West Marine's Battery Switching advice
Bob Richardson
STRONG advice to replace the typical OFF-1-BOTH-2 battery switch with
three separate ON-OFF switches. This seems like a terrible waste of
money, time (installing), and precious space. Making such a
recommendation seems so ill advised that it undermines any other advice
from "The West Advisor."
From what I can gather, the principle reason is to avoid the following
mistake which seems to happen with regularity under this scenario.
Banks #1 and #2 can be used interchangeable for starting and house
loads. The skipper would switch to the BOTH position in order to have
"the full cranking power of the batteries". Then he/she would forget to
switch back to #1 or #2 once the hook was down, and thereby drain both
batteries.
Now, I admit that having an operating procedure which requires flipping
the Battery Switch is fraught with problems. Isn't the logical solution
to have engine starting capabilities with both battery banks, rather
than mess around with multiple switches?
Here's what I do, and I rarely ever flip the Battery Switch. Bank #1 is
my house bank. It includes 6 6-volt golf cart flooded batteries that
give me about 600 Amp-Hrs. They are relatively inexpensive. I can
easily get 6 summers of use out of them. This is a lot of "juice", but
it meets my needs, with DC refrigeration, ham radio, stereo, lights,
etc.
Bank #2 is a single Prevailer gel battery of about 80 Amp-Hrs that is
only used if the house bank doesn't have enough power left to start my
engine. Once a year I typically flip to BOTH while on a long motoring
run, in order to top off both battery banks. I have an Ample Power
regulator. The Prevailer can easily hold its charge for a full year.
I set the battery switch on #1 and leave it there.
Here's what I think the advantages are:
1. Peace of mind knowing that I will always be able to start the engine.
2. The house bank is the maximum size (rather than 2 equal size banks).
This means that I get the maximum power from the house bank, without
being tempted to switch over to the other bank for some more juice, and
thereby compromise my engine starting capability.
3. There are fewer "deep discharges" of the house bank, since I rarely
ever let the rested voltage in it drop below 12.10. With two equal size
banks, there would be more temptation to "use up" one bank before
dipping into your reserve supply on the other bank.
4. Golf cart batteries are far more economical than the "zero
maintenance" batteries.
The only disadvantage that I can see is the requirement to keep my
flooded batteries filled with distilled water. About once every other
month seems about right.
I'm always open to a better way of doing something. Any opinions out
there? Does the West Marine Advisor's advice really make sense?
Socalsail
On the next boat I am thinking of using the stock alternator for the engine
starting battery and a seperate 150 amp alternator for the house bank. One
on-off switch for the engine and one for the house bank. That way you never
forget to charge the engine start battery. The starting battery is only
conected to the engine. No other loads.
Lou W.
Bob Richardson <bo...@spamblocker.whidbey.com> wrote in message
news:39D63046...@spamblocker.whidbey.com...
as though one could still get juice from both battery's with the
three switch arrangement and a person could still forget to turn
those switches off resulting in the same problem that can occur
with a single 1-2-both-off switch. Sounds like they want to sell
extra switches.
I've pretty much solved my charging woes with a 45w solar
panel with a decent regulator. The starter battery is always full
as is the house bank. I do not have a refer though....just lights
and electronics. Water is via a foot pump.
Steve
that you "Once a year I typically flip to BOTH while on a long motoring run,
in order to top off both battery banks". You state that your Prevailer is a
Gel cell and your house bank is deep cycle golf cart batteries. Not a good
combination in parrellel while charging since the Gel cell has a very
diffterent charging characteristics.
The Gel Cell should be charged seperately from your deep cycle flooded cell
batteries.
Just my opinion.
Steve
s/v Good Intentions
Rich Mechaber
further step down in technology: the emergency start battery was
completely disconnected from all circuits, and once a month I connected
it up with big booster cables. You should probably consider topping off
your gel cell more often than annually, depending on how warm your
battery compartment gets.
The following was excerpted from
http://www.irdusa.com/BatteryMAX/what_is_a_battery.htm
under the section headed "Sealed Batteries"
"Lead-Antimony batteries have a much
higher self-discharge rate (2-10% per week)
than Lead or
Lead-Calcium (1-5% per month), but the
Antimony improves the
mechanical strength of the plates, which is an
important factor in
electric vehicles."
I don't know what type of gel cell is typically sold for the marine
market, but a better marine bettery of any electrolyte/chemistry type
will have stronger plates than one designed for land use.
