Storing unused lipos. Whats best?

[tiddler]

Just a quick simple question on how best to store any lipos not in current use.
Fully charged or partially discharged etc.
What is recommended?

[asomaro]

Just a quick simple question on how best to store any lipos not in current use.
Fully charged or partially discharged etc.
What is recommended?

The stock answer is that you ought to store at 3.85v per cell. Most manufacturers will ship out new lipos which will have that rate of charge per cell.

I did read somewhere that lipos will last longer if they are not stored whilst fully charged.

Cheers,

[Rctintin]

Store at 50% charge, and in a constant temperature if poss. As another piece of mind, keep them in a Lipo sack.

[liambaker996]

i store my lipos fully charged and when i am going to use them just give them a boost before doing so

[EtheAv8r]

Storage charge level should be 3.85volts per cell. That is what they are when shipped. On the Innovator that is pretty close to the tail wag voltage (usually 3.75v - 3.8v by the time you land and switch off).

Do not store long term fully charged.

[moyesboy]

They say store at 50-60% charge (which is what the posters so far have all said).
However one of the reasons for doing this is becuase a fully charged lipo must not be allowed to get cold - keep above 10 deg C.
Lipos are always shipped at 50-60% charge as they get very cold during shipping.

I generally keep my lipos fully charged and in the warm. The idea being they are ready to fly immediately. They don't really need topping up - they hold maybe 95% after 6 months or more. Certainly don't seem to need topping up after a couple of weeks.

Some of my lipos have been kept fully charged and used on average once a week, and they are still going strong after over 2 years.

[liambaker996]

what is the problem when you store fully charged???

[chris jones2.4]

usually if storing them the cells should be over 70% charged

[robgt]

what is the problem when you store fully charged???

If they get too cold they can go over voltage and damage can occur in the cells.

Cheers,
Rob

[acwman]

what is the problem when you store fully charged???

If you have them fully charged, and if the lipo is then stored anywhere alot cooler to where it is charged, the cell voltage can go up and knacker the lipo.

One of the reasons why if you fully charge your lipos at a flying site where it is cold, and you don't use them, take them home and bring the lipo into the house, that can knacker them aswell..

I think the cellpro chargers can detect temperature, and charges lipos to 90% capacity if it is colder than a certain surrounding temperature.

[robgt]

I think the cellpro chargers can detect temperature

Yes, they do.
They go into a cold weather charging mode.

To get it out of cold weather charging mode (if you move the charger somewhere warmer while still being plugged in) you must cycle the power to the charger.

Cheers,
Rob

[moyesboy]

One of the reasons why if you fully charge your lipos at a flying site where it is cold, and you don't use them, take them home and bring the lipo into the house, that can knacker them aswell..

Bringing cold charged lipos into a warm house will help them avoid being damaged surely?

If you fully charge your lipos in a nice warm house and take them to the cold flying field and don't use them they might be damaged (my chargers stay in a box with a microwave pet warmer in it in winter at the field).

Think of it like the lipo shrinks in the cold and all the electric can't fit in it anymore.

If you fully charge your lipos at a cold field with a normal charger it won't do them any good, but the cellpro has a cold weather mode to avoid that.
I found my simple multifunction charger with lipo balancer doesn't charge my lipos as fully as my cellpro. Take them off the chargerand put them on the cellpro they read less than 90% and the cellpro wwill charge them for quite some extra time and put some mAh in. So it seems that charger has an allowance for the cold - or just fails to put all the charge in!

[tiddler]

Ok, Thanks gents.
So if I've got this right, its ok to store them for some time fully charged as long as they are charged indoors and kept indoors in a warm environment. Yes.

[Rctintin]

+1 on the cellpro charger. I thought it had a problem only charging my cells to 90-91%. Then I read the hand book!! Very safe charger, everyone should have one!!

[David Drew]

Mine are stored fully charged & live in the airing cupboard. They're warmer than I am in winter

I use a microwave type neck warmer in the lipo box in the winter when going to the field & only get them out last thing before a flight. That way they don't get cold & warm up anyway as they are flown.

I have no idea if this is all correct, but it keeps me from getting bored on long, cold winter days.

David

PS......Happy Christmas everyone & a very happy 2010.

(Am I the first???)