Power Supply's Storage Vs Discharge

[D.O.G.]

Hey there. Question here. After I fly my helis/quads and the batteries cool of, I always storage charge my batteries before charging or putting them away til next time I'm ready to fly. Sometime I don't get the chance to fly because life gets in the way Lol. Anyway, with my batteries having a full charge is it OK to storage charge the battery after it's fully charge or should I discharge instead. I've been storage charge the batteries but someone brought to my attention that I should discharge instead. What's you input on this?

 

[Tony]

Storage charge and discharge from a full pack is the exact same thing. You are removing voltage from the pack. As long as you get it down to 3.8vpc then you should be good.

 

[D.O.G.]

Thanks Tony. That's what I thought

 

[Tony]

Let me add this to what I stated earlier. When I hear both of those phrases I think of doing it with a charger. In order for the storage function to bring down the voltage, it would just put the charger into discharge mode and drain it as if you put it into discharge mode. It's always more fun to discharge a pack in the air, but sometimes you can't. And this is where something like URI's discharge bank comes into play.

 

[Tommy Rogers]

Tony-
Can you elaborate not the “URI discharge bank”. I have th ISDT discharger along with a homemade discharge bank for my 3s 450 packs. I want a faster discharge bank for my icharger setup that I can use as a resistive load on the charger. Thanks.

 

[murankar]

It's still a work in progress.

Basically I run 5 5ohm 100w resistors in parallel . The basic discharge bank is just that. You plug in up to a 4s pack with a cell checker on it and wait till about 7.3 volts while under load and unplug your pack. Watch the cell checker and see if your at 7.8 volts per cell. If so that's storage charge.

For 6s you will need to add some kind of extra passive cooling (ie giant heat sink) and some kind of mechanical cooling (ie BFF, big freakin fans).

Ideally You will want high cfm fans. I like blower fans or squirrel cage fans. You will need to move a ton of heat for the first 3 or 4 minutes of discharge . This particular load bank is under rated for the watts of a 6s pack without cooling. You can do it but you need to get the resistors cool, quickly. The heatsink and fans should be enough.

If not the repeat the cycle till 7.8 volts is attained while not loaded.

Most decent chargers can do this very thing but it takes forever to get to storage.

My goal was to use an arduino to control the circuit. I may get back to it this fall. Right now I am trying to incorporate it into my charge case.