I have a cruiser with 3 - 12 volt batteries installed, the boat is twin screw
and has 2 battery switches (1,2,all,off) type, and finally a 30 amp battery
charger with terminals for all 3 batteries.

I always leave the charger on at the dock with shorepower but the past couple
of weeks I have 'cooked' 2 of the 3 batteries (maintenance free, probably 5
years old). Friends on the dock are guessing that the battery charger is
broken. Although it still charges fine, they suspect that it doesn't shut off
when the batteries are fully charged, causing them to boil over and eventually
dry up.

Here's my questions:

I just purchased 3 'dual purpose' Exide brand marine batteries that are not
maintenance free so I can pop the caps and see if there's water in the cells.
Do you think I can continue to use the original battery charger and just watch
to see that they don't boil dry?

A new charger which will charge 3 batteries is around $300. (ouch). I can get
a guest charger (2611) for $100 that is 10 amp on 2 circuits, for 2 batteries.
What will happen if I connect 2 batteries to one of the terminals in the
charger? Will that work or will I break something?

My other thought is to only hook up 2 of the 3 batteries to the new charger and
leave the 3rd one to charge when the engine is running, but not use that 3rd
battery for any accessories. This seems like a logical approach to me.

Any comments?

Thanks.

Wklkj wrote:
I have a cruiser with 3 - 12 volt batteries installed, the boat is twin screw
and has 2 battery switches (1,2,all,off) type, and finally a 30 amp battery
charger with terminals for all 3 batteries.

I always leave the charger on at the dock with shorepower but the past couple
of weeks I have 'cooked' 2 of the 3 batteries (maintenance free, probably 5
years old). Friends on the dock are guessing that the battery charger is
broken. Although it still charges fine, they suspect that it doesn't shut off
when the batteries are fully charged, causing them to boil over and eventually
dry up.

It's always possibly the chargers fault however 5 years isn't too bad
for boat batteries. So just the fact they lasted 5 yrs tends to make the
charger look OK.

Here's my questions:

I just purchased 3 'dual purpose' Exide brand marine batteries that are not
maintenance free so I can pop the caps and see if there's water in the cells.
Do you think I can continue to use the original battery charger and just watch
to see that they don't boil dry?

Yes but even better buy a cheap multimeter & verify what's actually
happening.

These batteries are new so after you've been for a run & they're
charged, let them sit overnight with one lead disconnected (so you rule
out any circuit leaks)

Next morning the multimeter should read around 12.6 volts when you put
the multimeter on each battery i.e. fully charged.

Now reconnect them & turn on the charger but don't have anything else
turned on. Leave the charger on for at lease a few hours again overnight
would be good.

To not risk wrecking your new little multimeter you could use a proper
auto accessory amp meter, but given the elcheapo multimeters are under
$10 these days & go to 10 amps anyway, take the risk:-) Following the
multimeter's instruction sheet, put it in series with each of the
batteries in turn (charger still on), set to read "amps". If the charger
is behaving it should have cut the charge rate back to 1 or 2 amps on
new fully charged batteries. If that's what it reads then all seems
well. Yes check the water regularly to be safe as you should anyway &
your old batteries died because they were ...um.......old.


A new charger which will charge 3 batteries is around $300. (ouch). I can get
a guest charger (2611) for $100 that is 10 amp on 2 circuits, for 2 batteries.
What will happen if I connect 2 batteries to one of the terminals in the
charger? Will that work or will I break something?

No you won't "break" anything but a 10 amp charger will not put out 10
amps for any time & will most likely be continuous rated at max output
more like 6 amps. I will charge 2 batteries (so long as the third is
totally isolated from the circuit) but it will take a while if they're
flat to begin. It would be OK as a way of "maintaining" well charged
batteries when the boat isn't used.

My other thought is to only hook up 2 of the 3 batteries to the new charger and
leave the 3rd one to charge when the engine is running, but not use that 3rd
battery for any accessories. This seems like a logical approach to me.

It is and you should always try to have the "start" battery protected
from discharge should someone (never you of course:-)) leave something
on, or a bad cell in any battery will milk the others in that circuit so
all are flat.


K


Any comments?

Thanks.

On 11 Sep 2004 04:37:36 GMT, (Wklkj) wrote:

I have a cruiser with 3 - 12 volt batteries installed, the boat is twin screw
and has 2 battery switches (1,2,all,off) type, and finally a 30 amp battery
charger with terminals for all 3 batteries.

I always leave the charger on at the dock with shorepower but the past couple
of weeks I have 'cooked' 2 of the 3 batteries (maintenance free, probably 5
years old). Friends on the dock are guessing that the battery charger is
broken. Although it still charges fine, they suspect that it doesn't shut off
when the batteries are fully charged, causing them to boil over and eventually
dry up.

