News f2s wrote:
I've used petrol gennys for charging (not auto) and like the idea,
and also agree the preference for diesel. Nice if it's portable -
but that means air cooling - usually noisier.

On the other hand, since we will be operating at only one speed, we can
optimize our noise reduction, so it will be quieter than a
variable-speed motor.

One factor you haven't mentioned is the desirability of charging
at the maximum feasible rate (minimum running time). Perhaps
you've already got that idea in mind.

Yes, the system is designed to operate at an optimal output power. It
should only start when the batteries are low enough to take a full
charge and shutdown when the load drops. It isn't designed to do
trickle or variable charging.

Just in case you haven't, I achieved best results charging by
taking my (European) 240v through an intelligent charger, one that
sensed battery voltage direct, and delivered up to 14.4v (variable
depending on battery type) stepping to 13.6v once the main charge
had been delivered (there was also a 16v option for de-sulphating
the batteries. Add water afterwards!).

This brings up another question; should we incorporate an intelligent
charger or should we interface with an existing external charger? If
your batteries are already connected to a charging system, it will only
confuse things if we try to operate two independent changing systems
simultaneously. My assumption is that most potential users of this
charger already have a charging system onboard. Is this a valid
assumption? I have no experience with off-the-shelf marine chargers,
can they even be interfaced with an external power source?


A shortcoming of most petrol gennys on the market which supply 12v
nominal is that they're usually regulated to 13.4v or so maximum,
which gives a very slow re-charge once you reach 75% or so of
battery capacity. Especially if you're pumping it down a long line
. . .

Because of the binary nature of our system, we don't intend on taking
the batteries to full charge, just to the point where they can no longer
take full charging current. This is the most efficient way to operate
our system since it is optimized to deliver a specific output power and
will lose efficiency at lower output levels.

--
Chuck Cox - SynchroSystems - Synchro.com
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