The issue you run into with such switches is that lead acid batteries should not left off of a charger for an extended period of time, certainly no longer than a month. To maximize their lifespan, they should always be left on a 'smart', computer controlled, 3 stage charger. This can be done by either leaving your Pod connected to shore power when not in use so that the onboard charger will keep the batteries charged or by putting an external charger on the batteries while they are either still in the Pod or out of it. I always take the batteries out when we aren't using the Pod and leave them on a Battery Minder #1500 charger.
Remember that lead acid batteries self-discharge 3-5% per month, and the more discharged the battery is, the more harm is being done to it every day. Every day that a lead acid battery isn't on a charger is some amount of time off its lifespan. By far the #1 killer of lead acid batteries is not being charged sufficient/properly.