I thought that the Gem would wake itself up and charge itself every 14 days if left in the off setting, but there’s nothing about it in the manual.
I wonder if it is better to keep it in the on mode and leave it plugged in all winter. We store it in an unheated shed, so I don’t want the batteries to go down in the cold.
Depends on the charger. You do NOT want the batteries to freeze so keeping it on maintenance charge is the best idea. I unplug my charger, wait 1 minute or so and then plug it in again. I do this every two weeks during cold storage. I also check water levels monthly.
Mine sits in a unheated garage. I just unplug the charger about once every 2 weeks,then plug it back in after about a minute. I have “after market” Gel Cell batterys in it,and they are fine.