Storing any battery, 18650, 20700, 21700 or LiPo should never be done at full charge. I have several new 18650's, 20700's and 21700's - - - those I store at 3.6v (storage voltage). Every month or two I check those. If any fall below 3.6v I top them off to 3.6v.
As to LiPo
batteries...... the experts recommend storing those at 3.8v and periodically checking them.
You should never store a fully-charged LiPo battery. Instead, it should be brought down to “storage voltage”, which is 3.8 to 3.85 volts per cell. There are a few ways you can achieve this. If the LiPo cells are currently under 3.8-volts then you can charge them up to this level.
Learn the proper way to charge, discharge, balance, store, and dispose of LiPo batteries. Also, learn how to prevent and, if necessary, extinguish a LiPo fire.
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