valhalla360 wrote:
If it's a decent quality multistage charger, just plug it in and ignore it. When the battery is full, it will stop charging.
Very, very few, if any work that way. The overwhelming majority of good chargers don’t stop charging when the battery is fully charged, but reduce the voltage to float level when current flowing indicates a full charger. This is not a problem on a battery with no loads. But if you have things like detectors hooked to the battery as RVs are wired or you forget to turn off a storage compartment light, the chargers see the load as an indication the battery is not at full charge and increase the charging voltage. This results in the battery spending 24/7 at nearly a full charge with a charging voltage above the gassing voltage. Not good for a battery.
With cold temperatures, self-discharge is minimal, so if you are going to disconnect a cable to remove the load there is little reason to bother with a charger.
I have a boat, RV, mower and several pieces of farm equipment that sit most of the winter. I use a 2A battery tender charger that I swap to another vehicle every Sunday evening after supper. Easy habit, and I generally look at the battery Monday morning to see that the charger thinks it is full. That way nothing gets cooked by a failed or fooled charger and I don’t have to keep checking all the batteries regularly through the winter.