Concrete has a thermal conductivity k-value around 2,25. Timber (for example) is around 0,12 k-value. IOW a superior insulator.
So if you sit an active lead-acid battery on cooler-than-ambient-temperature concrete for an extended period, heat
may be drawn away from the bottom of it, this reduces the rate of reaction and theoretically its “fight” against self-discharge when compared to timber flooring in otherwise the same prevailing conditions.
If you have a heated bathroom floor, this is probably a good place to stand your spare batteries.
