At the charge level and temperature its maker specifies, switched off, and checked periodically rather than at the end of the season. A station left full and warm ages faster, and one left to drift towards its cut-off may refuse to wake.
A station kept for emergencies spends its life doing nothing, and how it does nothing decides how much of it is left when it is needed.
The two ageing mechanisms
Calendar ageing, which is faster at a high state of charge and at higher temperatures; and self-discharge with standby consumption, which pulls the pack down over months. Storage advice is an attempt to sit between the two.
Why a check interval exists
Every station draws a small standing current even when off. Left long enough, the pack reaches the management system’s cut-off and disconnects, and waking it may require a specific procedure — or may not be possible. Checking at intervals keeps the pack above that point.
What the maker specifies
A storage charge level, a temperature range, and an interval for topping up. Those three are product-specific, they differ between makers, and they are in the manual rather than on the box.
The one that is not about the battery
Somewhere dry, with the vents clear, and not in a sealed case that traps warmth. A station stored in a hot loft is being aged deliberately, whatever level it was left at.
What people ask before they order
How often does it need checking?
Makers state an interval, commonly expressed in months, together with a level to recharge to. The point is to intervene while the pack is still above its protection threshold.
Does leaving it plugged in help?
It avoids the drift but holds the pack at a high state of charge, which is the other ageing mechanism. Which the maker prefers is stated in the manual and it varies between products.
Last reviewed 16 September 2026