Battery Meter

16 Volts is overcharging, and continued use will quickly destroy the battery.
The first guess would be bad wiring to the regulator, or maybe a bad regulator.
Before you do anything, check the water level in the battery - if you've been
running like this its likely down. If everything looks OK, you should check
with a digital meter to verify the voltage. Normally, regulators are set for
14.2 to 14.5 volts, and anything over 14.7 is considered overcharging. If it
really is 16 Volts, don't continue running it.

BTW, at 16 volts you should be able to smell the battery "cooking."





"Ernie" <1racabli.TakeThisOut@maine.rr.com> wrote in message
news:Lcnqc.272571$e17.107600@twister.nyroc.rr.com...
 > Is it normal for the battery gauge to read 16 when the boat is in
 > operation? The gauge only goes up to 18. The battery will be a year old
 > next month. Should I be concerned?
 >
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Battery Meter 

Ernie wrote:
 > Is it normal for the battery gauge to read 16 when the boat is in
 > operation? The gauge only goes up to 18. The battery will be a year old
 > next month. Should I be concerned?

You should get an accurate measure of what the charging voltage is that
the alternator is putting out.

It sounds like your gage is showing 16 volts, but dashboard gages are
notoriously inaccurate. Can you put a multimeter on the battery
terminals when in operation? As somebody else posted, the voltage should
not be more that 14 or 14.2 tops.

Fair Skies
Doug King<!-- ~MESSAGE_AFTER~ -->
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Ernie wrote:

 > Is it normal for the battery gauge to read 16

If the 16 volts displayed is accurate it is a bit too high for
continuous charging of a lead acid battery, that is the "equalizing"
voltage. Check the charging voltage with a good quality voltmeter before
you start changing things because the cheap panel meters supplied with
consumer grade boats are not known for their accuracy.

If you have access to the battery while running and the battery is a wet
cell with removable cell covers (where you add water) look and see if
the cells are bubbling. If there are a lot of bubbles and/or you have
been adding a lot water then your charging voltage is probably high.

Rick<!-- ~MESSAGE_AFTER~ -->
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Here you go

<a style='text-decoration: underline;' href="http://www.solectria.com/products/amphrm.html" target="_blank">http://www.solectria.com/products/amphrm.html</a>


DSK <dsk.DeleteThis@dontbotherme.com> wrote in message news:<c3oqc.323$YB6.311@bignews3.bellsouth.net>...
 > Ernie wrote:
  > > Is it normal for the battery gauge to read 16 when the boat is in
  > > operation? The gauge only goes up to 18. The battery will be a year old
  > > next month. Should I be concerned?
 >
 > You should get an accurate measure of what the charging voltage is that
 > the alternator is putting out.
 >
 > It sounds like your gage is showing 16 volts, but dashboard gages are
 > notoriously inaccurate. Can you put a multimeter on the battery
 > terminals when in operation? As somebody else posted, the voltage should
 > not be more that 14 or 14.2 tops.
 >
 > Fair Skies
 > Doug King<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Battery Meter 

Also Sprach Ernie <1racabli RemoveThis @maine.rr.com>:
 > Is it normal for the battery gauge to read 16 when the boat is in
 > operation? The gauge only goes up to 18. The battery will be a year old
 > next month. Should I be concerned?

Regardless of the other replies, there are circumstances where charging
a charging voltage of 16-17 volts is perfectly normal and
expected. Specifically, many many older outboard engines, and even a few
newer but down-market ones, have low current unregulated charging
systems... in other words, they had a rectifier but no voltage
regulator. Since they are low current, topping out at 6 or 8 amps, they
typically won't fry your battery, so long as you make sure the water level
is topped up. Now, if you have an inboard or stern
drive, or a newer outboard with a regulated charging system, I'd do some
troubleshooting, starting by measuring the voltage at the battery with a
good digital voltmeter.

