Storage charge

[D_Vail]

For storage charge the charger puts the battery at something like 3.86 if it has to charge the battery to get to that level, and 3.83 if I remember correctly if it has to discharge. These numbers may be backwards.

Anyways, why the difference? What would happen if I set both to 3.86 or 3.83?

[hemp]

Originally Posted by D_Vail

What would happen if I set both to 3.86 or 3.83?

Nothing would happen except your voltages would be different.

The variation is likely just to compensate for voltage settling. After you pull packs off from charging, the voltage will drop a little, and from discharging, it will climb a little. The amount of settling on large packs (especially good quality packs with low IR) is minimal. But Greg will reply and correct me on this, I'm sure.

Anyway 3.8V is not particularly significant. It just happens to be right around 50% charged which is a convenient number for storage. Don't sweat the hundredths.

[Wynn1427]

I would think that they would be opposite as you have indicated.

In either case the charger settings will determine when it decides to actually stop the charge. What charger are you running? I know there is a termination setting on my power lab 8. Don't recall the setting off the top of my head and would have to check the software.

Say you charge to storage from 3.7v per cell to 3.85 the charger starts in constant voltage mode (C.V.). Once battery gets to the 3.85 it goes into constant current mode (C.C.) and tries to hold the voltage to the setting. So when a load (charge or discharge) is put on it the battery voltage is not the true resting voltage. Naturally charging will lead to a drop in resting voltage and discharging will lead to a rise in resting voltage once charging is complete.

Wynn
Sent from my rooted HTC Inspire running JT.R8

[Smoggie]

As per first reply.. don't sweat too much about exact storage charge voltage. Anything in the 3.75-3.95v range is fine. Personally unless the batteries are going away for a long time and i have to think about the effects of self-discharge, I just store them at the voltage they come off the heli.
Assuming you don't over-discharge your batteries during flight then in most cases the only real advantage of charging 'up' to storage voltage is that it reduces final charge time.

[JonJet]

Originally Posted by Grumpy_Old_Man

As per first reply.. don't sweat too much about exact storage charge voltage. Anything in the 3.75-3.95v range is fine. Personally unless the batteries are going away for a long time and i have to think about the effects of self-discharge, I just store them at the voltage they come off the heli.
Assuming you don't over-discharge your batteries during flight then in most cases the only real advantage of charging 'up' to storage voltage is that it reduces final charge time.

+1^

[D_Vail]

I'm running the PL6.

I am not worried about the actual storage charge voltage, just thought it was weird that it was set to stop at two different voltages depending on whether it was charging, or discharging.

I figured there was probably a good reason for it, just didn't know what it was.

[Gregor99]

Originally Posted by D_Vail

Anyways, why the difference? What would happen if I set both to 3.86 or 3.83?

The is a single preset for storage. The preset is designed with logic it figure out if the pack needs to be charged or discharged. If the voltage is the same for both charge and discharge, it would be difficult for the charger to determine if it needs to go into the charge or discharge mode if the pack voltage is at the set voltage at the start of the cycle.

[D_Vail]

Ah... Thanks! Makes sense!