Average Battery Life and Safety Concerns

[BeeRAD56]

I have a battery that was part of my original H pro package purchased in early March of this year that has me a bit concerned. It runs hotter than my other 3 after a flight and the skin within the frame is puffed up after landing.

This battery has roughly 40 flights on it, starting at 16.7v and generally ending a 14.8v unloaded.

My second battery (also part of the original purchase) has roughly 35 flights on it with the same starting and ending voltages, and it's now starting to end a flight warmer than #3 & #4 (purchased later) and it's puffing up slightly.

I'm a newbie to Lipo's, but it's my understanding that a puffy LiPo is can be no bueno! With that said, my questions are:

What is the average life of a Tyhpoon H, OEM battery ?

At what point is a puffy battery truly a concern and, to what degree?

Thanks as always!

 

[PatR]

A puffy battery is of concern the moment package inflation becomes evident. From that moment forward they are unpredictable and can fail in the worst way at any time.

Average battery life is hard to say with Yuneec batteries. We have nothing to establish the cell quality to go by. I have 8 good batteries but none of them have more than 37 charge cycles on them. None of them are demonstrating indicators of impending failure as yet.

 

[BobW55]

BeeRad,
If the battery is puffed to the point that it will no longer "SMOOTHLY" fit into the H battery compartment, I would give serious thought to neutralizing it and finding a replacement.
There are so many variables that can affect battery life. Charge cycles, charge rate, discharge rate when flying, storage voltages, just to name a few.
Like Pat said, the H is still kind of new, hard to say what life expectancy from the batteries should be.
I have seen a few Lipo fires, they are not pretty, and usually will damage the aircraft beyond repair.

 

[Fruitbatmatt]

Having produced flight reference cards for the H, Yuneec Uk quoted 100 cycles as the lifespan of the battery. I'm using the official Yuneec A10 balancing charger. Although expensive, I have a good peace of mind having the facility to discharge batteries to storage level (15.2v), discharge entirely, balance, charge etc. Personally, if I witness a swollen battery, then for me that will be the end of it.

 

[R12NDS]

Im with fruitbatmatt...puffy cell = disposal!

40 cycles is nothing...a good quality, well maintained battery should do 400 charge cycles in optimum conditions.

I would be looking at contacting Yuneec and complaining...particularly if the second one is showing the same signs of failure.

Good luck!

 

[BeeRAD56]

Thanks to all for your input. I'm going to keep an eye on all four of my batteries, none of which puff up beyond the battery frame at present. I flew today at 84 deg. and one my batteries (that I wasn't worried about) got pretty warm and chubby at the end of the flight. I'm trying to think of a punch line to warm and chubby at the end of the flight and coming up short. I'm here all week and don't forget to tip your waitress.

Seriously, my base elevation is 4,900 feet which I think has something to do with the membrane expansion when hot. I'll continue to observe and report back with anything of value.

Thanks again to all.
Brad

 

[PatR]

Perhaps coming up short with the chubby is the punch line?

 

[kohle65]

Thanks to all for your input. I'm going to keep an eye on all four of my batteries, none of which puff up beyond the battery frame at present. I flew today at 84 deg. and one my batteries (that I wasn't worried about) got pretty warm and chubby at the end of the flight. I'm trying to think of a punch line to warm and chubby at the end of the flight and coming up short. I'm here all week and don't forget to tip your waitress.

Seriously, my base elevation is 4,900 feet which I think has something to do with the membrane expansion when hot. I'll continue to observe and report back with anything of value.

Thanks again to all.
Brad

When you are flying Its normal that the lipos are getting hot. They should not get hotter than 60cel.
You should invest into a professional charger
To see the state of every cell after charging and more.
My battery swollen after charging it when it was still hot after a flight. You must wait that the battery cool down. It's about the chemical reaction and the gas which is produced in the battery. A friend of mine keeps his lipos for storage in a cold place when he don't fly. Before he fly he warm them up to 24-30cels. Normally it's good when you do this in winter. I still fly my swollen battery because my charger shows that the cells are OK.
Lipos like to be charged and discharged. More cycles for a lipo is better. Lets say you fly every day, and need per day 2 lipos. It's better to charge this 2 lipos every night and use again. If you have for example 4 Lipos the time between charge and discharge will be longer and is not good for a lipo.
The best is that a lipo is charged and discharged on the same day, or a night before. After discharge and no use for a while charge to storage voltage. For this you need a professional charger. So don't buy more Lipos for more flight time when you don't use this time. Better charge and use as often as possible the same lipo.

 

[samsflite]

Out of interest how do you keep your batteries in between flights? Do you leave them empty, charge them a bit or immediately charge them up ready for the next flight whenever it is? The lack of storage function on the stock charger is possibly the reason.
As mentioned above, even a poor but well maintained and non-abused LiPo should last a couple of hundred cycles before it puffs and internal resistance starts to increase significantly. The good ones should last 4-500 cycles. This all goes out the window with a LiPo if they spend there life fully charged or discharged.

 

[Chukky]

I store my batteries fully charged and at 10 degrees Celsius in a small fridge the batteries are original and at least 12 months old and are as good as new