Originally Posted by
gfunkdave
Generally Li-ion batteries are happiest if you store them with 50-70% charge. Storing with full charge is stressful on the cells (I forget why) and if they discharge too much they can become nonfunctional.
This is 100% correct. Li-ion gets damaged when you have it at 100% or 0% too long. I usually don't charge them until the night before a trip and just leave them at whatever medium charge is left when I get back home.
The worst is when people keep them plugged in 24/7 just so they are "ready" to go anytime. Li-ion has a pretty low drainage rate (at least better cells do) but you are doing some damage keeping them continuously hot at 100%.