The Panasonic battery is crucially different from all other types in that it has a sophisticated "sleep mode", When it hasn't been used for a little while it shuts down it's internal BMS (battery management system), which means that quiescent current drain stops. Unlike other cell types, lithium cells do not lose charge over time, the charge that is lost in lithium batteries when standing around is that which the BMS uses, not the cells, so shutting down the BMS automatically puts it into storage mode.
To wake the battery up from the sleep mode the initial conditioning procedure is repeated, i.e. fully charge and then quite fully discharge the battery by running it to near empty.
It's best not to have it fully charged or discharged when it goes out of use, the preferred charge level for storage being around 40%, so if you run the bike for a little over half the range you normally get, that's fine. Then remove the battery from the bike and place it somewhere cool. If it's only the odd two or three weeks at a time that the bike is out of use, you can just store it fully charged if it's not convenient to partly discharge it, but never ever store it discharged.
There's no need to charge it again every three months during longer storage, unlike all other makes of e-bike lithium batteries currently, although doing so does no harm.
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