Outboard Overcharging... (long)
 

This problem comes up over and over again in the newsgroups and boating boards
and NO ONE has answered it...

A lot of older outboards came with un-regulated charging systems and I have
one.
I read about people reporting that their voltage had risen to 16+ volts. Last
year after over TEN years of correct voltage I bought a new battery and mine
started doing the same thing. I verified this with the boats volt meter gauge,
a Fluke digital VOM and a Simpson 260 analog VOM. There is 16 volts there.
Everything in the charging system is within specs. I have even replaced a lot
of the system and its still 16+ volts. After not getting an answer from anyone
(including the manufacturer) as to what can cause this I just let it go to see
what would happen. Its been running 2 seasons like this so far and nothing bad
or what should be expected has happened.

1. Nothing has burned out or been hurt. (Fish finder, lights, guages, GPS)
2. It has not caused the battery to boil off water, I have not added one drop.
The battery is FINE.

Some people have reported that turning on accesories will drop the voltage and
this is correct. It worked on mine for a while but it will eventually charge
the battery and runs around 15 volts. Leaving the lights on for a while to
discharge the battery will do the same thing. Its amazing how this 5 amp
system can charge so fast.

After many trys I finally got to actually speak with an engineer at the
manufacturer. He told me they were always aware of this high voltage and their
guages (OMC) were specifically designed to handle the higher voltages without
harm. I asked him why they would even make a system that could even produce 16
volts in the first place and he said "it could do 45 volts". WHAT!!!!!!

I asked why they were not concerned about the battery gassing and causing an
explosion. His reply was that their un-regulated charging systems produce a
very low amperage. Mine is around 5 amps. He said in a simple un-regulated
charging system there is a stator (generates AC) and a rectifier (changes AC to
DC) and the battery acts as the regulator. He could not tell me why mine has
run all these years at 13.5 - 14.5 volts and suddenly started running at 16.

He did give me these tips for ANYONE with an un-regulated charging system:

1. NEVER use a maintenance free battery.
2. NEVER use any of the new AGM batteries.
3. NEVER use one of the new spiral wound batteries.
3. ONLY use a battery with caps so you can check the water level on a regular
basis.

FINE.
I saw this motor run at the correct voltage for years and I refuse to just let
it keep doing this because it can. Being somewhat of an electrician I need a
reason.
I checked every wire and ground in the boat, they were fine. A loose ground
could cause a rise in voltage. I tested every plug and ground on the motor. I
disconnected everything from the boat except for the motor to eliminate wiring
problems and it STILL runs at 16 volts. I threw some money at it and bought a
new rectifier which didnt help.

Now I am down to the battery. The factory manual calls for a battery with "a
minimum of 360 CCA". I bought a battery with 1000 CCA and it went to 16 volts
instantly. I borrowed a battery with 600 CCA and got 16 volts after it charged
up. I bought another small battery with 420 CCA and have not had the chance to
test it yet. If this does not work I am going to try a battery combiner and
let it charge my deep cycle trolling battery too. If I give it a load, its
fine (about 14 volts). I could rig some kind of regulator to it but it never
had one before and shouldnt need it now.
On an interesting note a weak battery will let it run within normal voltage
range because it will never charge up fully. Problem with that is you cant buy
a weak battery.
I will test the new small battery (420 CCA) to see if that works, it stayed
under 14.5 volts on the muffs at around 1000 rpm's for about 10 minutes which
is a record. :) Since the smaller battery will discharge more during starting
it might give the charging system something to do but being smaller it might
charge up faster.... hmm.

If anyone out there has any logical suggestions I will try them and I would
like to hear from you. There has to be an answer to this. Could something
cause three VOM's to read incorrectly?

Outboard Overcharging... (long)
 

Also Sprach CCred68046 :

A simple answer to a long problem: Buy a solid state rectifier/regulator
intended for an old motorcycle. I bought one made by Tympanium and sold
as a replacement for Triumph motorcycles. Just be careful with polarity,
the old Triumph's had a positive ground electrical system. Make sure that
you connect the negative output to ground, even though the instuctions say
positive.

I bought mine locally, there's a great bike shop near me, but here's an
online retailer: http://www.oldbritts.com/17_01233.html

Dan

--
Give a hungry man a fish and you have fed him for a day, but give him a case
of dynamite and soon the entire village will be showered with mud and water
and hard-to-identify little chunks of fish.

