[C320-list] Basic hot water heater and charging question

[jackbrennan]

Gene:
Read Nigel Calder for a better explanation, but it's not necessarily a problem.
A high output alternator does not keep, say, 90 amps for very long. The charge rate drops quickly because batteries accept limited amounts of charge, depending on their type.
The voltage reading will drop as the charge rate drops.
Alternators also experience voltage drops when they heat up. 
The big questions: What does "and change" mean? 13.6 sounds normal. 13? Maybe not. Is your battery bank being charged satisfactorily?
There's your proof.

As others have noted, you can get a new stock alternator for a 3gm30 for about $80 on the Internet.
Jack BrennanSonas, 1998 Catalina 320, no. 528Tierra Verde, FL.







Sent from Yahoo Mail on Android 
 
  On Sat, Sep 15, 2018 at 8:39 PM, Gene Helfman<genehelfman at gmail.com> wrote:   Thanks, guys.  We hoped the water heater used engine heat, but I couldn't
find the plumbing involved so assumed it was independent.  Makes sense to
make use of engine heat (sort of like cooking a chicken under the hood of
your car on a road trip, or am I showing my age).  WRT the
alternator.voltage regulator issue, obviously it's something we have to
check when we get home (we're cruising in British Columbia right now, end
of a 5 week trip). PO put in a different, much bigger alternator, so it's
going to require some expertise.  We put a meter on it and got full (like
14.85 V) out of it for a half hour, then dropped down to 13 and change.

On Sat, Sep 15, 2018 at 5:06 PM Troy Dunn <troutwarrior at gmail.com> wrote:

> Gene
>
> Sorry, should have added the following.  Assuming you are correctly
> surmising that the alternator output is dropping after 30 minutes, Either
> your voltage regulator or your alternator is malfunctioning.  If you have
> the stock alternator it is internally regulated.  You can get a
> replacement alternator pretty cheap, assuming you are happy with your
> current DC power set up.
>
> Cheers
>
> Troy
>
> On Sat, Sep 15, 2018 at 7:59 PM Troy Dunn <troutwarrior at gmail.com> wrote:
>
> > Gene
> >
> > The water heater is heated by the engine when motoring, and by shore
> power
> > when at the dock.  The heater is AC power only.  I think those heaters
> > draw about 1500 Watts...so that's about 125 amps if using a DC
> source...not
> > really feasible on our boats.
> >
> > Troy Dunn
> > Wonky Dog
> > Hull #514
> >
> > On Sat, Sep 15, 2018 at 7:52 PM Gene Helfman <genehelfman at gmail.com>
> > wrote:
> >
> >> Very basic: from where does the hot water heater draw electricity?  Is
> it
> >> off the battery bank?  The alternator? The battery when the alternator
> >> isn't charging?
> >>
> >>  I ask because we are having alternator problems when motoring.  Or
> maybe
> >> voltage regulator problems.  We get full charging for 30-35 minutes
> >> regardless of battery state, then it shuts off, meaning we are then
> >> drawing
> >> from the house 4Ds. When we shut the engine off (an hour or more later),
> >> we
> >> have lots of hot water. We're concerned that once the alternator shuts
> >> off,
> >> the water heater is still drawing power until the WH thermostat shuts it
> >> down.
> >>
> >> If so, is there an easy way to turn the hot water heater off.  It isn't
> an
> >> obvious toggle on the instrument panel.
> >>
> >> thanks,
> >> gene
> >> Satori, #398, 1997
> >> --
> >> Gene Helfman, Professor Emeritus
> >> Odum School of Ecology, University of Georgia
> >> PERMANENT address:
> >>    498 Shoreland Dr., Lopez
> >> <https://maps.google.com/?q=498+Shoreland+Dr
> .,+Lopez&entry=gmail&source=g>
> >> Is., WA 98261
> >>    (360) 468-2136
> >>    genehelfman at gmail.com
> >>
> >> *Zero tolerance is great for building airplanes but not for running
> >> countries.*
> >>
> >
>


-- 
Gene Helfman, Professor Emeritus
Odum School of Ecology, University of Georgia
PERMANENT address:
    498 Shoreland Dr., Lopez Is., WA 98261
    (360) 468-2136
    genehelfman at gmail.com

*Zero tolerance is great for building airplanes but not for running
countries.*