I think I've got a puffed Lipo - what to do

[JohnnyOo]

Hi guys. I posted this on the battery thread, but wanted to see if anyone reading on this thread could help me out. I'm just trying to get an answer as fast as possible, cause I'm nervous with this lipo and its 12:30 at night. Please don't flame me on the double post

So... I hope someone can answer this newbie's question. I've already done a search on this, but wanted some more info.

A little background. I charged my Power Up 11.v 1300 20C battery and wanted to do a test on how long I could fly with it. I had been flying it for about 10-15 mins before bringing it back in. So, I took my Slow Stick and wanted to run it till it shut off, mark the time, and use this during my flights.

I have 2410-09Y outrunner and 20 Amp ESC I thought these specs might help give an informed answer. I have not made any changes to the ESC
http://cgi.ebay.com/2410-09Y-Outrunn...742.m153.l1262

So, I ran it at half throttle for about 5 mins, then gradually started giving it more throttle. Before I got about 2 clicks to full throttle, it just cut off. I went back to zero and it started giving it throttle again and it cut off at the same spot. So I just let it ran about 3/4 throttle for a few more mins. Then it cut off. I started it back again and gave it about half throttle. After a while I got bored with the test (at about the 15 min mark) and stopped.

Here's the problem. I charged it today after the battery had been sitting around for a few days. I checked it every 30 mins. The battery didn't get hot and everything seemed normal. At about the 3rd hour I came to check it and it wasn't hot, but I noticed that it didn't feel right in my hand. I looked closely and one of the outter cells seems like it is bulging a bit (very slight). However, it was not hot at all. Not wanting to take any chances I took it off the charger and put it outside in my covered firepit enclosed in a ziplock bag.

Here's my question
1. I don't want to take any chances and would like to dispose of this lipo. I've heard I should get a 12V car light bulb and let it drain completely. Is there anything during this process that is unsafe. I don't even want to touch this thing right now for fear it'll blow up in my hand. After I discharge it, how should I dispose of it? Just the trash can? I'm not sure if these batteries are environmentally sound and I don't want to pollute. I'm not sure if they can be recycled so if someone knows what I should do with the dead battery then please give me the info. Can I just throw it out the way it is right now or would that be irresponsible?

2. How can I make sure I don't do this again? I'm guessing that I drained the lipo too much. Is that the case? Should I have stopped my test when it cut off the first time when I tried to do full throttle, even though it was after a few mins? Or was it the repeated start ups after it cut off at about the 8 min mark at 3/4 throttle? I was under the impression that the ESC would cut off and not allow me to start up the propeller again and prevent me from doing any damage to my lipo from over draining.

Thanks in advance for reading and answering. It's 12:30 at night and I'm gonna have a hard time sleeping with this lipo (even though its outside in a firepit).

[offtom]

Could always try calling a local radio shack. Some will take batteries in to recycle them.

But then found this little site.

http://earth911.org/recycling/battery-recycling

Might tell you where you can take your battery locally.

[pd1]

Don't know where to start with this one.

The power cutting out was an indication something wasn't working the way it should.
Could have been a simple overloaded ESC( too big a prop).
Or a battery run down a little too much.

Charging a lipo, All of my chargers charge at 1C.
That means the most it will take to charge a battery is 1 hour.

From your narration, it sounds like you had the battery on a nicad trickle charger for 3 hours..
That's not good.
Lipos need a lipo charger.

If I'm not wrong on this, don't use that charger for lipos.

Puffing. Not good, but, I've had a couple of batteries swell up after charging and in a day or two they have shrunk back to where they were.
If it's just slightly swelled, it might shrink back.

Use a balance charger at a low rate to recharge the battery pack after a few days.

If it's truly puffed, it's junk. At least that one cell is.
I've removed bad cells and made two cell packs from three cell packs.

If you don't want to take chances hook up a taillight from a car and discharge the pack slowly.
Do this outside or in a fireproof container, just in case.
I have not seen lipos explode, I have seen them vent and shoot a flame like a flare though.
If you are careful you shouldn't have any surprises.

After it's fully discharged then the pack is safe to dispose of.

Good luck,
Paul

[Glacier Girl]

Something else. At least from your post it sounds like you were not flying but just doing static runs to run down the pack. If so, DON'T DO THAT!!!!!. You could very easily have damaged the motor, esc, and the pack. Static runs should only be long enough to take a reading on a meter. You are getting no airflow over the components to keep em cool, and no, the prop spinning isn't cooling your equipment.