Outboard Overcharging... (long)
 

A simple answer to a long problem: Buy a solid state rectifier/regulator
intended for an old motorcycle.

Thanks Dan,
As I stated in the first thread I know I could do that. I know I could get a
regulator kit from OMC or West Marine to do this too.
BUT....
I really want to know how this thing is defying physics and everything I was
ever taught about electricity.
It should be ruining stuff like the battery and electronics and its not. I can
afford the regulator easy but I want to know...
Why did it work perfectly for so many years and just change? If this were not
such a simple system I would buy the regulator and forget it.
I cant find ONE article doing a google search where someone has found out why
or how these old outboards are doing this.
16 volts should be frying stuff, even at 5 amps.
By the way, just curious again... what motor did you put that regulator on?
If anyone else has an outboard doing this I would like to know the brand and
horsepower.

Thanks!!

Outboard Overcharging... (long)
 

I had the same experience with my 1989 vintage merc/mariner 75. It started with
a new battery. All I could think was that they changed the way they make
batteries. I did notice lights didn't last as long after that and batteries
seemed to "boil off" a little faster but everything else was OK.

Outboard Overcharging... (long)
 

On 09 Jun 2004 14:05:58 GMT, obull (CCred68046)
wrote:

Why did it work perfectly for so many years and just change?

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

The new battery is probably better at accumulating a surface charge
for some reason. It reaches full charge and keeps on going until it
reaches an equilibrium with the 5 amps or so that the alternator is
supplying. The older battery may have had a lower internal
resistance, different type of plates, more leakage, more capacity,
etc. Battery life will definitely be shortened under this scenario
and you may experience premature failure of voltage sensitive
equipment.

Outboard Overcharging... (long)
 

I had the same experience with my 1989 vintage merc/mariner 75. It started
with a new battery.
All I could think was that they changed the way they make
batteries.

That is exactly how mine did it. New battery and all the trouble started.
Every time I put the old battery back in it was fine but finally it just died
from old age. It lasted 4 years.

I had that same thought as you but from what I can see, refillable flooded cell
batteries are no different. Outside of adding some LED lighting, nothing on my
boat changed but the battery. I thought the LED's could have been suspect but
I took everything out of the system but the motor and it didnt change.
It almost has to be something with the battery. Right now I'm trying to find
out from an expert if a bigger CCA battery or a smaller CCA battery could make
a difference since it is the regulator in the system.

Thanks for the info.

Outboard Overcharging... (long)
 

Battery life will definitely be shortened under this scenario
and you may experience premature failure of voltage sensitive
equipment.

Exactly my point.
Based on everything I was taught, you should be right and that is exactly whats
NOT happening. NONE of those things have happened in two (almost 3) years now.
I intentionally let it go hoping something would burn up or die thinking I
could then solve this. I have not had anything burn out nor have I added any
water to the battery!

Outboard Overcharging... (long)
 

On 09 Jun 2004 15:29:40 GMT, obull (CCred68046)
wrote:

I have not had anything burn out nor have I added any
water to the battery!

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

Part of that could be luck with the electronics. The water not
boiling off can be explained by the low charging current and the
battery's apparent ability to develop a high surface charge.
Different battery, different results.

Outboard Overcharging... (long)
 

Part of that could be luck with the electronics. The water not
boiling off can be explained by the low charging current and the
battery's apparent ability to develop a high surface charge.
Different battery, different results.


Ok Wayne,
That makes sense but I have tried 4 different batteries so far. You would
think that I would have at least burn out a light bulb or something...
Based on your thoughts would you think that in a system like this a bigger
battery or a smaller battery should work better? Remember, as many others
mentioned, these things ran perfect for years as did mine then just went crazy.
Some of the old posts I found state the problem starts with a new battery.
Do you know of any major differences in regular (not maintenence free)
batteries of the 80's and what they have now?

Outboard Overcharging... (long)
 

On 09 Jun 2004 17:06:30 GMT, obull (CCred68046)
wrote:
Do you know of any major differences in regular (not maintenence free)
batteries of the 80's and what they have now?

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

I'm not aware of specific differences but there are differences
between manufacturers and between battery types, i.e., starting
batteries vs. deep cycle. I'm guessing a little but my sense of it is
that a smaller battery would be more likely to achieve a 100% charge
and float up to the kind of voltage you're seeing. It might be
interesting to connect a good size marine battery like a 4D in
parallel and see what hapens to the voltage. My guess is that it
would drop as the larger battery should be more capable of absorbing
charge.