Rich Mechaber
Bob Richardson wrote:
>
> While flipping through the West Marine 2000 catalogue, I noticed their
> STRONG advice to replace the typical OFF-1-BOTH-2 battery switch with
> three separate ON-OFF switches. This seems like a terrible waste of
> money, time (installing), and precious space. Making such a
> recommendation seems so ill advised that it undermines any other advice
> from "The West Advisor."
>
> From what I can gather, the principle reason is to avoid the following
> mistake which seems to happen with regularity under this scenario.
> Banks #1 and #2 can be used interchangeable for starting and house
> loads. The skipper would switch to the BOTH position in order to have
> "the full cranking power of the batteries". Then he/she would forget to
> switch back to #1 or #2 once the hook was down, and thereby drain both
> batteries.
>
> Now, I admit that having an operating procedure which requires flipping
> the Battery Switch is fraught with problems. Isn't the logical solution
> to have engine starting capabilities with both battery banks, rather
> than mess around with multiple switches?
>
Terry Spragg
starting cycle, you should'a fixed the engine before it failed.
Why have two systems where one should do? Murphy's rule, you should
have two ways to charge your starting battery, and an automatic
switch to fail. Hay! It's just a diode!
If an engine doesn't start right up, fix it, before you kill the
battery.
Engines are made to run. If they don't, don't fart around, fix it.
Then it will start right away. You should never need a deep cycle
on your starting battery. My engine draws about 40 amps to start,
and if it doesn't start right away, I fix it... Twenty minutes
later, everybody poles off the rocks while putting on their
parachute. Niagra falls is such a lovely spot...
-Usually by tapping really fast on the the float housing or choke
with a rubber hammer in just the right spot (actually, I pull the
spade connector on the fuel pump, then start it up) then I reconnect
the fool pump.
I'm serously considering a fully electric propulsion system. Ok,
I'm over it.
Terry K
Eugene Gruender
>
> Thats the way I had it on my boat, and never had a problem. Nice and simple.
> On the next boat I am thinking of using the stock alternator for the engine
> starting battery and a seperate 150 amp alternator for the house bank. One
> on-off switch for the engine and one for the house bank. That way you never
> forget to charge the engine start battery. The starting battery is only
> conected to the engine. No other loads.
That is exactly what I have, it's been that way for about 6 years and
works fine. There are pictures at:
http://www.geocities.com/TheTropics/Cabana/7414/alt.html
Gene Gruender
Rainbow Chaser
Bob Richardson
Socalsail wrote:
> Thats the way I had it on my boat, and never had a problem. Nice and simple.
> On the next boat I am thinking of using the stock alternator for the engine
> starting battery and a seperate 150 amp alternator for the house bank. One
> on-off switch for the engine and one for the house bank. That way you never
> forget to charge the engine start battery. The starting battery is only
> conected to the engine. No other loads.
The goal is maximum safety with simplicity. Two alternators vs. one is not a
step in that direction. My point is, there is no need for a separate engine
start battery. You never forget to charge the engine start battery if there is NO
separate engine start battery. The engine and all other electrical needs should
use the same battery bank. The second battery bank, in my recommendation, is
only used in an emergency - when you can't start the engine with the first bank.
Being a gel cell battery, you don't have to worry about recharging bank # 2 more
than once a year (in my experience).
Lew Hodgett
"Bob Richardson" <bo...@spamblocker.whidbey.com> wrote in message
news:39D63046...@spamblocker.whidbey.com...
> STRONG advice to replace the typical OFF-1-BOTH-2 battery switch with
> three separate ON-OFF switches.
> Does the West Marine Advisor's advice really make sense?
Yep.
Lew
Roger Leaman
"Lew Hodgett" <lewho...@earthlink.net> wrote in message
news:9y4C5.1375$rO1....@newsread1.prod.itd.earthlink.net...
> > STRONG advice to replace the typical OFF-1-BOTH-2 battery switch with
> > three separate ON-OFF switches.
> <snip>
> > Does the West Marine Advisor's advice really make sense?
My Bavaria sailing boat (as built) has a single battery switch on the ground
(negative) circuit for the 2 batteries and they are charged from a single
alternator through split charge diodes. This way there is only one switch to
isolate both batteries and charging for each is isolated by the diodes.
Seems like a sensible arrangement to me!
