PDA

View Full Version : Lipo puffed when not used in storage?



SweetZ28
06-27-2010, 11:32 AM
I used this lipo one time and store charged it last year and now went to go use it and it's puffed like a water bottle!
the voltage reading is 3.8V so i think one cell totally gone bad and now the second one got puffed also from the first one going bad.
The thing was brand new ran one time nothing was wrong with it when i stored it?
Guy's say lipos last so long and you get hundreds of charges out of them I don't know all the lipos i have i tell ya the truth the good old NIMH packs seemed to last and be much more usful in the long run.
How could this puff up when it was new? i once had another lipo do the same from sitting in storage do they have to always be charged and draind frequantly to stay in good shape and last long because to me if feels like if you don't use them often they may go bad?

ALSO how should i dispose of it ... disharge it all the way to Zero Volts? what amprage should i use?

Thanks any help will be great.

99z286spd
06-27-2010, 11:44 AM
You can put it in a bucket of "salt" water to neutralize the pack. it will take 24-48 hours. and then check voltage and should be zero. then you can throw it out. as far as the pack puffing......im not sure. ive stored mine before for 8 months or so but they were perfect.
maybe where you stored them it got to hot???..... hope this helps ya.

BTW I like your user id:thumbup:
:beerchug:

forescott
06-27-2010, 12:00 PM
How often should you check your packs after you "store" them? They will slowly discharge over time. But how fast??

Fluid
06-27-2010, 12:27 PM
I've stored my ThunderPower 5S2P packs for up to seven months between uses and they as as strong today as when new - at least they propel the boat as fast. I store at 3.85 volts per cell in a 72F environment, and after seven months the voltage was 3.8 volts per cell. These packs are three+ years old, I have others which are older and they store just fine too. I don't buy cheap Chinese packs so I don't know what happens with these over time.

LiPo packs should be stored between 3.8 and 3.9 volts per cell in a mild environment. They can puff from being over-discharged, over-charged, or over-heated in the past. The "newness" of cells is not much of a factor depending on how they were cared for.



.

forescott
06-27-2010, 12:34 PM
Unfortunately my budget doesnt allow me to spend hundreds of dollars for expensive lipos. So I'll have to make due with my cheap chinese lipos. Which have worked well for me so far. I guess I'll check em every couple of months or so to be safe.

SweetZ28
06-27-2010, 12:52 PM
Thanks guy's i used my ICE charger and discharged the pack to .1v cell and then hooked my light bulb discharger on it for like 10min and the battery had no Volts left in it at all.

Maybe i should store them in a different area as they are stored in a sun porch in the winter i would say 50's and summer can get 90? who knows maybe a lot of temp fluctuation can do this?

THANKS

Fluid
06-27-2010, 03:04 PM
Several battery suppliers recommend storing between 40F and 70F.

SweetZ28
06-27-2010, 03:39 PM
Several battery suppliers recommend storing between 40F and 70F.

Guess i will have to store in another place!
THANKS.

crabstick
06-27-2010, 04:48 PM
Recently learn't this lesson the hard way.

stored some lipos charged (DURRRR), in a box, in my warm server room for about a year... balance was out of whack before charging and when I used it, once cell puffed so hard it ruptured the satchel.
Another brand new pack that I had stored charged (DURRRRR) was puffed

I charged these cells intending to use them but for whatever reason put them away at full charge (DURRRRR)

Trying to think of a decent reasonably cold place to keep them..

From what I have been reading there are a couple important things to storing lipos
1. Storage charge them
2. discharge and charge at 6 months
3. Keep them in a cool area, not a server room thats about 28degrees celcius

SweetZ28
06-27-2010, 05:21 PM
I have all my lipos charged in storage mode so i guess it's the heat and cold tems fluctuating to much that may have caused the lipo to go bad... then again i am starting to think storiung them at 3.8v per cell may be to high and causing the damage to the cells..... why could't you store at 3.5 or 3.6v per cell theu won't drop belloow 3V per cell and less energy being stored would be a good think i think.....reason why they say don't leave lipos go for a long time when fully charged?

Visual Perfection
06-27-2010, 07:11 PM
That is puffed? I have two packs I have been using that look almost like that...(2 rhino packs) bought them from a member on here and they showed up that way, didnt think anything of it being they look like they should be like that.

How do I know what they SHOULD look / feel like? They work just fine.

sailr
06-27-2010, 07:34 PM
That's not much of a puff. I have seen just the heat shrink puff up that much after a hot run. I have CAREFULLY poked a couple of hole in JUST THE HEAT SHRINK, not the cell and they come right down. The shrink is so tight on some packs that once it swells up it can't go back down.