Outboard Overcharging... (long)
 

I'm not aware of specific differences but there are differences
between manufacturers and between battery types, i.e., starting
batteries vs. deep cycle. I'm guessing a little but my sense of it is
that a smaller battery would be more likely to achieve a 100% charge
and float up to the kind of voltage you're seeing. It might be
interesting to connect a good size marine battery like a 4D in
parallel and see what hapens to the voltage. My guess is that it
would drop as the larger battery should be more capable of absorbing
charge.

I was thinking along the same lines too and bought a 1000 CCA battery. The
motor specs call for a minimum of 360 CCA. So far it has done the opposite of
what I thought would happen.
Someone in the electricial engineering group suggested that I may have been
wrong buying a larger battery because its not discharging from the low starter
demand (the motor runs perfect and usually starts instantly). and the bigger
battery has more resistance.

Outboard Overcharging... (long)
 

"CCred68046" wrote in message
...




If this does not work I am going to try a battery combiner and
let it charge my deep cycle trolling battery too.

that sounds like the easiest and best approach!

If the outboard can only drive 5 amps it shouldn't take much of a battery
bank to provide that kind of load. If you have the current to spare, there
is no reason not to charge the trolling battery.

I suspect that the higher voltage is because the new battery is fully
charged, where your previous battery was always at some level of discharge.
An experiment you might want to try would be to drain the battery a bit and
then hook it up. Hook it up to your trolling motor for about 20 minutes and
then swap back.


Rod

Outboard Overcharging... (long)
 

On 09 Jun 2004 05:08:44 GMT, obull (CCred68046)
wrote:

This problem comes up over and over again in the newsgroups and boating boards
and NO ONE has answered it...

A lot of older outboards came with un-regulated charging systems and I have
one.
I read about people reporting that their voltage had risen to 16+ volts. Last

snip

o be an answer to this. Could something
cause three VOM's to read incorrectly?


You kind of helped me answer a question I had not asked. Thanks. I
recently bought two 6 volt solar cells from Walmart and wired them in
series to charge my battery on my little boat. Since my motor does not
have any hookups to charge the battery I had to think of something.
Nothing sucks worse than being out fishing at night and having your
lights go out. Since I only use my boat for a few hours each week the
sun has plenty of time to recharge from what little use I give it.

But what had me worried was that in bright sunlight the cells were
putting out a combined 16 volts. I thought that might fry my fish
finder and although it is a cheap one, I can't afford to replace it.
Since reading the replies to your post I feel more assured that 200
milliamps at 16 volts from a couple solar cells are not a serious
threat to a fish finder. If your equipment can handle 16 volts at 5
amps I should be in the clear. Or am I wrong?

Outboard Overcharging... (long)
 

On Thu, 10 Jun 2004 23:53:12 GMT, Ookie Wonderslug
wrote:
Since reading the replies to your post I feel more assured that 200
milliamps at 16 volts from a couple solar cells are not a serious
threat to a fish finder. If your equipment can handle 16 volts at 5
amps I should be in the clear. Or am I wrong?

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

You should be fine, 200 milliamps is not enough to damage the battery.

Outboard Overcharging... (long)
 

If your equipment can handle 16 volts at 5
amps I should be in the clear. Or am I wrong?

Mine has been going like this for almost 3 years now. Based on my experience
you will be OK.

Outboard Overcharging... (long)
 

Clamp it with a Zener Diode somewhere on the 12v output line. All excess
current will bleed off.

-W

Outboard Overcharging... (long)
 

Clamp it with a Zener Diode somewhere on the 12v output line. All excess
current will bleed off.

Thanks Clams,

I know I could regulate it easily. You are an old Merc fan and you know how to
fix it so you must have run into this before. What I am looking for is the
reason its doing this now after it ran fine all those years. Everything is
still in spec electrically. I really find this interesting. All the posts on
the web about it and no one can or has answered it yet.

Outboard Overcharging... (long)
 

"CCred68046" wrote in message
...
Clamp it with a Zener Diode somewhere on the 12v output line. All excess
current will bleed off.

Thanks Clams,

I know I could regulate it easily. You are an old Merc fan and you know
how to
fix it so you must have run into this before. What I am looking for is
the
reason its doing this now after it ran fine all those years. Everything
is
still in spec electrically. I really find this interesting. All the posts
on
the web about it and no one can or has answered it yet.


