Batteries storage charge

[D.O.G.]

Hello, I know that you can balance charge more then 1 battery at a time. When it comes to storage charge, can you storage charge more then 1 battery at a time or is it safer just to storage charge 1 battery at a time? Thanks in advance.

 

[Tony]

I do as many as I can at a time. Won't hurt anything unless you mix S ratings.

 

[Smoggie]

+1 on what Tony said. For example yesterday i had to cut my flying session short so when i got home I discharged 9 batteries down to storage with them all connected in parallel. No problem as long as they are all roughly the same voltage at the start and all the same cell count.

 

[Tasajara]

I do up to 16 at one time I use 3 balance boards , just make sure they are with in a few tenths of a volt apart.
Example a battery reading 3.99v per cell with a battery 3.79v per cell should be fine. The higher voltage per cell battery will
discharge to the lower one and your charger will balance the batteries out for storage.
Just don't put a fully charged battery with one that has been used. There is too big a difference in voltage.
I try to time my flights so I come in with a battery that reads 11.4 v to 11.55 this makes my charger take just a short time to hit storage voltage.
I also use a FMA PowerLab 6 which has one of the highest discharge rates up to 8 amps which cuts my time to store pretty low.
The FMA PowerLab 6 has been one of the fastest chargers I have ever used. It has a 40amp output using a 24v power supply.

 

[Smoggie]

Discharging large batteries to storage can be time consuming. Even the most expensive chargers have modest discharge power rating, for instance the PL6 mentioned in the last post has a discharge power of only 50W which means only 2A discharge on a 6S battery. My ICharger is a lot better at 200W but even that is quite slow if you have a few large batteries.
I now use a modified hairdryer as a resistive load which I can connect to the iCharger and discharge at 40A / 1000W which is much faster.

 

[holtneil]

HI Steve where is the how to video , Can this be done on any charger ? I have the turnigy mega 400 watt

 

[Smoggie]

Neil,
Sadly no, the only chargers that support the resistive load trick is the iCharger Duo series. Some chargers like the PL6 and PL8 and iChargers will do 'regenerative discharge' to another battery, which is fine 'if' you have something like a large lead acid battery to put the charge into.

here's a video i shot recently:

 

[Tony]

And the lead acid battery (Pb) needs to be able to 'hold' the charge that is going back in it. If it can't, it will stop the discharge.