li-po battery question about swelling up
 

Well I'm sorry to ask this question as it's probably been asked 1000+ times before. But why do batteries swell/puff up? Cheap batteries, wrong charging process from overcharging? What can be done to stop it, does it lead to dead batteries? We have been using a battery that is made by Enrichpower (EPi), from all sizes from 1300 3s, to 6000 2s, are they junk? Will discharging them with our Hyperion eoso606i-b battery charger, then a recharging though a cycle help?

Thanks Rod

Me too.. have yet to hear a straight answer. The only pattern I've seen is heat or left a full charge. The full charge I've heard is the water expands an puff verse heat ruins them so a puff is not all puffs:p. Me I got some that puffed for no reason all my batts are treated the same. I got some 1300mAH that were given to me , they were so bloated you could bounce them but they work they same as others??? So since I know mine were not miss treated I use them the same as non puffed aka charge in bag, store at 3.85V charge before fly an discharge to 3.85V after if not used.
Got some 3 years old still good an some 1 year an puffed ??? So all in all it's the battery aka manufacture an time of day :eek:
Rich

batteries puff up because of heat. Causes of heat is the battery being stressed in some way increasing the internal resistance, also including physical damage.
stressing comes from, Volts too high, Volts too low, Wrong spec battery for motor/esc set up. ie too low amp delivery. Ambient temps effect internal resistance effecting the amp delivery.
Swelling isn't puffing.

I have 4 planes that use lipo's all are Parkzone or another brand. Whether I use them a lot or little they all are puffed up. I had one puff up after only one flight. Maybe I shouldn't use them, maybe they are OK, I really don't know. They charge fine, the flight time is as expected, so I continue to use them. I do charge them in a charging bag just in case. I figure if they fail in the plane or catch fire, it won't be the first plane I have lost and probably not the last.

Hi Rod, you never want to discharge a lipo completely - you will destroy it. They are not like Nicads that benefit from a deep discharge occasionally.

I was fortunate that my first lipo charger indicates battery percentage during charge -

It allowed me to tell how much capacity was left after a flight - eg 30%

So I always fly with a timer and land before the batteries drop below 25% capacity

Use Higher C rated batteries than you need. ( I use 30C minimum in park flyers and 40C up to 65C in my Helis and higher performance EDFs)

Charge them at not more than the recommended C rating (usually 1 or 2)

Following these rules I have Lipos with hundreds of cycles with no sign of puffing.

I have also had Parkzone batteries swell slightly even following these rules. Most of them have fairly low C ratings. If they puff I stop using them.

With Lipo batteries - if you hear the engine surging in flight you have depleted the battery way too much already, they won't last long if you do this regularly.

If you had a charger that can show internal resistance, this would show the condition of the battery. High reading poor performance, low reading good performance.

Good idea, can you recommend any models? I might grab one..

I use the powerlab 8. Chargers that do cell readings would be better, I think Hyperion does pack readings. icharger might do cell readings.

I'd say that to the best of my understanding, Heat as well as other causes result in battery swelling.
As someone else mentioned, I have several batteries, all 4S 3300mah that have various amounts of swelling. At the same time,
others, used and stored the same, have not swelled,
I also scrapped a fairly new 6S5000mah due to swelling of one innermost cell.

Noticeable differences also seem to be cells that don't want to easily balance, less usable capacity, etc.
There are two batteries that have light swelling, and seem to be OK.
Another couple have heavier swelling, and I don't use them for other than such things as bench testing.

Another comment is that storing at close to full charge seems to contribute to the problem with some batteries, and not others.
????

Normal discharge/Charge cycles don't seem to be a factor.
I'd guess that something to do with the cell construction/chemistry is a major player.

How do you explain swelling on a new battery that sat 4 years never charged or used?

Don

there's still chemical reaction in the batteries, at a certain voltage and temperature of the lipo, the reaction slows down. Lipos stored in a hot place will be at more risk than a lipo stored at a cold place, if both lipos are equal in cycles,volts and brand.
Some lipo's have a habit of the cell voltage raising over a period of time.

