JTMinQC

Having problems with a HAM radio, someone suggested I check the input
voltage, while xmitting. Since I was in the motorhome, and it was plugged
in to shore power, (at home), after checking the DC voltage, which was as
expected (12.6 VDC), I put the meter on AC voltage and checked. Well, it
read 27V!!!! So thinking that maybe there was some leakage, or somehow the
AC was leaking onto the DC circuits, I disconnected shore power, and took
another reading: 27V on the ACV scale, and this time measured directly at
the battery!!! Not to be outdone by such a little problem, I took my
volmeter to the car, lifted the hood, and checked directly on the battery of
the car, not the motorhome, and the car was not running: 27V!!!

What am I reading? I could understand some pulsating DC being read as AC,
when the alternator of the car is going, but the engine was not running and
there was no outside poser applied to the vehicle.

As it seems to be normal, I am not overly concerned, but I am really
curious. Does anyone have any idea?

VA2JTM.