At five years and constant charging, that was probably as far as they
were going to go anyway.

Here's my questions:

I just purchased 3 'dual purpose' Exide brand marine batteries that are not
maintenance free so I can pop the caps and see if there's water in the cells.
Do you think I can continue to use the original battery charger and just watch
to see that they don't boil dry?

A new charger which will charge 3 batteries is around $300. (ouch). I can get
a guest charger (2611) for $100 that is 10 amp on 2 circuits, for 2 batteries.
What will happen if I connect 2 batteries to one of the terminals in the
charger? Will that work or will I break something?

Karen has this one exactly right. Get a cheapo multimeter - you can
get them ad job lot stores under the Cal Hawk label for $3 - $4. Just
wire it across a battery that has been under load for a while and
measure the amperage drop when charging.. If it stays at 10 amps (or
what ever amps) and doesn't drop, it's junk and you need a new one.
If it does drop, monitor it until it gets to 1 to 2 amps. If it's a
switched charger, it will actually shut off until the voltage monitor
flips it on, but I don't think that's the case here.

It's not a good idea to use one charge circuit for two batteries.

Take care.

Tom

"The beatings will stop when morale improves."
E. Teach, 1717

5 year old batteries, you done well!

"Wklkj" wrote in message
...
I have a cruiser with 3 - 12 volt batteries installed, the boat is twin
screw
and has 2 battery switches (1,2,all,off) type, and finally a 30 amp
battery
charger with terminals for all 3 batteries.

I always leave the charger on at the dock with shorepower but the past
couple
of weeks I have 'cooked' 2 of the 3 batteries (maintenance free, probably
5
years old). Friends on the dock are guessing that the battery charger is
broken. Although it still charges fine, they suspect that it doesn't shut
off
when the batteries are fully charged, causing them to boil over and
eventually
dry up.

Here's my questions:

I just purchased 3 'dual purpose' Exide brand marine batteries that are
not
maintenance free so I can pop the caps and see if there's water in the
cells.
Do you think I can continue to use the original battery charger and just
watch
to see that they don't boil dry?

A new charger which will charge 3 batteries is around $300. (ouch). I
can get
a guest charger (2611) for $100 that is 10 amp on 2 circuits, for 2
batteries.
What will happen if I connect 2 batteries to one of the terminals in the
charger? Will that work or will I break something?

My other thought is to only hook up 2 of the 3 batteries to the new
charger and
leave the 3rd one to charge when the engine is running, but not use that
3rd
battery for any accessories. This seems like a logical approach to me.

Any comments?

Thanks.

Battery charging occurs at 13.8 to 14.1 volts give or take and is battery
type dependent. If your charger holds that voltage even though the amps
drop to minimal it will boil the water from the batteries. The new chargers
of today will drop the voltage back to 12.9 (or so) when the amps drop off
for "float".

I had an old West Marine charger (no "float") years ago that liked to cook
batteries. I had to add water monthly. I installed a timer on the plug
that cycled the charger on for about 1 hour per day. This solved the
problem but a better charger was the real trick. I highly recommend one
with "bulk", "Accept", and "float" capabilities.

Five years on a set of batteries is good. I am kind of jealous.

"Woodchuck" wrote in message
...
5 year old batteries, you done well!

"Wklkj" wrote in message
...
I have a cruiser with 3 - 12 volt batteries installed, the boat is twin
screw
and has 2 battery switches (1,2,all,off) type, and finally a 30 amp
battery
charger with terminals for all 3 batteries.

I always leave the charger on at the dock with shorepower but the past
couple
of weeks I have 'cooked' 2 of the 3 batteries (maintenance free, probably
5
years old). Friends on the dock are guessing that the battery charger is
broken. Although it still charges fine, they suspect that it doesn't
shut
off
when the batteries are fully charged, causing them to boil over and
eventually
dry up.

Here's my questions:

I just purchased 3 'dual purpose' Exide brand marine batteries that are
not
maintenance free so I can pop the caps and see if there's water in the
cells.
Do you think I can continue to use the original battery charger and just
watch
to see that they don't boil dry?

A new charger which will charge 3 batteries is around $300. (ouch). I
can get
a guest charger (2611) for $100 that is 10 amp on 2 circuits, for 2
batteries.
What will happen if I connect 2 batteries to one of the terminals in the
charger? Will that work or will I break something?

My other thought is to only hook up 2 of the 3 batteries to the new
charger and
leave the 3rd one to charge when the engine is running, but not use that
3rd
battery for any accessories. This seems like a logical approach to me.

Any comments?

Thanks.