Hello Paul,


I'm going to be in plane camping at Oshkosh this year, and I'm wondering
how I'm going to keep my camera batteries and iPod charged. I know from
harsh experience that keeping the airplane master on to use a cigarette
lighter adaptor runs down the plane battery pretty damn fast, so that's
not a good idea. Is there such a thing as a battery powered portable
generator?


We have one of those here in case the power fails, mainly to keep the
wood stove fans running for a few hours. It is a yellow "Portawattz"
unit that can be charged at home or from a cigarette lighter adaptor
(comes with it). A little larger than a six-pack and with a nice handle.
On our version they claim it could also help starting an engine in a
pinch. Well, I don't know about that, I guess it won't turn over a big
Lycoming. Anyhow, they even threw the starter cables in.

Bought it at Sam's Club but that was years ago, slightly under $100. The
18Ah battery in there is lead-acid. Of course that means the unit weighs
as much as a motorcycle battery.

It also has a 300W inverter mounted on the side if you need 120V. But
don't hang sensitive electronic gear onto that, it does not produce a
clean sine wave. It's probably not recommended but once we did run a
little TV set from it.

Nowadays these come in various sizes:
http://www.xantrex.com/web/id/8/type.asp

I guess for Camera batteries and iPod stuff you don't need one as big as
ours.

I don't know about the rules and regs for aircraft in this case but one
solution that is popular in RVs is to have a separate battery mounted
somewhere. This aux battery gets topped off gently by a charge
controller and is completely disconnected from the vehicle power rail
when parked.

Regards, Joerg

http://www.analogconsultants.com