@Steamer861 RE: LIPOs
I fly RC and a few of them are electric powered with Lipo batts so I had to do some pretty serious studying up on the Lipo batts to ensure longivity.
Yes, Lipos do have an optimum storage voltage, it's 3.85v per cell and that equates to approx 55% charge remaining. Many Lipo chargers even have a "Storage" mode that will either charge or discharge a Lipo to 3.85v for extended storage. If a Lipo is left fully charged, especially in a hot environment, the electrolite can migrate (settle) within a cell and cause it to overheat in other areas. This can cause what's referred to as "puffing". Puffing can also occur if a Lipo is overcharged (greater than 4.2v/cell) or if it's overdischarged (less than 3.1v/cell while under load)
So in a nut shell:
1. Never charge above 4.2v per cell
2. Never discharge below 3.1v per cell while under load
3. Store at 3.80-3.85v per cell.
4. If a Lipo shows any signs of puffing discard it. It's a fire hazard.