Is it okay to store fully charged batteries?

Lithium-ion batteries have a very bad characteristic, which is the aging of lithium-ion batteries. That is, after a period of storage, even if the lithium-ion battery is not recycled, part of its capacity will be permanently lost. This is because the positive and negative electrode materials of the lithium-ion battery have already begun their exhaustion process since they left the factory. Different temperatures and battery charge states have different aging consequences. The following data is excerpted from reference [1] and listed in the form of percentage of capacity:

Storage temperature--40% state of charge-------100% state of charge

0 degrees ------- 98% (one year later) ------ 94% (one year later)

25 degrees -------96% (one year later) ------80% (one year later)

40 degrees -------85% (one year later) ------65% (one year later)

60 degrees -------75% (after one year) ------60% (after three months)

It can be seen that the higher the storage temperature and the more fully the battery is charged, the greater the capacity loss. Therefore, it is not recommended to store lithium-ion batteries for a long time. On the contrary, manufacturers should recycle them like rotten food. Users should pay close attention to the production date of the battery.

★If the user has idle batteries, the storage conditions recommended by experts are that the charging level is 40% and the storage temperature is below 15 degrees or lower.

However, nickel-metal hydride batteries and nickel-cadmium batteries are almost not affected by this aging effect. Nickel-based batteries that have been stored for a long time can restore their original capacity after several deep charges and discharges.