Battery charging
 

"Thom Stewart" wrote in message
...
John,

I have to agree with you. After years of using single batteries for
starting and running and other for House Battery and a single for
Inverter, I finally learned to start on two and run on both; just like
my truck camper. My Inverter wasn't hooked up to the battery switch so
that did need special attention. I've since done away with the Inverter
battery and paralleled it inverter with the house battery. They all get
the same charge. Works for me and cleaned up the wiring.

http://community.webtv.net/tassail/ThomPage

What I have found works well is to have a third battery (i.e., a starting
battery optimized for engine cranking as opposed to deep discharge) that is
on its own on/off switch, located as close to the engine as possible for a
short cable run and with significantly sized cable. (I'm using #00.) I only
turn this on for starting and for about the first 15 or 20 minutes of engine
running time (to make sure it gets topped back off after starting the
engine.) Then, I set my two Group 27 house batteries to the "Both" (i.e.,
paralleled) position and switch off the starting battery. (Important to do
it in that order so as not to fry the alternator diodes.) These Group 27's
are identical batteries of the same age and have always been run in parallel
so (hopefully) they have been discharging/charging at more or less the same
rate. Plus, by always running them in parallel I tend not to suck either
battery down too low, as opposed to, for example, seriously depleting
battery #1 and then switching to battery #2.

Regards,
Alan Gomes

Battery charging
 

OzOne wrote:
That's why we have switches that make before break.


A good idea, but most of the simple & cheap battery switches
don't even pretend to do this. Many of the expensive ones
that claim to, don't. It's a fairly simple thing so I don't
know why that is... may be different down your way.

DSK

Battery charging
 

Mys Terry wrote:
.... If you believe what Oz just posted, you'll have learned
something that you didn't know.

No danger of that happening with you

DSK

Battery charging
 

"John W. Bienko" wrote in message
...
What is the recommended procedure..
Start with Battery #1 or
Star with Both Batteries switch ON

THanks
JWB

Some battery switches are designed to allow switching between banks while
the engine is running, others are not. I would suggest you contact the
manufacturer and find out about your particular model. If yours is the type
that must be switched to another bank while the engine is off, then I would
say start with your starting bank, charge it up, then turn off the engine
after it is warmed up and switch to "both", restart your engine warm
(easier) and charge both banks. This can be repeated to charge the second
bank alone as well after the "both" sequence.
I would advise you look into battery isolators and a battery condition
monitor. Hope that helps.

Deck Gorilla

Battery charging
 

"Dave" wrote in message
...
On Sat, 03 Jun 2006 23:13:31 GMT, "John Cairns"
said:

Or that you forget to switch the batteries after the engine is started,
and
don't charge either battery properly, overcharging one battery and
undercharging the other.

Why do you think that not charging the second battery will result in
overcharging the first? I would have thought that a well built system
would
prevent overcharging even if you had only one battery.

You can not overcharge a battery with a properly functioning alternator.

Deck Gorilla

Battery charging
 

"Mys Terry" wrote in message
...
On Sun, 04 Jun 2006 14:04:09 GMT, "silverback"
wrote:

You can not overcharge a battery with a properly functioning alternator.

Wanna bet?

Enlighten me. From my experience on a multiude of vessels as crew, running
for hours and even days on both gas and diesel axilliary, I have never heard
of a battery begining overcharged by operation of an engine for extended
durations. I have been informed by many people that such an incident could
not occur with a properly functioning alternator. Maybe you have experience
to contradict this? If so, I would be interested in the conditions and
siuations that led you your conclusions.

Deck Gorilla

Battery charging
 

Ozone wrote ...
.
IOW, You could motor your sailboat a dozen times around
the world

Why would he do that, it's a SAILboat?

S

Battery charging
 

"silverback" wrote in message
news:tLBgg.8127$771.3210@edtnps89...

You can not overcharge a battery with a properly functioning alternator.

Deck Gorilla

"In typical automotive use we have a thin plate cranking battery that is
rarely discharged by more than a small percentage of it's capacity. The act
of cranking draws the charge from the surface of the plates, which are then
recharged before the battery has time to equalize internally-the inner
plates retain their charge. In general, the engine and alternator run far
longer than is needed to replace this charge. Little charge is needed; it
has to be applied only to the surface areas of the plates; and we have
excess charging time. In this undemanding environment voltage regulator
settings are kept deliberately low in order to avoid damaging the battery
through overcharging during extended periods of engine running time.

In contrast, in many marine applications a thick-plate deep-cycle battery is
deeply discharged over a long period of time, allowing the battery to
equalize internally and so draining the charge from the inaccessible
inner-plate areas. The engine and alternator are then run for far less time
than is needed to restore a full charge. If a typical automotive regulator
voltage setting of around 14.0 volts(for a 12 volt system) is used during
charging, the rising surface voltage of the battery will cause the regulator
to curtail alternator output soon after the battery is 50% charged, which is
well before battery safety demands that it be cut back. This unnecessarily
prolongs charging times.

Since a well designed deep cycle battery bank will be cycling primarily in
the region of 50% to 80% of full charge, a typical regulator cripples
charging performance in the region of interest to boat owners! As a result,
many batteries are perennially undercharged, and die prematurely from
sulphation. In addition, if battery charging is accomplished by running the
boat's main engine at anchor, the engine will run long hours at low loads to
little effect, except to increase wear, tear, and maintenance.

In these circumstances the charge rate needs to be accelerated to the limit
the batteries can accept, driving the voltage(pressure) as high as can be
tolerated, so that the inner plate areas will be charged as rapidly as
possible. But if a regulator's voltage setting is raised to produce the
maximum safe charge rate in the 50% to 80% of full charge region, during
extended periods of engine running the batteries will be overcharged. This
will result in an excessive loss of electrolyte, destruction of the positive
plate grids, and perhaps overheating and buckling of the battery plates.

