Jim, that USB power outlet does use some power all the time but nothing
like what you are seeing. I suspect your newish battery is done for or
something else is draining it. In order for that little USB device to
drain the stored energy from a full car battery in that short of time a
huge amount of heat would have to be given off. Something would melt.

I have installed several of those Banggood setups in my vans without the
issue you are seeing.

Mark

Jim Felder wrote:
> 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.
>....
> 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
>