The pack puffing may be just the start of your problems. Overheat the motor enough and the magnets will loose their power, and you'll have a motor with no power. And you may have damaged the esc too if it got too hot.

[JohnnyOo]

Thanks for the responses.

Paul - I was using the balanced lipo charger that came with my E-Sky helicopter. I've been using it without any issues and Jeff at HeadsUp RC said it was okay to use. Here is the charger I'm using

http://www.xheli.com/3emosmpllp25.html

Specification:
(1).Input Voltage：DC11.5~13.5V
(2).Input Current：1500 mAh
(3).Single battery full voltage：4.2V±0.05V
(4).Minimum chargeable battery voltage: 1.25V (the charger will indicate that there no battery if single cell voltage lower than this parameter)
(5).The restoration time of defective battery: 3 MIN (If restoration still can not be finished when overtime, indicate that the battery has been damaged)
(6).Practicable charge current: 750 mAh
(7).Compatible chargeable battery: 11.1V 1000mAh；7.4V 800mAh Li-Polymer battery
(8).Final Voltage: 8.4 ±0.1V 2 cells ; 12.6V ±0.1V 3cells
The output is 0.8A

This is the ESC that I was using.
http://cgi.ebay.com/POWER-UP-20A-ESC...742.m153.l1262

and I was using the GWS 1170 propeller, which was recommended.

When I say there's a puff, it is VERY slight. Perhaps half a centimeter at the middle of the cell.

[Dorsal]

Just fly it. A truly "puffed cell" will look like a marshmallow and there will be absolutely no doubt in your mind that something ain't right. Half a millimeter? Unless you took very accurate and detailed measurements before you started using the battery, you couldn't possibly be sure such a minuscule bulge wasn't there all along, and isn't simply a portion of the shrink wrap that isn't fully shrunk.
Just fly it.

[jstern429]

First off take the charger in your hand and go out side and toss that sucker as far as you can chuck it. I had electrical engineer friend of mine look at that charger because I was going to have him design me a charger. He told me that it charged in a way that could be dangerous if the battery was not in the best shape. It charges only to the point that one cell reaches the final charge voltage and then shuts off (not a true balance charger). Now this is OK if the pack is new but as it is used the cells will charge at different rates and will eventually the pack will not get fully charged and this is probably why the one cell has puffed slightly. I looked at tons of charger and finally found the DN Power G2 Balance charger (got it from Boom Town Hobbies for $68(www.boomtownhobbies.com)) and it charges only through the balance connector and treats each cell as it's own battery (kinda like having 4 chargers in one). This charger will charge anything from 1-4 cell packs and will charge two two cell packs at the same time. Check it out I would recommend you get one as it will be better for your batteries. Also if you plan on tossing the battery there are other things to do to it before tossing it. Do a search on Li-PO disposal and you should be able to find the proper process on that. By the way the design that my friend came up with was the same as the DN G2 charger so it's a good design.

[JohnnyOo]

Originally Posted by Dorsal

Just fly it. A truly "puffed cell" will look like a marshmallow and there will be absolutely no doubt in your mind that something ain't right. Half a millimeter? Unless you took very accurate and detailed measurements before you started using the battery, you couldn't possibly be sure such a minuscule bulge wasn't there all along, and isn't simply a portion of the shrink wrap that isn't fully shrunk.
Just fly it.

Thanks for the reply Dorsal. it was about half a centimeter, not millimeter. I'd say about 2-3 stacked quarters. I have it outdoors right now and I'll see if the puffing goes away.

From all the responses I've been getting, it looks like I should just invest in a better charger and something that reads the volts on each of the cells.

[shotgunsmitty]

Definitely a better charger.
I have a cellpro 4s and I'm very happy with it. It was more expensive, but this charger charges safely, and that's what I want more than anything overall, safety. I use cheap batteries, and I have one that's crumpled from a crash but it's not puffed. I keep an eye on it, but the cellpro charger that I have will balk at anything that goes wrong during charging, and will adjust how much power going into the battery cells all on its own.

Get a smarter charger and I'd be willing to be that the battery might be okay. But in case it's not, charge it in a fireproof environment like you normally would anyway.