Defects that "grow" over time?
As I remember, it can be similar to what happens in a PB battery when it sulphates.
(Since most of the PB batteries are vented, they don't balloon.)
Or, perhaps impurities/irregularities in the battery.
Even PB car batteries age, and usually aren't that great after four years, unless they were stored
sealed and dry with no electrolyte (new four year old battery).

At the very least, LIPO's may still work, but at significantly lower storage capacity.

I'll still try useing LIPO's with very light ballooning, and retire or dispose of those that have significant ballooning.
I've had LIPO's that failed, ballooned, and LIPO's that failed, and didn't.
An OLD 800mah 3 cell I just scrapped did not balloon. Cells read ,55, 0.0, 1.52

LIPOs self discharge over time. when they drop below less than about 3v per cell, the cell is damaged.

I have had a lot of batteries puff over the years, but I can't get my FlightPower LiPo's to puff.

So It seems some brands are more susceptible than others.

http://www3.towerhobbies.com/cgi-bin...EARCH=EONXLITE

That's good because they are very expensive.

So ??? we are back where we started from so some puff some don't but then someone says there's never did. Some ways say it's are fault we abused them until theirs puff now it's the batteries fault. So far the internet has said if it works use them, no one has said a puffed battery failure caused a problem ??? IS THIS SO INTERNET ! I think we all need more input of using a puffed batt that puffed with normal usage.
Rich

i have been using lipo batts for quite long time and i have experienced all the methods but no outcome,except after coming back from flying field i will connect my used batts to my charger which is bc-8 and bring them to storage position and then put them in fridge top shelf, so this way batts never swell up, even those batts which earlier was swell en up, by keeping in fridge gets flatten, may next charge again swell up but after a regular continuous use ,storage charge and keeping in the fridge you will see the batteries swelling up, keep decreasing or may not swell any further.
so please try, hope she doesn't say NO!

i have been using lipo batts for quite long time and i have experienced all the methods but no outcome,except after coming back from flying field i will connect my used batts to my charger which is bc-8 and bring them to storage position and then put them in fridge top shelf, so this way batts never swell up, even those batts which earlier was swell en up, by keeping in fridge gets flatten, may next charge again swell up but after a regular continuous use ,storage charge and keeping in the fridge you will see the batteries swelling up, keep decreasing or may not swell any further.
so please try, hope she doesn't say NO!

Go to this site and read this and will know a lot more on the subject of swelling LiPo's. one of the basic problems is water contamination.
Good reading if you like chemistry.




http://barnson.org/node/1842

Another comment - - -
Some of the LiPos sold for R/C A/C use have a very tight and stiff shrink wrap.
These do not swell nearly as much as those with a stretchable shrink wrap.

?? more detail
you checked IR before puffed then it puffed an IR increased ??

many thanks,now i have got more idea about this undesired common problem, but still i do not know by keeping the LIPO batteries in cool place like in fridge, will it help us to prevent them from swelling up , of course beside to all matters that we should bear in our mind like appropriate charging current, avoid over charge , discharge current ,low voltage and etc.

?? more detail
"you checked IR before puffed then it puffed an IR increased ??".
Too much trouble!
The voltages were measured with virtually no load. (DVM)
Next, the puffed batteries were difficult to impossible to balance,
using a Bantam BC6. Finally, the usable capacity was considerably less.
(~ 50%)

hello...


A battery charger is a device used to put energy into a secondary cell or rechargeable battery by forcing an electric current through it.
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OK Thanks
Mine have not shown degrade so all I can say when I fly the puffed show no deference but ! I don't have cba etc to test at high currents.
maybe it's just water "gas" as said expanding. But! their you say yours degraded I can not disagree maybe mine has Iam just not using enough current to notice. I see no difference in balance all stayed +/- 20mV using those cheap digit readers 3.86 can only see last digit.
rich