high-output alternator, with the added plus
of eventually cutting the charge voltage back
to a safer “float” level.
What the 25-percent rule is really
about is wasting money. A wet-cell battery
shouldn’t be charged at more than around
25 percent of its amp-hour capacity, so for
your 130-Ah battery, a 35- to 50-amp alternator delivers all of the power the battery
can accept. If you fit a 130-amp alternator,
the smart regulator may allow overcharging
for a short period of time (not particularly
good for the battery) and the high amperage
is going to drive the voltage up more quickly
so that the regulator switches into absorption at a lower actual charge level — sort
of a double whammy. Once the regulator
switches out of the bulk charge stage, you
are getting exactly the same charge profile
that you got before spending the money on
fast-charging equipment. The float feature is
worthwhile if you motor a lot, but otherwise
it, too, is a waste. Big alternators and smart
regulators are great when paired with a big
battery bank and typical cruising boat power
consumption, but this “upgrade” really isn’t
if your electrical system cannot take full
advantage of the extra capacity.
ignition-protected, meaning it’s capable of
producing a spark that may ignite gasoline
fumes. So if the GFCI is in a gasoline engine
space or a space with fuel lines, tanks, or
fuel line fittings, install the GFCI outside the
space and “daisy chain” it to a standard outlet downstream in the space. If you’re using
an inverter with the GFCI outlet, check
the owner’s manual. Many inverters have
specific manufacturer part numbers for the
GFCI due to the sine-wave produced; not
using a specified unit may result in nuisance
Other considerations are the connec-
tions. Don’t use the push-in connector on the
outlet! Use a captive terminal (such as a ring
terminal) on the screws on the side of the
outlet. Stranded wire isn’t made for those
I’m getting ready to install a 3-way valve between
the strainer and raw-water pump on the engine.
I’ve seen this before as a secondary bilge pump
when in an emergency situation. Can you offer
guidance on what, if any, particular valve to use?
Should any other changes be made to the cooling
system and/or exhaust?
MEET THE EXPERTS
KEEPING AHEAD OF THE HOSE
We just changed the line going from our head to
the holding tank. It was totally built up. Is there
anything we can put down the toilet to keep this
from happening again?
He’s been one of the most consulted experts on boat care and
upgrades for 30 years, and a panelist on our “Ask The Experts”
website for a decade. He and his wife cruise aboard their 30-footer
part of the year in the eastern Caribbean. His books include Don
Casey’s Complete Illustrated Sailboat Maintenance Manual, and the
recently updated This Old Boat, the bible for do-it-yourself boaters.
The VP/Technical Director for the American Boat & Yacht Council
(ABYC), John grew up boating. He’s been in the industry since
1990, with experience from a yacht brokerage and boatyard to
owning a marine supply store. He and his family sail their classic
1976 Irwin ketch, a boat he completely restored. John is a trusted
source for technical information for industry professionals.
TOM NEALE: There are several products
like Raritan’s CH. (CH stands for Cleans
Hoses.) It’s made specifically for this problem and is a relatively new product. It’s
not cheap, but in my opinion, it’s worth
it. See my discussion on: www.BoatUS.
He’s maintained, lived aboard, and cruised long distance on boats
with his wife and family for most of his adult life. He can take apart
and fix almost every system aboard a boat, has written two books,
filmed a two-set DVD on East Coast cruising, written for top marine
magazines, and has won seven first-place awards from Boating
Writers International and many awards for his technical writing.
The editor of Seaworthy, the damage avoidance newsletter of
BoatU.S. Marine Insurance, Bob has written hundreds of articles
on safety, loss prevention, and causes of boating accidents.
His 2006 book, Seaworthy, Essential Lessons of Things Gone
Wrong, is based on 20 years of real claims files. He’s owned
Folkboats to J-Boats and currently sails a 36-foot sloop.
HARDWARE STORE GFCI?
I need to replace the Ground Fault Circuit
Interrupter (GFCI) on my cruiser. Will a hardware store GFCI be OK, or are there special
marine models of GFCIs?
One of the most experienced technical writers in the marine business, and an accomplished fisherman, Lenny has a thorough
understanding of modern marine electronics on both technical and end-user’s levels. He’s written five books, and won 18
Boating Writers awards and two awards for excellence from the
Outdoor Writers Association. For several years running, he’s also
been selected as a judge for the NMMA Innovation Awards.
JOHN ADEY: Good news. A household
GFCI is fine as long as you consider ignition
protection. The GFCI off the shelf is not
CONTACT THESE AND ALL OUR EXPERTS AT WWW.BOATUS.COM/ASK
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