The biggest reason that voltage climbs so high on an unregulated system is
that the battery is too small a capacity, and/or is a sealed or "maintenance
free" version. You want a "flooded cell" battery, the largest you can fit
and afford, to run your boat's electrics. Get a group 27 heavy duty battery
and you won't have any problems. A cheaper way of regulating the charging
system is just to use an additional battery in parallel to absorb the extra
charging.

Years back we told customers to run the boat lights all the time and have
the dash lights wired into the key switch so they were always on. That also
cut down on the condensation inside the gauge faces.

Bill Grannis
service manager

Outboard Overcharging... (long)
 

"Ookie Wonderslug" wrote in message
...
But what had me worried was that in bright sunlight the cells were
putting out a combined 16 volts. I thought that might fry my fish
finder and although it is a cheap one, I can't afford to replace it.
Since reading the replies to your post I feel more assured that 200
milliamps at 16 volts from a couple solar cells are not a serious
threat to a fish finder. If your equipment can handle 16 volts at 5
amps I should be in the clear. Or am I wrong?


It's extremely unlikely that the solar cells will be putting out 16v with
any kind of load on them. I'm betting that you measured 16v with no load
(open circuit). You'll be fine.

Jack

Outboard Overcharging... (long)
 

The biggest reason that voltage climbs so high on an unregulated system is
that the battery is too small a capacity, and/or is a sealed or "maintenance
free" version. You want a "flooded cell" battery, the largest you can fit
and afford, to run your boat's electrics. Get a group 27 heavy duty battery
and you won't have any problems. A cheaper way of regulating the charging
system is just to use an additional battery in parallel to absorb the extra
charging.

Hey, good to see your still in the group Bill!
I have tried several batteries... I'm currently running a group 27 1000cca. I
have tried 3 BIG non maintenance free batteries. Everyone of them did the
same thing. The factory service manual calls for a minimun of 360 CCA. It
seems like Im not running them down enough to give the charging system
something to do. I just bought a 420 CCA to try that because a few of the guys
in the electricial engineering group said the bigger battery has MORE
resistance to charging once its full and is adding to the problem.
I gave up on electrical "experts", they cant agree on this at all. I'll trust
your experience on this. Money is not the problem. If you know of a specific
brand and model of battery that will work I will try one.
Now for a good laugh... I just happened to see another motor like mine Saturday
at the dock and talked with the owner... Now get this.. this guy didnt have a
clue about his old boat but he let me look at it. The thing is running a
perfect 14.5 volts and he's running a 520 CCA MAINTENANCE FREE battery.
ARRRRRRG.

Outboard Overcharging... (long)
 

Run into this? My boat is named *after* that very problem! And there ar
emany on this very board that watched me tear my hair out.

My 1962 Merc 1000 (advertised in '62 as the Black Phantom) had this problem,
which would cause the voltage to rise and then the condensors (at the
breaker points) to fail at about 17 volts. This of course, after about 10
minutes at WOT after the start-up. It took me a while to figure out *why*
the motor would always turn to crap after about 10 minutes runtime.
Overvoltage was the *last* thing that came to mind, I was looking for a
thermal intermittant in the ignition.

The problem itself, that motor, and (by default) that boat, *earned* the
name of "The Phantom Menace", as it would always quit once you were far
from shore.

I don't totally get the mechanics of the problem, just that the newer
batteries don't seem to be able to bleed off the excess output like the old
ones did. On my new boat (the PMII) I installed a later model rectifier /
regulator combo on my big Inline.

-W

(now you know why Mercury paint is called "Phantom Black" by the way)





"CCred68046" wrote in message
...
Clamp it with a Zener Diode somewhere on the 12v output line. All excess
current will bleed off.

Thanks Clams,

I know I could regulate it easily. You are an old Merc fan and you know
how to
fix it so you must have run into this before. What I am looking for is
the
reason its doing this now after it ran fine all those years. Everything
is
still in spec electrically. I really find this interesting. All the posts
on
the web about it and no one can or has answered it yet.

Outboard Overcharging... (long)
 

Try this question in rec.crafts.metalworking
Someone there might have the answer.

"CCred68046" wrote in message
...
This problem comes up over and over again in the newsgroups and boating
boards
and NO ONE has answered it...

