a lithium battery prefers cold temperature and when left alone will loose its max charge slowly.
The rate of loss is the same % no matter how much charge it has.
This means if it looses %50 in a year and the battery is fully charged then you loose half your battery.
If you store the battery and it is half charged then you will only loose 25% of the full battery
It is recommended to store with less than a half charge. About 40% charged and in a cold place. Take it out and ride half a mile every 2-3 months.
In heat it also looses charge capacity at a much faster rate