I recently added some really cool accessories to my 83 diesel Westy. On the
dash, I added one of the banged.com "motorcycle" combination USB/voltmeter
outlets (just the dual USB port) on the dash by enlarging the hole for the
factory eberspacher heater switch.

In the rear, I removed the rear seat ashtray and created a brown blanking
plate out of painted aluminum that precisely fits where the ashtray door
once fit, making a flush surface across the base which of course still
snaps into its hole as before. Into this I mounted the USB port and
voltmeter combination so that passengers and campers will have charging
access and I will be able to see what the voltage is at night and charge my
devices while I sleep.

All well and good, I love it that I can see the battery level from the
driver's side of the car just by looking into it.

Except that what I see is the battery dropping precipitously. This would be
no big deal before I got a nice TDI jetta which has replaced the camper as
my daily driver, giving it a well-deserved rest from roadwork. But now that
I only drive the camper once a week or so, either the LEDs in the voltage
indicator or the USB ports themselves are pulling it down say two volts
every 24 hours. I was gone all weekend, so today I have about 8.5. It's
nice that I don't have to get inside the car to know that, and because of
the external Anderson Powerpole connector wired to the battery I do not
have to open a door to remedy the problem, but it needs a solution.

I never had this problem before the new additions, by the way. The batter
is just a year old.

Which, the USB side with its LED indicator, or the LED numeric display, is
causing the problem? I would like to be able to switch the offender off.Or
maybe something near the fuse block, to turn everything off when it's
sitting in the driveway or not in use at a campground?

Thanks,

Jim