[Mr.Clean]

I agree that you need a new charger. Find one you are comfortable with. I dont think that any one system is any better than any other once you deceide to spend more than $60.00 on the charger. Some have mor options and features than others. Just find the one you feel safest with.
After you make that commitment go to your local Army Navy surplus store and spend $10.00 on a 50cal ammo can. Drill a half inch hole in the side so your wires can run through and put your batteries in that can when you charge them. You can then use the can for tranporting the charger on the feild if you do so.
We all spend hunderds of dollars on homeowners policies. Don't skimp when it comes to saftey. You seem to have the right idea with this battery.

IMO, and I am not an expert on lipos by any means, it sounds to me like one of your cells overcharged. I had one do that (a minor puff). I discontinued use. It is currently sitting on a shelf. I use it for centering servos and the such after a repair or during a build. I have not charged it since the puff. I will dispose of it eventually.

Good luck.
Clean

[idealhobbies]

http://www.hobbycity.com/hobbycity/s...idProduct=2055

[JohnnyOo]

Thanks everyone for all your help. I'm gonna monitor this battery to see if the bulge increase or decreases.

Meanwhile, I think I'm just gonna order the charger that Snafu suggested since I've heard others recommend this charger as well (and Hobby City has em in stock).

Snafu: I've had others recommend this charger before. It looks pretty pretty good for the price. Do you have this yourself? What did you use for the power supply (to go from AC to DC)? Just something off the rack at Radio Shack? It says I need 9-15 volts but doesn't specify how many amps.

[gzsfrk]

Originally Posted by JohnnyOo

Snafu: I've had others recommend this charger before. It looks pretty pretty good for the price. Do you have this yourself? What did you use for the power supply (to go from AC to DC)? Just something off the rack at Radio Shack? It says I need 9-15 volts but doesn't specify how many amps.

You can make your own multi-use DC power supply using any old ATX computer power supply and a few dollars worth of parts. But the easier thing to do would be to find a power supply from an old LCD monitor. You can usually find those for free if you have any friends who work in a company's desktop support or networking shop. They're usually 12V and range from 2.5A to 5A.

I did both (made my power supply AND got my bro to bring me home a power supply from a burned out LCD monitor). I use the 3.3A LCD power supply all the time now, but it's nice to know that I've got the "Lab" computer power supply available if I want to charge any larger capacity (say, 5000mah) batteries at 1C in the future. (5 amps is as high as my beloved IMax B6 will go.)

Oh, and for the record (and the money), I can't recommend the IMax B6 highly enough. It's an awesome charger.

[JohnnyOo]

I just got my supplies in the mail yesterday. Turns out, the battery I had that was in question WAS not balanced.

gzsfrk: I went with the iMax B5 balanced charger. It was a bit more than the other charger that was recommended but I liked how it displayed the status of the battery during the charge. I also converted an old computer power supply to power the charger. It works great! Thanks so much for that link, I would've never thought to use something that I would've thrown out as the power source.

Thanks everyone for your help on this matter.

[flydiver]

The Esky is not a good balancing charger, it's cheap. I've seen reports that it doesn't balance at all.

You had 2 main problems:
1. Yes, likely you over DC'ed the lipo. LVC on cheap (and unfortunately MOST) ESC's is NOT good at 3.0v.
You should have stopped at the first LVC. Rearming is ONLY to get the plane down immediately.
Personally I don't trust most of them and fly by time. Try to not let voltage get below 3.7-3.8v resting. Try not to get capacity below 80%. By continuing to use the lipo after LVC you likely push the cells too far and out of balance. This will be made even worse by a low draw system like that.
Since the charger isn't very good it couldn't satisfactorily deal with the excess draw and out of balance situation and puffed a cell.

A very conservative person will trash the cell. Use a small auto bulb, DC until dead, soak overnight in saltwater, slice casing, soak some more > discard. Not toxic.
A less conservative person will fly it and watch it carefully. You appear to be the former.

2. Did you verify that the ESC WAS set for auto lipo? (Arming beeps?)
Twiddle the sticks wrong when powering up and it's possible you could have set it to NiXX. You need to learn how to evaluate/program an ESC, along with all the other stuff you need to learn. Programming cards help with that. Programming by sticks is a pain but possible. That ESC appears to be a Dynam.

I'd recommend a multimeter. Some people have indicated the B5 does not balance well. Others have countered that it's fine, just not as precise as some of the more picky type demand. There are some busy threads on that charger.