The dilemma is clear. In many pleasure boat situations, batteries are
periodically discharged deeply (to at least the 50% level), but charging
times are restricted. Thus, fast charges are required, which calls for
higher voltage regulator settings than in automotive applications; otherwise
the batteries will suffer from undercharging, sulphation, and a permanent
loss of capacity. But if voltage regulator settings are raised, extended
engine running will likely overcharge the batteries, causing excessive
gassing and plate damage".

Nigel Calder

"Boatowner's Mechanical and Electrical Manual"

The key, IMHO, is how batteries discharge and accept charges.

John Cairns

Battery charging
 

"Scotty" wrote in message
...

Ozone wrote ...
.
IOW, You could motor your sailboat a dozen times around
the world

Why would he do that, it's a SAILboat?

I believe Ozone is attempting to make it comprehendable to Capt. Rob. It's a
good thing Heart of Gold has an infinity drive.

Deck Gorilla

Battery charging
 

OzOne wrote in message ...
On Sun, 04 Jun 2006 01:32:36 GMT, "John Cairns"
scribbled thusly:


OzOne wrote in message
. ..
He didn't mention having a "well built system", simply a typical 1-2 All
battery selector switch, which does nothing to regulate charge. I would
have
thought that if he had a "well built system" he would have nmentioned it
and
indeed, probably never have asked the question in the first place, as he
would have had no need to. Which reminds me of the fact that I don't
have
a
"well built system" on my own boat, possibly a project to tackle this
year.

John Cairns

John, the regulator regulates charge.
When a battery is charged it simply stops charging....what would you
do after all batteries were charged and yet you still needed the
engine....Unplug wires?


Oz1...of the 3 twins.

I welcome you to crackerbox palace,We've been expecting you.

"Boatowner's Mechanical and Electrical Manual"

Good section on battery charging, with brief and easy-to-understand
explanations as to how alternators/batteries work in both
automotive/marine
applications, the differences between those two very different types of
alternators. In a nutshell, automotive alternators/regulators are designed
to charge batteries that are never typically deeply discharged, marine
alternators/regulators are designed to charge deep cycle batteries that
are
typically discharged to half of their capacity. You might note the term
alternator/regulator, we're talking about a typical automotive or marine
alternator that has an integrated regulator, not a seperate regulator like
those made by Heart or Ample Charge as part of a proper charging system on
a
sailboat. Suggest you buy the book, hours of reading on
mechanical/electrical systems on boats, with an emphasis on sailboats, at
least that's my impression, though it could simply be bias.

John Cairns

Yes John, you do have a regulator so it is just not possible to
overcharge a battery unless there is a problem with that regulator.
IOW, You could motor your sailboat a dozen times around the world with
the battery switch set to one bank and never overcharge that bank.


Oz1...of the 3 twins.

I welcome you to crackerbox palace,We've been expecting you.

"In typical automotive use we have a thin plate cranking battery that is
rarely discharged by more than a small percentage of it's capacity. The act
of cranking draws the charge from the surface of the plates, which are then
recharged before the battery has time to equalize internally-the inner
plates retain their charge. In general, the engine and alternator run far
longer than is needed to replace this charge. Little charge is needed; it
has to be applied only to the surface areas of the plates; and we have
excess charging time. In this undemanding environment voltage regulator
settings are kept deliberately low in order to avoid damaging the battery
through overcharging during extended periods of engine running time.

In contrast, in many marine applications a thick-plate deep-cycle battery is
deeply discharged over a long period of time, allowing the battery to
equalize internally and so draining the charge from the inaccessible
inner-plate areas. The engine and alternator are then run for far less time
than is needed to restore a full charge. If a typical automotive regulator
voltage setting of around 14.0 volts(for a 12 volt system) is used during
charging, the rising surface voltage of the battery will cause the regulator
to curtail alternator output soon after the battery is 50% charged, which is
well before battery safety demands that it be cut back. This unnecessarily
prolongs charging times.

Since a well designed deep cycle battery bank will be cycling primarily in
the region of 50% to 80% of full charge, a typical regulator cripples
charging performance in the region of interest to boat owners! As a result,
many batteries are perennially undercharged, and die prematurely from
sulphation. In addition, if battery charging is accomplished by running the
boat's main engine at anchor, the engine will run long hours at low loads to
little effect, except to increase wear, tear, and maintenance.

In these circumstances the charge rate needs to be accelerated to the limit
the batteries can accept, driving the voltage(pressure) as high as can be
tolerated, so that the inner plate areas will be charged as rapidly as
possible. But if a regulator's voltage setting is raised to produce the
maximum safe charge rate in the 50% to 80% of full charge region, during
extended periods of engine running the batteries will be overcharged. This
will result in an excessive loss of electrolyte, destruction of the positive
plate grids, and perhaps overheating and buckling of the battery plates.

The dilemma is clear. In many pleasure boat situations, batteries are
periodically discharged deeply (to at least the 50% level), but charging
times are restricted. Thus, fast charges are required, which calls for
higher voltage regulator settings than in automotive applications; otherwise
the batteries will suffer from undercharging, sulphation, and a permanent
loss of capacity. But if voltage regulator settings are raised, extended
engine running will likely overcharge the batteries, causing excessive
gassing and plate damage".

Nigel Calder

"Boatowner's Mechanical and Electrical Manual"

The key, IMHO, is how batteries discharge and accept charges.

John Cairns