[C320-list] Inverter - follow-up questions

[crashley at gte.net]

Dean,

I'm not sure anyone answered this but here's one for you.

An inverter converts 12 VDC from the battery to 115 VAC @ 60 Hz (in the
U.S.) for the AC loads like a microwave. Most inverters also provide a
battery charging function when they have an external source of AC (like at
the dock).

The generator option (which I don't have) has the advantage that (when it is
running) it provides 115 VAC for the AC loads and can run the on-board
battery charger as well. It's true that running the boat's engine does this
too, but the efficiency of the generator is probably better. The generator
also uses a different fuel, gasoline, which you probably need on the boat
anyway if you have a gasoline engine for the dinghy outboard. Cost-wise I'm
not sure which one is better but inverter/chargers cost upwards of $1000
(sometimes a lot more) and also usually require some additional heavy gauge
DC cabling to be added depending on where you locate it. The external
generator is more of a "plug and play" approach. 

CR Ashley
Rosebud C320 Hull #882
  

 

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Dean Vermeire
Sent: Wednesday, March 04, 2009 9:32 AM
To: C320-List at Catalina320.com
Subject: [C320-list] Inverter - follow-up questions

Hi again.

Thanks for all the good input so far.  I hate to ask really stupid
questions, but somebody's got to do it.

It seems to me that I've got two choices - put in an inverter that takes DC
from the batteries and runs them down while converting to AC, or put in a
generator that uses some other energy source to run a motor that generates
AC.  I look at the existing systems onboard, and I see a diesel motor that
runs an alternator that produces DC to recharge my batteries.  I also have
shore power (AC) that recharges the batteries by way of a battery charger,
which I see listed in catalogs as a "battery charger / inverter".

Stupid question #1:  Are they calling the battery chargert an inverter
because it is changing AC to DC?
Stupid question #2:  Why is a generator less expensive than a DC-to-AC
inverter, when the generator must have similar circuitry in it?

Thanks,
Dean Vermeire
Moonstruck II (#847)