On Sat, 16 Sep 2006 12:12:04 GMT, ml wrote:

my presumption was the regulators would be at least 86% efficient,(manuf
spec's) while not great i figured if i simply got more batteries as
soon as i put load past a certain run time volts would sag w/o a reg

Hi Myles,

86% seems rather poor for a switcher that is dedicated to 13.6V (or
lower) in and 12V (or higher) out. I would have expected it in the
90s.

so the question sorta became do i add more battery to compensaate for
the loss of 'regulator' to get the time i need or simply just pile up
the batteries

Depends on the quality of the batteries and how close they track.

right now i figured 4--8d sized gell would do the trick w/a little
help from a regulator

whcih do you think is most efficent?

I agree with, and use what Ed suggests. I have two batteries floating
on a 20A capacity power supply. Each battery and supply are fitted
with high current connectors (the battery connectors used in electric
lift equipment). They also have additional high current connectors to
fan out to the equipment. Don't forget inline fuses.

My batteries are built from Hawker-Gates SLA CYCLON cells:
http://www.batteryweb.com/hawkersla-...bel=singlecell
which have 25 A/H capacity. This configuration allows me to swap
batteries and cells. The cell swapping, however, is only on the
occurrence of its failure, not as a routine.

The two batteries (no supply) were enough power for light duty over
field day weekends.

73's
Richard Clark, KB7QHC