As you'll determine from this query, an electrical engineer
I'm not, despite many years afloat. Anyway, here it goes.
I've burned through a couple of handheld vhfs in the last year, and 1 Iridium
satphone. It was the Iridium
, of course, that really got my attention. (I bought some seriously cheap
VHFs off Amazon and have small kids
, and so attributed those deaths to one of those primary causes.) Anyway, with both the VHFs and the Iridium, the behavior was the same: the batteries (lithium ion) stopped charging
. Both were plugged in continuously to our 12-volt DC system through a "cigarette lighter" adaptor.
A fellow cruiser here in the Galapagos
advised me to check out where I might have some stray AC voltage in my system. And, indeed, according to the multimeter, when I'm charging
(engine alternators and solar) I'm producing around 3 volts AC (as measured directly on my batteries). It was his thought that this voltage would mess with the sophisticated electronics
in those lithium ion batteries and fry them—and, potentially, damage other electronics
on the boat.
Is this possible? AC in a DC system? Is my inverter
to blame? How do I eliminate or contain that AC voltage?
I plan to run some more tests tonight and tomorrow morning: turn off the solar
, measure without engines running, etc. But, at first glance are there any electrical
geniuses out there having an "ah ha" moment that they can share with an electrical neophyte?