Help! LiPo voltages at different stages ?

[Jetpainter]

I run a pair of 2S 5000mah Pulse LiPo's for the receiver on my 35% Extra, (yes I know its over kill, but they were free). I have left them fully charge for a week a few times, but most of the time they sit at 80% or so since that's all they drop to after 4 flights. they seem to be holding up well. This is my third year using them, and they were a season old when they were given to me.

My 6S 5000mah packs for my helicopter and EDF jet I charge at 10 amps and store at around 50% or 3.85 per cell. The EDF will draw them down in a hurry. They get down to 30% or so in about 3:30 minutes. If you miss the first approach it's even less. The packs I run in my T-rex 550 heli are 5 years old.

 

[John Vesper]

Is this a typo? From everything I've read, 80% is like 4.06 volts and 3.75 volts would be about 40% just wondering.

This is not in line with my experience. The numbers I quoted earlier, which come out to about 56- 58% are as high as I've ever seen in my personal experience, when discharged down to the 3.6 to 3.8 volts per cell level. There's a discharge cycle on my charger that will take a cell down to 3.2 volts. I may experiment on an old pack, when I get home, to see how much energy goes into replacing that discharge level.

 

[John Vesper]

This is not in line with my experience. The numbers I quoted earlier, which come out to about 56- 58% are as high as I've ever seen in my personal experience, when discharged down to the 3.6 to 3.8 volts per cell level. There's a discharge cycle on my charger that will take a cell down to 3.2 volts. I may experiment on an old pack, when I get home, to see how much energy goes into replacing that discharge level.

Looking at your earlier statement the 56-58% discharge would leave the battery charged to 42-48% of it's specified capacity.

 

[Snoopy1]

Sorry but I am with @Jetpainter on this 3.85 is storage and it is also at 50% of the pack capacity.
Thanks for your in put on your receiver packs. I have been running into the same thing do some flying get home and the packs are at about 80%. And was thinking just leave them there and recharge to 100% next time out. Instead of coming home discharging everything down to 3.85 V. Just a lot of work and is it worth it. From what you are experiencing it does not seem to have an impact on the cells. Thanks.

 

[Snoopy1]

I know it does not have much to do with voltage or maybe it does but what causes a LiPo pack to puff up. None of mine have ever puffed up but have some died off slowly. Or just one cell goes dead for no reason.

 

[John Vesper]

I know it does not have much to do with voltage or maybe it does but what causes a LiPo pack to puff up. None of mine have ever puffed up but have some died off slowly. Or just one cell goes dead for no reason.

The best way is to leave them fully charged, in a warm environment, for and extended period of time.

 

[pawnshopmike]

The best way is to leave them fully charged, in a warm environment, for and extended period of time.

For sure. I left a brand new battery in my car once in the middle of summer. Puffed in one day and it was a hard case pack for an 1/8th scale buggy.

 

[MarkF]

Not a typo. I own dinogylipos.com and need to know this stuff. If you guys have any questions feel free to ask.

 

[Snoopy1]

Not a typo. I own dinogylipos.com and need to know this stuff. If you guys have any questions feel free to ask.

Thanks for that always good to have information that is correct do you have same chart for A123. That would be appreciated.

 

[Bald Headed Fat Guy]

Does this chart mean that if I check a battery with one of the handheld field checkers a few minutues after landing, and it reads greater than 20-25%, that my batteries are safe?

I have been using a target of 35%, but have gotten down to 29%, a time or two. And I always recharge to either full for flying within next 2-3 days, or storage if more it's going to be longer than 3-4 days. My Hyperion charger does 99% on a full charge and 50% for storage. Am I doing it right?

Thanks!