Dan

--
It's good to drink. It's good to laugh. But try to both at the same time
and you'll pay through the nose.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Battery Meter 

"Ernie" <1racabli.TakeThisOut@maine.rr.com> wrote in message
news:Lcnqc.272571$e17.107600@twister.nyroc.rr.com...
 > Is it normal for the battery gauge to read 16 when the boat is in
 > operation? The gauge only goes up to 18. The battery will be a year old
 > next month. Should I be concerned?

Ernie - More accurately, this is a volt meter, not a battery gauge. This is
nit-picky, yes, but an important distinction. When the motor's running, it
measures the output of the charging system, not the state of the battery
itself. Therefore, it's not the battery that is possibly "wrong" it's the
charging system. I say "possibly wrong" because...

As others have mentioned, the first guess is that your dashboard gauge is
inaccurate. You can test the battery, charging system, and therefore the
gauge, by getting a decent digital multimeter. The meter doesn't have to be
expensive, but I recommend digital because they're easier to read. Set it
to the volts DC scale, and test the charging system by putting the
multimeter leads on the main battery cables while the motor is running. As
mentioned, it should read "around" 14 volts (13.8-14.2).

When the engine is stopped, the meter (and your dash gauge) would simply
test the output of the battery itself. A fully charged 12 volt battery is
12.6 volts. This varies a little higher if it's freshly charged (it will
"settle" at 12.6). But, if it's actually at 12 - it's almost dead.

You can get a very cheap, little tester that will indicate (with various
colored LED's generally) if the charging system and/or battery is good or
bad. These LED's are, of course, set to indicate the ~14 threshold for the
charging system and the ~12.6 volt threshold for the battery itself. But a
multimeter is a handy tool to have and worth spending a few bucks on. I
carry the little cheap tester in my small tool box though.

Beyond that, I don't know how to trouble shoot or fix. I don't know from
rectifiers, stators, regulators, etc. But if you find that the multimeter
shows a good charging voltage of around 14 when the engine is running, you
can be pretty sure your gauge is bad, and you need to buy a new gauge. You
can find a lot of options on line from OEM to aftermarket and should be able
to exactly, or closely match your existing gauges. I'd suggest you
temporarily test the gauge before actually installing it. Gauge
installation is a pretty easy DIY if you're so inclined.

Cam<!-- ~MESSAGE_AFTER~ -->
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Ernie, the best way to test a batter is with a load tester that uses a
carbon pile, but only shops would have that equipment. Autozone used to test
your battery for free with one, maybe they still do.

The voltmeter test is a good one to use on a battery, without the engine
running. Another poster said that the "voltage will settle down" after a
while....this is called a surface charge, what you get from a battery just
after it has been fully charged. It'll throw the VM test off. To remove the
surface charge, crank the motor for 15-30 seconds.

Another good test for a regular lead-acid battery is the electrolyte test.
It's a glass eye-dropper, you check each cell individually, and that way you
can tell if you have any bad cells. I can't remember the pass/fail,
something like if there are two cells that are bad, then the battery is
trash, or if two adjacent cells are bad....I can't remember. But the
electolyte test will tell you if your battery is bad.

Drew


"Ernie" <1racabli RemoveThis @maine.rr.com> wrote in message
news:Lcnqc.272571$e17.107600@twister.nyroc.rr.com...
 > Is it normal for the battery gauge to read 16 when the boat is in
 > operation? The gauge only goes up to 18. The battery will be a year old
 > next month. Should I be concerned?
 >
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Battery Meter 

 >A fully charged 12 volt battery is
 >12.6 volts.

