[PUP] PPM Electrical Generation and storage

[bob Austin]

What is an ADM battery?  For the majority of passagemakers the weight of
batteries is inconsiquential.  The weight can be distributed down low--I have
voyaged many thousands of miles in a vessel which had a box keel--over 3 feet
wide--where the batteries were down in the keel (precautions were taken to
prevent sea water from getting to them)--and acted as ballast.

When running the main engine, generation capacity is not an issue; but at
anchor, which is the majority of time, even  in most passagemakers,  running a
large gen set several hours a day can accomplish all of the chores necessary.
These include running a compressor to pull holding plates down, a water maker,
water heating, and generation of DC power (it does not make much difference if
it is from an alternator on the genset, or battery chargers--we used a
combination of 150 amp alternator and 130 amp battery charger.   However, it
seems like many modern passagemakers need the luxary of air conditioning.
Although there are air conditioning units which can run on  DC power, and
perhaps more effecient units using chilled water, it still remains a problem
to provide adequate airconditioning.  (We voyaged in motor sailors, and never
required air conditioning in any parts of the world--as long as there was a
breeze)  Many power passagemakers do not have adequate ventillation.  An
example of this problem was the Nordhavn 40 around the world.   As I
recollect, the original plan was no generator and minimal AC off the
inverter--but reality set in, and the Generator had 2776 hours compared to the
mains 4697 hours.  Unfortunately I cannot pull up on the Nordhavn site the
comments or forum about the air conditioner (only the later material was
available).

Bob Austin