On Mon, 28 Sep 2009 08:52:38 -0700, Bill wrote:

How about getting rid of all those batteries in various devices in the home
and connecting the battery connections to one central battery?

That is to run separate wires when wiring a home and these would carry say
12 volts DC. There would be a central large battery and battery charger like
the type used in a computer UPS.

When I was thinking about this, I was going to put a bank of inexpensive
(relatively) car/truck batteries in a dedicated vented area out behind my
workshop and potentially move to 24VDC rather than 12 due to the losses
involved in low-voltage DC appls over any kind of distance (initially
testing just for the workshop, and if successful wiring the house, too).

Charging / supplemental power could be via all sorts of means, of course.

Then at each electronic gizmo which needs a battery, use a "battery
eliminator" along with a voltage regulator to supply it with the correct
voltage. And plug this into a nearby 12 volts DC "outlet".

The problem is that you'll either have the inefficiency of running DC-DC
convertors all over the place, or in hacking your devices to better match
them to the available power (lots of stuff does the regulation on-board
rather than in the wall-wart).

Personally I was thinking along the lines of doing it to power some of
the lighting and things like my laptop which can be easily adapted, but
it wouldn't be possible to completely switch off the AC supply at present
- but maybe one day there'll be a standard for low-voltage DC outlets and
devices will be available that'll just use them.

cheers

Jules