13.2

2.2 volts X 6 cells equals 13.2<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Battery Meter 

"Gould 0738" <gould0738 DeleteThis @aol.com> wrote in message
news:20040519164213.24150.00000156@mb-m27.aol.com...
  > >A fully charged 12 volt battery is
  > >12.6 volts.
 >
 > 13.2
 >
 > 2.2 volts X 6 cells equals 13.2


This is an often debated subject, because it depends on the type of battery,
temperature, aging, etc. In general for lead acid batteries:

Open circuit voltage Charge in %
12.6V and higher 100%
12.4 - 12.6V 75 - 100%
12.2 - 12.4V 50 - 75%
12.0 - 12.2V 25 - 50%
11.7 - 12.0V 0 - 25%
11.7V and less 0%


Eisboch<!-- ~MESSAGE_AFTER~ -->
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"Gould 0738" <gould0738.RemoveThis@aol.com> wrote in message
news:20040519164213.24150.00000156@mb-m27.aol.com...
  > >A fully charged 12 volt battery is
  > >12.6 volts.
 >
 > 13.2
 >
 > 2.2 volts X 6 cells equals 13.2

Nonsense. You obviously have never actually used a voltmeter on a boat. The
"open circuit voltage" varies a bit with the technology, but will generally be
between 12.6 and 12.8. It may read a tad higher after charging, but settles in
a few hours.

<a style='text-decoration: underline;' href="http://www.trojanbattery.com/customercare_batterymaint4.html" target="_blank">http://www.trojanbattery.com/customercare_batterymaint4.html</a><!-- ~MESSAGE_AFTER~ -->
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Gould, it's 2.1 x 6, you get 12.6.


"Gould 0738" <gould0738 DeleteThis @aol.com> wrote in message
news:20040519164213.24150.00000156@mb-m27.aol.com...
  > >A fully charged 12 volt battery is
  > >12.6 volts.
 >
 > 13.2
 >
 > 2.2 volts X 6 cells equals 13.2<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Battery Meter 

On Wed, 19 May 2004 17:09:07 -0400, "Eisboch" <r_erikss RemoveThis @bellsouth.net>
wrote:
 >This is an often debated subject, because it depends on the type of battery,
 >temperature, aging, etc. In general for lead acid batteries:
 >
 > Open circuit voltage Charge in %
 > 12.6V and higher 100%
 > 12.4 - 12.6V 75 - 100%
 > 12.2 - 12.4V 50 - 75%
 > 12.0 - 12.2V 25 - 50%
 > 11.7 - 12.0V 0 - 25%
 > 11.7V and less 0%

==============================

Debated indeed, but that seems a wee bit harsh to me on the low end.
I routinely run my deep cycles down to 11.5 under moderate load and
they still have lots of juice left at that level, more than enough to
start the engines for example. I've always regarded 11.5 volts as the
50% mark where you really should recharge but don't necessarily need
to. A battery discharged to that level should be recharged ASAP of
course.

Regarging Chuck's 13.2 volts, that is about the right voltage for
"floating" a fully charged battery, but the battery will soon drop
back to 12.6 or 12.7 once the float charger/battery eliminator is
turned off.<!-- ~MESSAGE_AFTER~ -->
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 >Gould, it's 2.1 x 6, you get 12.6.

If it were 2.1, you'd get 12.6. Corect.

However, the potential capacity of a cell is
2.2 volts.

Consider the "Ideal Charge Curve" described by Rick Proctor of Cruising
Equipment Co:

Bulk phase: Chare at a rate up to 20-40% of amp-hour capacity to a voltage of
about 14.4 volts. (Gel: 14.1). For example, a 200 amp-hour battery would be
charged at 40-80 amperes. This will bring the battery to about 75% of full
charge.

Aceptance phase: Maintain battery at 14.4 volts (Gel, 14.1) while the amperage
is steadily reduced. This restores the next 25% of capacity at a declining
rate. Your battery can be considered fully charged if it will accept current
equal to 2% of cpacity at 14.4 volts. Example: A 200 amp hour battery accepts
only 4 amps at 14.4 volts.

Float phase: The voltage is reduced to 13.3 volts, (gel 13.7 volts) to maintain
the battery without losing electrolyte from the cells. *THIS IS A MAINTENANCE
PHASE, NOT A CHARGING PHASE*

If you test a battery aboard a boat and it reads only 12.6, it is not fully
charged.
Fully charged to "float phase" is over 13 volts for flooded batteries and 13.7
for gel cells.<!-- ~MESSAGE_AFTER~ -->
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