Battery lock-out question

smkettner wrote:
Confirm the situation by measuring voltage direct on the battery terminals.
Give it 48 hours after you open the switch.

To add to smkettner's comment, if the voltage is more than 12.7 VDC, it is being charged while its connected to shore power.

If its 12.7 VDC or less, then its completely disconnected from the DC side.

Confirm the situation by measuring voltage direct on the battery terminals.
Give it 48 hours after you open the switch.

jalichty wrote:
So you guys are telling me that the batteries, being locked out, will not charge when the FW is plugged into shore power, is that right?

It really depends how its wired. On my current camper, mine disconnects the main DC panel from the battery and leaves the converter connected to the batteries.

On a previous camper the battery was completely disconnected from everything.

You need to investigate how yours is wired.

So you guys are telling me that the batteries, being locked out, will not charge when the FW is plugged into shore power, is that right?

I always have a small inexpensive multimeter ($7-$25 LOWES-WALMART-AMAZON ANY NUMBER OF auto parts Stores)


I can place the leads on a battery terminal without SHORE POWER connected and if it reads 12.6-7VDC then I know it is fully charged.

If I plug the trailer into SHORE POWER then the battery terminal should jump up to 13.6VDC or higher depending on what the on-board converter is doing. This tells me the battery and all of the in-line fuses and connections etc are making contact and connected to the on-board converter/charger unit.

If your battery is not connected to the trailer on-board converter/charger unit then it will not be re-charged when plugged into shore power.

Having a inexpensive multimeter around is a very handy tool to have around for us RV'ers.

Disconnected batteries will slowly self discharge over 1 to 6 months.