[Milsurplus] 12v -- 24v Vehicle Power

[Michael Tauson]

On Tue, Oct 6, 2009 at 6:33 AM, Robert Nickels <ranickel at comcast.net> wrote:
> Hmmm....a lot of RVs, boats, etc that have auxiliary batteries to run
> appliances, lighting, etc to avoid discharging the battery used for the
> engine use a relay or diode "isolator" to put the aux battery in
> parallel with the vehicle battery for charging.     I have one that uses
> a simple relay, no resistance in series, and just replaced the deep
> cycle aux battery after getting 10 years of use from it.

STARDANCER, a 42' all steel houseboat that was home for five wonderful
years, had two engines plus a generator, each with an independent
start battery. In addition, there originally was a house battery which
was a bank of batteries all wired in parallel and charged either by
its own mains-powered charger or by the generator's own charging
system in parallel with its start battery away from the dock.

Later I changed this so the house battery was the generator's start
battery which simplified things greatly.  It also meant that when the
charge dropped, all I had to do was light up the generator and that
recharged the house battery.  That happened once/week plus every time
we had a power failure to the docks which was one of Winter's little
surprises.

When the engines were started, all three start batteries were
paralleled via some big nasty relays even though they were independent
otherwise.  They were at differents levels of charge but that didn't
seem to matter; the system worked perfectly every time.

IF I wanted to play with batteries & charging systems aboard the Jeep,
I'd add two batteries of distinction behind the front seats then run
them in series for 24 volts and in parallel with the vehicle battery
for charging.  This may still be done if the situation warrants so
that the start battery is unaffected by the 24 volt system.

On the other hand, some of these will be useable on a separate vehicle
(more likely a trailer) using a separate genset so the big military
gear can be operated independently of the civilian equipment without
having to light up the Jeep at all.

The solution I was originally looking for has already been mentioned -
a simple 12-24 volt converter (although one I want to make myself) to
handle relatively light loads of no more than 8-10 amps.

While I do want to build the converter, in part as an engineering
exercise since I have no experience at all with toroids, the various
battry systems are interesting and I do hope more ideas come.  Thank
you for them!

BEst regards,

Michael, WH7HG
-- 
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http://wh7hg.blogspot.com/
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Hiki Nô!