This is Linux related, sort of, so I hope ALUG don't mind the apparently random question. (cc'd to my old LUG in Wrexham, they're used to mad questions from me).
I have just bought a canal/river boat and want to use my Linux laptop on it. The PSU for it is labelled 19v, 4.7 amps. The boat runs on 12v. The simplest but quite pricy option is to get an inverter to create 220v AC then use the standard PSU but apart from cost it lacks elegance.
The boat has 2 completely separate circuits (at present, I'll probably re-wire it next winter). There is a 12v battery charged by the engine that is used for the engine starter and a few ancillaries such as the horn and nav lights. The there is another 12v battery charged by a solar panel on the roof used for cabin lights.
If I connect the two in series I should get 24v then I should be able to acquire (or even assemble) a DC-DC voltage regulator to bring it down to 19v.
Anyone see any problems with that?
-- Phil Thane
www.pthane.co.uk phil@pthane.co.uk 01767 449759 07582 750607 Twitter @pthane