I try to end up with my battery's voltage at 3.85 volts per cell with little to no load if I''m not going to fly in the next day or two.
Today, I flew my 6 batteries (3 for my Evo and 3 for my X-Star) down all the way to 20% or less. I'll let them sit for a day or less than 2 days then charge them fully. I already knew it suppose to rain for the next several days here so I set my discharge time for 2 days (I've yet to get the 1 day setting to work correctly) and I'll let the auto discharge take them to proper storage level.
If you have a charged battery and want to get it to storage level, here's what I've found...
As for the Evo, Land right at 55% and watch the battery voltage in the app. Once it sits a minute or two after the propellers stop, it will end up really close to 3.85 volts per cell.
As for the X-Star, Land at 57%. That being said, if one cell is way off( 0.10 volts) from another cell, you have a battery going bad.
Yes, I'm really picky about my batteries. I have a truck that uses two 4s packs that cost about $160 each. What you don't want to do is store a Li-Poly battery fully charged or drained. If the voltage drops below 3 volts per cell, it causes irreversible damage to the cells and your charger will not charge it most likely.