hi RC world just wanted to ask it is natural for a LIPO to start ballooning after a while they still work fine but they wont explode will they..i use nanotech 4s 14.4 volt 5000 mah battery's...thank's

How long is a while? They will puff when they are getting near their end of life. The internal resistance gets higher with age and that creates heat, which makes them puff. Or you could be running them below 3.2v per cell before you quit using them or your low voltage cut off kicked in. On the other hand, if you have run them too hard and heated them up constantly, they will puff. If the latter, use a smaller pinion and keep an eye on their temperature and adjust as necessary.

why is this posted in elect offroad?

I'm no pro, but definetely not a good thing. I know that for sure. I would probably be too worried to use it, so I'd strongly suggest replacing it and taking better care of the next one. Also, on top of what the other person who replied said, make sure you are storing them at the proper voltage if you have to store them for over a week I'd say. Temperature also plays a big role, I know some people who have dedicated fridge space for lipos. (A little weird if you ask me) good luck to you though.

thanks guys they havn't ballooned a great deal just a little not sure what there discharging on empty but they are stored in a very cool place don't worry about that......how long do 4s last for anyway with part time use not daily use...or how many times can hey be charged before they die.

because i have 4 electric offroad cars and use lipo's..where else would i post it......

This could possibly be more for the rookie section. Anyway, the batteries are con-CAVE? Really! I've never heard of that. Idk if you know, I assume you do, but just to make sure, concave is in, and convex is puffing or ballooning. But either way they are definitely being over discgarged or over charged or even not balanced properly might be a factor as well because some cells would be more discharged than others after a run. It's probably just one cell, not all.

yeh sorry i am actually a skater and was just think of the word when i was writing i realised the mistake after ward's when i shut down but it's actually the opposite...i use a hyperion EOS0615 and my setting's on the hyperion are set right to my battery from what i can gather i always's charge to %100 to my TCS which is a setting on the hyperion. i've gone on UTUBE to have a look at vid's but there's not much on there showing you detailed vid's on charging a 4s lipo my friend has one and charge's the same battery's as i do so he did the setting's for me .....my mamba monster programming card is set on CUTOFF VOLTAGE.....auto lipo.......... AUTO LIPO CUTOFF VOLTS/CELL.....5V....that's it really are the setting's wrong...as i've noted it's a 2200 kv set up NANOTECH 4s 14.4 5000mah 30-90 c burst rate battery...but i'll tell you what my car's go pretty quick and i get good run time in a battery..

Storage mode is key. leaving a lipo fully charged for weeks to months will make lips puff. Regular usage and life span will play little in puffing. I've got cells over a year with no puffing. i accidentally left one charged for a month and there it went. i usually discharge within hours of charging.
http://www.promatchracing.com/PMlipoinstr.pdf

thanks trigger sometimes i do have battery's that are stored with charge in them so there ready to go....i actually didn't know that.

I just replied to a similar question in the rookie zone. You might want to look at that. good read in the site I mentioned .

Balooning is not only a safety sign but a performance one too. Why chance it? Seen too many fires and had first hand experience with lipo fires in aircraft to take the risk.

Jon.

ok thank's guy's i just assumed ballooning was normal after a while considering how much power these thing's give out... and there not the cheapest thing's either so you want to get the most you can out of them.