SweetZ28
06-27-2010, 08:53 PM
That is puffed? I have two packs I have been using that look almost like that...(2 rhino packs) bought them from a member on here and they showed up that way, didnt think anything of it being they look like they should be like that.

How do I know what they SHOULD look / feel like? They work just fine.

If you push on the pack with your finger and it is soft or feels like it's filled with air like a bike tube it is shot... they should be hard.... you should never use a blown up swollen lipo it's just ready for disaster!

Fluid
06-27-2010, 09:48 PM
.... why could't you store at 3.5 or 3.6v per cell theu won't drop belloow 3V per cell and less energy being stored would be a good think i think.....

I don't have the answer, but all LiPo distributors say store at 1/2 charge - which is around 3.8 volts per cell. I've had great luck following their instructions (RTFM) so I will let others try to second-guess the battery experts.



.

Visual Perfection
06-27-2010, 10:50 PM
I think like sailr said, the heat shrink is so tight it can cause air to be trapped in them, and I think that is how mine are. They do feel like there is a little air in them... I hope I didnt get screwed on these

Maybe I should try putting a small pin hole to let the air out also, don't see how it would hurt?

Visual Perfection
06-27-2010, 11:07 PM
Well I sent a PM to the member I bought them from..not sure what to do now.

Havent even charged them or anything yet, just ran them a few minutes to get them to the recommended storage voltage for now and they sit until I get a charger..but they arrived that way and not knowing anything about lipos my stupid self didnt think anything of it

Oh and sorry for the thread hijack...just fits my situation as well it seems like and hoping for some help

SweetZ28
06-27-2010, 11:10 PM
Well I sent a PM to the member I bought them from..not sure what to do now.

Havent even charged them or anything yet, just ran them a few minutes to get them to the recommended storage voltage for now and they sit until I get a charger..but they arrived that way and not knowing anything about lipos my stupid self didnt think anything of it
If there not flat and round shaped and feel like air is in them they are toasted.
who sold you these?
I woulds send them back and get your $$ back also.

Visual Perfection
06-27-2010, 11:12 PM
I dont want to put any blame on anyone, as I don't know how they were before they left..he said only a few runs on them.

Is there any way they could have puffed during shipping? He sent them charged and balanced for me.

Visual Perfection
06-27-2010, 11:14 PM
where should I store them? I am scared now lol

EDIT..original owner said they have always been like that, and if they werent safe he wouldnt have sold them. He gave me the option to ship them back to him if I feel they are unsafe, but I think I might keep them as they prob. are just fine.. I am happy he gave me the option.. good seller

SweetZ28
06-27-2010, 11:28 PM
This is the last time i will tell you this ... Maybe some other member will tell you also.....if in any way they are soft or air filled and look kind of like the one i show in my photo they are no good.
Do what you want with them but if it was me i would send them back and get my $ back there shot if they show any symptoms i speak of.

SweetAccord
09-07-2010, 08:31 PM
So once a Lipo is charged, and say they are not run for the day, how long may they sit at their fully charged state?

nomobux
09-08-2010, 06:44 AM
So once a Lipo is charged, and say they are not run for the day, how long may they sit at their fully charged state?

I think if you ask 10 guys, you'll get 10 answers :spy: My thread is "Puffed Lipo " I stopped at the airport with my lipo and talked to about a dozen guys flying electric. They have been electric for years. Not one uses the storage mode. Not one, and never a problem. I'm getting real confused on all this. :confused2:

Fluid
09-08-2010, 08:18 AM
Asking ten randon peple what they do for LiPo storage is bound to get you ten different answers. Ask the same folks the best brand of LiPo, or the best motor, or what kind of woman they alike and you'll get different answers too. Don't waste your time looking for concensus, you won't find it.

If you want to know the "right" way to store LiPos follow the manufacturer's instructions. Otherwise do whatever you want to do. Most hobbiests (air, land or water) don't know much about the technical end of the hobby anyway....



.

Insaniac
09-08-2010, 11:15 AM
Every LiPo I have ever purchased new has arrived at about 30% from the manufacturer. My Thunderpower charger has a 50% "storage" charge, so I would say anywhere between 30 and 50% for storage at room temperature.
I NEVER leave them stored at 95% or below 30% and never have had any problems.
FWIW...

FighterCat57
09-08-2010, 12:49 PM
I don't have the answer, but all LiPo distributors say store at 1/2 charge - which is around 3.8 volts per cell. I've had great luck following their instructions (RTFM) so I will let others try to second-guess the battery experts.



