Once upon a time there was available at J C Whitney a relay just for that. The Volkswagen of some vintage had two six-volt batteries under the back seat wired in parallel. The relay would put them momentarily in series (while disconnecting the six-volt feed) sending twelve volts to the starter for cold-weather starting.
They may still have this relay available somewhere. They do have DC to DC converters but they are expensive. I agree with all who said it is not a good idea to run a 24 volt motor on 12 volts. I can be done safely for brief, low-power situations, but not for a continuous duty situation such as a watermaker pump. Norm S/V Bandersnatch Atlantic City NJ > I'd strongly recommend "in-lining" another battery, as Rick recommended. > Depending on how your PUR unit is powered, you might even be able to > trip a DPDT relay from its power switch; that would automatically put > the batteries in series while the unit was running, and in parallel for > charging when it was off. > _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
