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        Discussion When do you leave a battery charged and when do you storage charge it?

#1 Fly2High Dec 07, 2012 07:44 AM

When do you leave a battery charged and when do you storage charge it?
 
Guys,

I have heard that you should not store LiPOs and LiFe cells fully charged or discharged. They should be left at a storage charge level (about 50% charged ~3.83V/cell for LiPO I think and I do not recall for LiFE)


When can you leave a battery fully charged and when should you charge/discharge it to a sotrage charge level?

What is the charge amount for LiFE?

thanks
Frank

#2 The Tug Dec 07, 2012 08:04 AM

LiFe is more tolerant than LiPo but needs the same treatment,it will not discharge much before terminating the storage charge.3.3 v is nominal voltage for LiFe.

#3 TheWoodCrafter Dec 07, 2012 08:17 AM

Many guys do not leave their LiPo charged more than a few hours.
I top off the charge from storage voltage to morning I fly.
If I don't use them I discharge them the same day.

#4 Fly2High Dec 07, 2012 09:29 AM

Many guys are saying they are leaving them charged in their transmitter, like in the case of an 8FG. I wasn't sure the idea of having a long retention of voltage was the reasont o go LiPO in a Tx. I didn't think it was good for the batteries doing this.

Frank

#5 grimbeaver Dec 07, 2012 09:45 AM

Quote:

Originally Posted by Fly2High (Post 23465386)
Many guys are saying they are leaving them charged in their transmitter, like in the case of an 8FG. I wasn't sure the idea of having a long retention of voltage was the reasont o go LiPO in a Tx. I didn't think it was good for the batteries doing this.

Frank

Low C rating batteries used in a Tx are more tolerant I think of being stored charged. You will also notice that in the case of the DX8 it undercharges to 8.2v (only 4.1v per cell).

For me I charge before I go fly, if I don't use I discharge the same day as it is rare I would use them the next day.

#6 TheWoodCrafter Dec 07, 2012 10:20 AM

What leaving your batteries charged does is raise the IR.
This will limit the discharge rate of your pack.
It will hold charge OK but it will not release it very fast.
ATX doesn't need it fast.
With the low load that a TX puts on a battery, leaving it charged will not effect it much.

#7 hoppy Dec 07, 2012 12:17 PM

The time batteries are left at full charge is culmative, therefore, leave at full charge as little as practical. Storing batteries at full charge causes the battery to not only lose it's C-rate, but also it's capacity. A battery left at full charge for 1 year at 25C loses 20% of its capacity vs a 4% loss if stored at 25C and 40% charged.

#8 Cody f86saber Dec 07, 2012 03:57 PM

Quote:

Originally Posted by TheWoodCrafter (Post 23464881)
Many guys do not leave their LiPo charged more than a few hours.
I top off the charge from storage voltage to morning I fly.
If I don't use them I discharge them the same day.

Same here.

#9 allena99 Dec 07, 2012 04:12 PM

My policy since the beginning days of LiPo's has been to charge them fully in early Spring, and put them at 50% storage level in late fall. When I return from flying, I fully charge any batteries that I used that day to full charge so that it is ready to go the next time I am going flying. So, my batteries remain fully charged for probably 9-months out of the year. I am not going to argue that this is the right procedure but you asked how I do it. Most of the other guys in our club seem to follow a similar procedure. At the price of the batteries that I buy, replacing one every two or three seasons is not a big deal.

#10 scottieusa Dec 07, 2012 06:50 PM

Quote:

Originally Posted by allena99 (Post 23468447)
My policy since the beginning days of LiPo's has been to charge them fully in early Spring, and put them at 50% storage level in late fall. When I return from flying, I fully charge any batteries that I used that day to full charge so that it is ready to go the next time I am going flying. So, my batteries remain fully charged for probably 9-months out of the year. I am not going to argue that this is the right procedure but you asked how I do it. Most of the other guys in our club seem to follow a similar procedure. At the price of the batteries that I buy, replacing one every two or three seasons is not a big deal.

Same here. I never know when I'll have a chance to fly so I like to be ready at a moments notice. Most of my batteries are fully charged all the time. I'm more worried about a missed opportunity to fly than loosing a bit of battery life or performance. Life is short.

#11 mrforsyth Dec 07, 2012 07:02 PM

Food for thought...
 
Unless one is flying small planes with small batteries, a quality charger that can charge from storage voltage to full in 10-15 minutes (a moment's notice) is a LOT cheaper than replacing abused batteries every year or two.

Additionally, batteries that have not been abused by leaving fully charged generally provide greater enjoyment as they will make greater power than neglected batteries... ;)

#12 flypaper 2 Dec 07, 2012 09:48 PM

The 6 cell 5000ma batts in my Twist 3D 40 are 5 yrs old and still going strong, and always fully charged. This thing of storage charging is way over rated. The other 2 dozen are also left fully charged, from single cell to 10 s packs, with no problems.

Gord.

#13 AeroKen Dec 08, 2012 07:33 AM

Gord - I bet if you got a new 6s 5000 for that twist you'd be surprised how much more power you got out of it.
I have a set of lipos I got at the beginning of the summer which I left fully charged almost all the time. I can still fly with them, but they are tired. Flights are much more fun with the new batch I got a month ago and have been treating right (charge shortly before flight, storage charge after).

#14 hoppy Dec 08, 2012 10:53 AM

Quote:

Originally Posted by flypaper 2 (Post 23470984)
The 6 cell 5000ma batts in my Twist 3D 40 are 5 yrs old and still going strong, and always fully charged. This thing of storage charging is way over rated. The other 2 dozen are also left fully charged, from single cell to 10 s packs, with no problems.

Gord.

Have you measured the actual capacity of the 5 yr old 6s5000 pack recently? It would be enlightening to see what has happened in 5 years.
It would also be interesting to see what the IR of those packs is?

#15 flypaper 2 Dec 08, 2012 11:55 AM

Havn't measured the capacity but it still gets the 6 mins. of hard running on the timer with lots of poop left when it goes off. Don't have a means to measure the IR..Maybe they are ready to collapse

Gord.


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