A lot of older outboards came with un-regulated charging systems and I
have
one.
I read about people reporting that their voltage had risen to 16+ volts.
Last
year after over TEN years of correct voltage I bought a new battery and
mine
started doing the same thing. I verified this with the boats volt meter
gauge,
a Fluke digital VOM and a Simpson 260 analog VOM. There is 16 volts there.
Everything in the charging system is within specs. I have even replaced a
lot
of the system and its still 16+ volts. After not getting an answer from
anyone
(including the manufacturer) as to what can cause this I just let it go to
see
what would happen. Its been running 2 seasons like this so far and nothing
bad
or what should be expected has happened.

1. Nothing has burned out or been hurt. (Fish finder, lights, guages,
GPS)
2. It has not caused the battery to boil off water, I have not added one
drop.
The battery is FINE.

Some people have reported that turning on accesories will drop the voltage
and
this is correct. It worked on mine for a while but it will eventually
charge
the battery and runs around 15 volts. Leaving the lights on for a while
to
discharge the battery will do the same thing. Its amazing how this 5 amp
system can charge so fast.

After many trys I finally got to actually speak with an engineer at the
manufacturer. He told me they were always aware of this high voltage and
their
guages (OMC) were specifically designed to handle the higher voltages
without
harm. I asked him why they would even make a system that could even
produce 16
volts in the first place and he said "it could do 45 volts". WHAT!!!!!!

I asked why they were not concerned about the battery gassing and causing
an
explosion. His reply was that their un-regulated charging systems produce
a
very low amperage. Mine is around 5 amps. He said in a simple
un-regulated
charging system there is a stator (generates AC) and a rectifier (changes
AC to
DC) and the battery acts as the regulator. He could not tell me why mine
has
run all these years at 13.5 - 14.5 volts and suddenly started running at
16.

He did give me these tips for ANYONE with an un-regulated charging system:

1. NEVER use a maintenance free battery.
2. NEVER use any of the new AGM batteries.
3. NEVER use one of the new spiral wound batteries.
3. ONLY use a battery with caps so you can check the water level on a
regular
basis.

FINE.
I saw this motor run at the correct voltage for years and I refuse to just
let
it keep doing this because it can. Being somewhat of an electrician I
need a
reason.
I checked every wire and ground in the boat, they were fine. A loose
ground
could cause a rise in voltage. I tested every plug and ground on the
motor. I
disconnected everything from the boat except for the motor to eliminate
wiring
problems and it STILL runs at 16 volts. I threw some money at it and
bought a
new rectifier which didnt help.

Now I am down to the battery. The factory manual calls for a battery with
"a
minimum of 360 CCA". I bought a battery with 1000 CCA and it went to 16
volts
instantly. I borrowed a battery with 600 CCA and got 16 volts after it
charged
up. I bought another small battery with 420 CCA and have not had the
chance to
test it yet. If this does not work I am going to try a battery combiner
and
let it charge my deep cycle trolling battery too. If I give it a load,
its
fine (about 14 volts). I could rig some kind of regulator to it but it
never
had one before and shouldnt need it now.
On an interesting note a weak battery will let it run within normal
voltage
range because it will never charge up fully. Problem with that is you
cant buy
a weak battery.
I will test the new small battery (420 CCA) to see if that works, it
stayed
under 14.5 volts on the muffs at around 1000 rpm's for about 10 minutes
which
is a record. :) Since the smaller battery will discharge more during
starting
it might give the charging system something to do but being smaller it
might
charge up faster.... hmm.

If anyone out there has any logical suggestions I will try them and I
would
like to hear from you. There has to be an answer to this. Could
something
cause three VOM's to read incorrectly?

Outboard Overcharging... (long)
 

I've just accepted it as a fact of life.
Seems as batteries got "better" they lost the ability to bleed off excess
current.
I think Bill came closest to what's going on.
Your charging system isn't broken, nor are your voltmeters.
Your old battery was able to "leak" your overproduction, your new one
can't - it's just that simple.
Nothing is "broken".
At least your boat will still run at 16v :)

The only fix (if you can't find a battery that will bleed it off) is to add
a device to regulate the system.

-W




"CCred68046" wrote in message
...
This problem comes up over and over again in the newsgroups and boating
boards
and NO ONE has answered it...

A lot of older outboards came with un-regulated charging systems and I
have
one.
I read about people reporting that their voltage had risen to 16+ volts.
Last
year after over TEN years of correct voltage I bought a new battery and
mine
started doing the same thing. I verified this with the boats volt meter
gauge,
a Fluke digital VOM and a Simpson 260 analog VOM. There is 16 volts
there.
Everything in the charging system is within specs. I have even replaced
a
lot
of the system and its still 16+ volts. After not getting an answer from
anyone
(including the manufacturer) as to what can cause this I just let it go
to
see
what would happen. Its been running 2 seasons like this so far and
nothing
bad
or what should be expected has happened.

