Storage Charge
 

I have had my batteries in a storage charge for the winter and am about to charge them up for use. My question is, how long of a break in flying warrants putting the batteries in storage charge... What is the best way to maintain the life of the batteries?

a few days of not flying?
1 week of not flying?
1 month?

RE: Storage Charge
 

After a weekend of flying, I put my packs at the storage charge Sunday night if I know I am not going to use them til the following weekend. I finish charging them the night before I go out for the following weekend. In my case, Thursday evening, since I primarily fly Friday, Saturday and Sunday. You could fully charge them if you know you are going to fly in the next couple of days after a weekend of flying.

Since you are going to just use them for the first time after a long winters storage, I would recommend taking shorter flights and be easy on them for the first couple of cycles. I usually charge and do a discharge at least once on my TP 1010C charger before I fly them after a long winters storage first.

RE: Storage Charge
 

I can share a couple of principles with you that I have developed over time:

1. Store batteries around 40% charged all the time unless you are using them. I do this mostly by simply not charging them after my last flight of the day and they seem to be around 40-50% charged which is good enough. I then charge them up the night before I go out flying. Store them in a cool place. I aren't obsessive about this, if I happen to charge up a pack and dont use for some reason I just leave it charged and use the next time I go out.
2. Warm batteries to around 30 deg c (85 deg f) before flying them, the lower the ambient temp the more critical this is. It is amazing how much lower the delivered voltage of a pack is when cold I also believe it shortens the life of the pack.

I have a attached a picture from www.batteryuniversity.com that I think is useful showng the deterioration of capacity of a LiPo over time based on storage capacity and temperature. I think it is quite instructive.

RE: Storage Charge
 

as Joe, I always charge my packs back to storage after I have finished flying. It is a good habit and reduces charging time before flying. I use a iCharger 1010b and it has a build in storage program (per cell at 3,85VDC) which charges/discharges as needed.

Joe, you mention you discharge/charge before first flights. How do you define discharge? At my charger it wil default discharge until 3,0 V but that sounds kinda low. I can change the setting so I can follow any recommendation.

Volkert

RE: Storage Charge
 

I discharge on my TP 1010C. I set the default discharge point to 3.75V. I let it go the distance and sometimes I stop at about 2000ma discharge and then recharge. Downside with this charger is that you can only discharge at a .5A discharge rate with a 10S setup which takes a number of hours. Usually I do it twice and then fly the pack for a 5 minute flight a few times before I do a full sequence which takes 7-8 minutes. JUst keep track of the ma discharged on the charger. I think 2000ma is safe number to go to. Don't know if discharging the packs at that low of a rate matters but I do it a couple of times no the less.

RE: Storage Charge
 

Just move to some place you can fly all year round! :D

Sorry, I couldn't help myself.... [&:]

Cheers
Jason.

RE: Storage Charge
 

[8D] Love that one Jason! No problems with your packs freezing as well I guess! Brrrr....just spend yesterday afternoon flying in a force 6 wind at 9 degrees C and a bit of drizzle [&:]; still cold now....Hope that spring will now finally kickoff here.

Volkert

RE: Storage Charge
 

G'day Volkert,

Force 6 wind is about what we were flying in yesterday here in Sydney. The wind was gusting to 50kmh with an average of 33kmh. Nice temperature of 26C though and a clear blue sky. People probably think we're mad flying in this wind but often it's the type of weather we're presented with at comps. Good practice in my opinion.

It will soon get to the point where I need to warm my batteries before use.[:@]

I really can't appreciate what you guys go through in winters. On one hand it would drive me mad no being able to fly, on the other hand you could get a lot of building work done..;).

I do take a lot for granted weather wise.

Cheers
Jason.