lipos after the run to full charge? or to safe charge? My new quad charger does not have a safe charge option; as such I think its of no importance cause I am storing them fully charged to bash after a week or 2.

Other uses...
 

Some of my tired lipos find a new life in other lower demand dc applications. Mobil Speakers and amp(for the newly retired lipos), O2 Cool fan for the tent, lasers, LEDs anything with batteries really. Add a LVA a lipo and sometimes even a UBEC to match the voltage.

Lipos do not like to be stored at full voltage, nor do any lithium batteries really. I read a great pdf article on lithium batteries, it does have a lot of useful information about storage.

http://www.tmenet.com/pdf/LithiumBatterySecrets.doc.pdf

After I go for a run if I'm going to driving again anytime soon I charge it up full. If I know it'll be sitting for a week or more I just go to storage voltage and top it off before I go run again. For long term storage I used to put them in the fridge, but now a days I don't care about it as much. haha.