.

3.8v/cell is exactly where the "storage mode" on my charger leaves them and exactly (within .05v) where they come new.


Asking ten randon peple what they do for LiPo storage is bound to get you ten different answers. Ask the same folks the best brand of LiPo, or the best motor, or what kind of woman they alike and you'll get different answers too. Don't waste your time looking for concensus, you won't find it.

If you want to know the "right" way to store LiPos follow the manufacturer's instructions. Otherwise do whatever you want to do. Most hobbiests (air, land or water) don't know much about the technical end of the hobby anyway....



.

Yeah, it's kinda like going to the DMV for automotive care advise. :huh:

Alfa Spirit
09-08-2010, 01:03 PM
Your LiPo is normal,

Here' s a puffed pack

http://img717.imageshack.us/img717/5551/accusgonfl002.jpg

SweetAccord
09-08-2010, 05:14 PM
So what is the answer then? I'm not asking on storing as that is clear what to do everywhere there is Lipo information. What I'm interested in and what I don't find info on is if you fully charge a Lipo but do not run it for whatever reason, how long may it sit before you should put it on the charger and put it in the storage mode? I find some say a week or two is fine. But what is the true time or does that depend on mAh ratings?

Peace.

FighterCat57
09-08-2010, 06:46 PM
So what is the answer then? I'm not asking on storing as that is clear what to do everywhere there is Lipo information. What I'm interested in and what I don't find info on is if you fully charge a Lipo but do not run it for whatever reason, how long may it sit before you should put it on the charger and put it in the storage mode? I find some say a week or two is fine. But what is the true time or does that depend on mAh ratings?

Peace.

Since it is a chemical reaction which causes degradation over time, I would say cumulatively... minimize overall time spent at high/low voltage. I wouldn't think there to be any "safe" amount of time as the cumulative time spent under or over is what leads to total loss of use.

HTH

Jason MaxAmps.com
09-15-2010, 11:23 AM
Guys what happens if stored full the IR or internal resistance increases. This increase in IR then makes it very hard for the pack to support a high current load. This equals puffed pack either the first time you used it after it has sat for a long period or if it has sat long enough without use. And yes they will over time drop voltage as well but it takes longer than say a NimH pack. To help fight this issue store packs at 60% of their rated capacity if they are going to sit for a week or more. Lets face it we don't always know when the next run will be. DO NOT store by voltage, that is incorrect. DO take the pack if it has been sitting in store mode and cycle it once every 30 days. Top the pack off, discharge, then put back to store mode again. You are basically conditioning the pack and stopping the IR build up. In general from testing done packs that are stored improperly will have a much shorter life span say anywhere from 6 months to a year rather than 2 to 3 yrs of ones that are stored properly. IR increase issues tends to be more of a problem with higher C rated cells. back in the days of 10 to 20C stuff it wasn't as big of an issue.

Jason

sailr
09-15-2010, 04:59 PM
Not sure I follow. You say store at 60% but not by voltage? If you discharge it, doesn't the voltage drop? Are you say to discharge, for exampel, a 4000mAh pack to 2000mAh?

Jason MaxAmps.com
09-16-2010, 10:25 AM
The reason they are stored based on capacity is because a pack can reach just about full voltage way before the pack is full. Your 4000 pack at 2000 mAh is 50% not 60%. 60% of a 4000 mAh pack would be 2400 mAh roughly. Most newer chargers such as the Hyperion line we sell offer store mode which will either charge to 60% or will discharge to 60% based on the packs current charge status.

Jason

SweetAccord
09-23-2010, 09:40 PM
[QUOTE=To help fight this issue store packs at 60% of their rated capacity if they are going to sit for a week or more. [/QUOTE]

Thank you Jason you replied exactly what I wanted to know!

norbique
02-22-2011, 05:57 PM
I'm not 100% sure, but I think he said like, to take your example, discharge a 4000 pack with the charger then charge it up to 60% by capacity, that is 2400mAh. If the charger has a mAh charge limit, set it to the needed value.

Make-a-Wake
02-22-2011, 10:20 PM
Here's what i have discovered from dissecting a bad lipo.................

Inside the shrink is a thick wrap lengthwise around the lipo cells. Inside the thick wrap is what i can only describe as a "tin foil" sealed bag that the cells are in. In the cases of two of my puffed lipos, the air was actually inside the sealed bag.............not under the shrink. Inside the "bag" is the Lithium material that looks like pecan pie filling, and smells awful.

This pic one was not one of my puffed ones...................something happened to it, forget what, but it died, so i dissected this one.