1. Nothing has burned out or been hurt. (Fish finder, lights, guages,
GPS)
2. It has not caused the battery to boil off water, I have not added one
drop.
The battery is FINE.

Some people have reported that turning on accesories will drop the
voltage
and
this is correct. It worked on mine for a while but it will eventually
charge
the battery and runs around 15 volts. Leaving the lights on for a while
to
discharge the battery will do the same thing. Its amazing how this 5
amp
system can charge so fast.

After many trys I finally got to actually speak with an engineer at the
manufacturer. He told me they were always aware of this high voltage
and
their
guages (OMC) were specifically designed to handle the higher voltages
without
harm. I asked him why they would even make a system that could even
produce 16
volts in the first place and he said "it could do 45 volts".
WHAT!!!!!!

I asked why they were not concerned about the battery gassing and
causing
an
explosion. His reply was that their un-regulated charging systems
produce
a
very low amperage. Mine is around 5 amps. He said in a simple
un-regulated
charging system there is a stator (generates AC) and a rectifier
(changes
AC to
DC) and the battery acts as the regulator. He could not tell me why
mine
has
run all these years at 13.5 - 14.5 volts and suddenly started running at
16.

He did give me these tips for ANYONE with an un-regulated charging
system:

1. NEVER use a maintenance free battery.
2. NEVER use any of the new AGM batteries.
3. NEVER use one of the new spiral wound batteries.
3. ONLY use a battery with caps so you can check the water level on a
regular
basis.

FINE.
I saw this motor run at the correct voltage for years and I refuse to
just
let
it keep doing this because it can. Being somewhat of an electrician I
need a
reason.
I checked every wire and ground in the boat, they were fine. A loose
ground
could cause a rise in voltage. I tested every plug and ground on the
motor. I
disconnected everything from the boat except for the motor to eliminate
wiring
problems and it STILL runs at 16 volts. I threw some money at it and
bought a
new rectifier which didnt help.

Now I am down to the battery. The factory manual calls for a battery
with
"a
minimum of 360 CCA". I bought a battery with 1000 CCA and it went to 16
volts
instantly. I borrowed a battery with 600 CCA and got 16 volts after it
charged
up. I bought another small battery with 420 CCA and have not had the
chance to
test it yet. If this does not work I am going to try a battery combiner
and
let it charge my deep cycle trolling battery too. If I give it a load,
its
fine (about 14 volts). I could rig some kind of regulator to it but it
never
had one before and shouldnt need it now.
On an interesting note a weak battery will let it run within normal
voltage
range because it will never charge up fully. Problem with that is you
cant buy
a weak battery.
I will test the new small battery (420 CCA) to see if that works, it
stayed
under 14.5 volts on the muffs at around 1000 rpm's for about 10 minutes
which
is a record. :) Since the smaller battery will discharge more during
starting
it might give the charging system something to do but being smaller it
might
charge up faster.... hmm.

If anyone out there has any logical suggestions I will try them and I
would
like to hear from you. There has to be an answer to this. Could
something
cause three VOM's to read incorrectly?

Outboard Overcharging... (long)
 

"CCred68046" wrote in message
...
The biggest reason that voltage climbs so high on an unregulated system
is
that the battery is too small a capacity, and/or is a sealed or
"maintenance
free" version. You want a "flooded cell" battery, the largest you can fit
and afford, to run your boat's electrics.

Hey, good to see your still in the group Bill!
I have tried several batteries... I'm currently running a group 27
1000cca. I
have tried 3 BIG non maintenance free batteries. Everyone of them did
the
same thing.


What make, model, year outboard do you have?

Most modern batteries cram a lot of CCA (cold cranking amps) into the
design, but with a loss of reserve power. You want a battery with high
reserve minutes, above 200, and that will absorb the excess voltage. Imagine
charging a small garden tractor or motorcycle battery at a constant 6 amps,
the voltage would climb and it would boil away after a short time. Now
charge a huge bus or truck battery, like an 8D, and your voltage may not
even rise above 14.

A group 27, 30, or 31 deep cycle battery, as long as it meets your engine's
CCA requirement, works a lot better than a "new high tech, quick start"
battery, on unregulated systems.

Bill Grannis
service manager