Roger
(Playtime - Bavaria 38 Ocean)
Peter Kennedy
although I wouldn't credit West with inventing it. In principle it gives two
separate battery banks, one for starting and one for house, each with
appropriate battery types and sizes for their use, and no connection between
the two except for an emergency switch which I call a "jump start switch"
You can remove one battery switch if you like by making one of the switches
a 1/2/both/off switch but I have found that by just making three simple
on/off switches the system is easier to understand. You can make the major
charging sources (alternator etc.) go to the house bank where the major
loads are. Make this a deep cycle battery bank of as big a capacity as you
can accommodate. You then have to figure out some way of charging the start
bank, which only gets used for starting, and should be a cranking battery
with a suitable Cold Cranking Amps rating to start your engine.
This layout is vastly superior to the way that most production boats come,
with two equal battery banks, so that one of the banks is usually sitting
around almost idle, being held in reserve for starting.
--
Peter Kennedy
Peter Kennedy Yacht Services
Marine Electrical Systems
http://www.pkys.com
Bob Richardson wrote in message
<39D63046...@spamblocker.whidbey.com>...
>While flipping through the West Marine 2000 catalogue, I noticed their
>STRONG advice to replace the typical OFF-1-BOTH-2 battery switch with
>there? Does the West Marine Advisor's advice really make sense?
>
>
Paul Turner
seems to work very well. Having the engine and the house banks totally
segregated is great for mental health!
BTW, we retained the old '1-2-both' switch for the engine bank (providing your
'jumpstart' capability and added a large circuit breaker/switch for the house
bank.
Phillip Coker
1. Left the two deep-cycle batteries connected to the Off-1-Both-2 switch in
original configuration.
2. Installed a starting battery in the battery locker with a separate on-off
switch for it and moved the starting cable from the bus on the Off-1-Both-2
switch to the new On-Off switch.
3. Installed a three-bank isolator and moved the alternator wire from the
bus on the Off-1-Both-2 switch to the isolator. Ran a separate wire from the
isolator to each battery positive terminal.
4. For shore-power AC charging, I have a three-bank charger with a separate
wire to the positive terminal of each battery.
There is no connection between the starting battery and the house batteries.
Adding another On-Off switch between the Off-1-Both-2 switch and the
starting battery On-Off switch would give more flexibility, of course, and I
am considering it.
The alternator line does not go through a switch so there is little danger
of inadvertently unloading the alternator.
To keep from taking either battery 1 or battery 2 all the way down, I switch
between them every so often. Actually, I've been switched to battery 1 for
over a month now.
Have been using this system most of this season and it is working
beautifully. That little Yanmar just fires right up instantly at the touch
of a button every time.
Phillip Coker
Silent Dancer
Hunter 29.5
Bill Amado
> ...snip
> 4. For shore-power AC charging, I have a three-bank charger with a separate
> wire to the positive terminal of each battery.
It was my plan to do this too, until I discovered that, although the
charger (a Statpower in my case) has 3 DC outputs, it only senses the
voltage of one of the banks and uses that to determine the charge
program for all three outputs. In my case I was sensing two 4D AGMs and
sending output 2 to an Optima start battery. I was concerned that I was
going to fry the Optima so I disconnected it from the charger. I spoke
to the people at Statpower to confirm my suspicion that I had this
straight and they said yep, and suggested a separate small charger for
the start battery. I didn't do that but went with an Echocharge.
dave
batteries for a house bank and a smaller battery for the engine start.
The key to making this systemm really work is a solenoid switch that
parallels the two banks when the engine is running. You just turn on the
two banks when you step on the boat and they are isolated untill the
engine runs, then the alternator tops off all the batteries.
dave
Strbrdtac
advice, several folks like Jack Rabbit Marine have been making similar
suggestions years before West Marine decided this might be a good set up.
After ripping out the ONE/TWO/BOTH switch, we now have one large house bank
with an On/OFF switch, one starter battery with its own ON/OFF switch. Both
systems are basically separate, but when charging, a solenoid will connect
them. If necessary, I can manually connect both banks, but this has never been
needed.
You cannot start the engine without turning on the starter battery. (This
switch is not located near the main panel, and might be a bit more difficult
for a thief to find.) The alternator has a "zapper" to protect the diodes, but
it is highly unlikely that there will be no battery connected to its output
when the engine is running.
This system has served us well for nearly six years, a goodly part of living
aboard.