First thing, you have to be very careful with car batteries in your home!
Normally, for backup, you would use sealed GelCel batteries. Some car
batteries are vented, and release Hydrogen gas while charging. Here is a
link that explains what can happen!

http://www.rayvaughan.com/battery_safety.htm

They make battery boxes with safety straps, to help contain such an event,
but I still wouldn't recommend it. You'd be better off selling the
batteries you have, and buying some GelCels.

Lark Battery sells GelCels on eBay, and is reasonable. I just purchase a
couple to rebuilt my UPS (Uninterruptible Power Supply), for my computer
room.

Bill Crocker


"DX99" wrote in message
news:Ocane.16813$tv3.6440@trnddc06...
Getting ready for the upcoming hurricane season here in FL and wanting to
develop an affordable power backup for my radio desk in the inevitable
event
of a power outtage. I have 3 brand new 12-volt automotive batteries -
unused - in my garage. How would I go about wiring to power 4 scanners and
a
shortwave? All suggestions/directions appreciated.

K