Puffed my first battery. How short is too short for lipo life

[guitchess]

The other day, while flying my Bloody wonder, I noticed the battery was getting weak. I brought it in thinking that the flight was short due to the cooler morning temps. However, upon inspection, the battery was swollen and quite warm. I laid the battery in the dew covered grass out of fear of it bursting into flames in my jacket pocket and continued flying with the other batteries that I was carrying. When I got back to the truck, the voltage still showed 11v (3s) and the puff had faded.

I have pretty much written the battery off, but out of curiosity it seemed to charge fine. Although today, it faded quickly and puffed just as before.

Info:
Placed service = 8.24.15
In use about 5 times a week
Parallel charged with others of the same type
I use a timer on my phone to keep from over discharging. My target is usually about 10v.

Questions:

How typical is it to lose a battery this soon?
Is there anything in my description that may have lead to the loss?
Is this battery an imminent fire hazard?
What is the proper method for disposal?
I don't suppose there is a method for rejuvenation?

 

[razor02097]

How typical is it to lose a battery this soon?

Factory defects happen... this may or may not be the case here but generally the cheaper the battery the more likely it is to diminish in performance faster. 10V IMO is too low. By the time you get there the charge curve is already plummeting. I typically land before the battery reaches 10.5V

Is there anything in my description that may have lead to the loss?

Possibly... If the battery was discharged too low it may have lead to damage. One other thing that stands out is you said it was warm. While that is pretty normal especially after a flight, if the battery is too hot you may be pulling too much amperage from it.

Is this battery an imminent fire hazard?

Not likely. But make sure you still adhere to LiPo safety.

What is the proper method for disposal?

There are many methods. The one I use is getting a 1k resistor and wiring it to the battery's main lead and placing it in my kettle grill for a week. Afterward I verify the voltage is zero then puncture the cells with a nail. Then the battery is ready for recycle or garbage.

I don't suppose there is a method for rejuvenation?

If the battery is damaged, no.



From the way it sounds I don't think your battery really puffed. You may have a weak cell in the pack getting too hot and expanding. I have dealt with puffy batteries before...Because of my lust of overpowering stuff I have destroyed my fair share...When they puff, they don't unpuff... There was one pack that swelled up so bad you could literally roll it on a table! Set a timer, use a voltage alarm, enjoy that pack, have some fun, crash some planes. If the pack gets worse go ahead and replace it.

 

[pgerts]

You write "Parallel charged with others of the same type".

There are always hazards when charging in parallel.
You should charge one by one with BALANCE charging most of the times.
Use parallel only if the voltage of all batteries are very close and you are in a hurry.

 

[guitchess]

First off, thank everyone for their input.

I have discovered my mistake, which I'm sure has now significantly shortened the life of a couple of my batteries.

It appears as though I have been holding too close to the max C for too long. My batteries are rated for 25c(1000mah Zippy). I thought that at 3/4 throttle I was pulling about 16amps, but, upon recheck, I am drawing around 20.

Apparently, those high speed flybys had a price.

Note to fellow noobs: I was focused on not overworking my esc and motor and forgot to consider the battery. There are three components to the power system, neglect one, and it will cost you.

The battery does still work, but the capacity seems to have been halved.