This past summer I replaced the battery in my 18ft ski boat and went
to a dual battery system with a selector switch. I had probably
shortened the life of my old battey by letting it sit discharged for
too long over the winter.

This year I'm being more carefull. Here are my thoughts on keeping
batteries charged:

Please feel free to add comments or suggestions.

1) Very important: Do not let your batteries get very low or you will
greatly reduce battery life. I have heard that regular batteries will
be affected by letting then sit below 75% charge and deep cycle should
not be left below 50% charged. Keeping them close to fully charged is
best for prolonged life.

2) Be sure wet cell batteries are full using only distilled water. You
can tell the water level is correct when you look into the cell and
the reflection of the water has a "fish eye" look to it and is not a
flat surface. (If you are curious, it is caused by the surface tension
effect when the water level touches to fill level guide)


3) Check the existing charge level

You can do this using a hydrometer. (under $5) The higher the charge
the more dense the liquid and more balls will float. 4 balls floating
= full charge

Question: How reliable are they? I can’t seam to get more that 3
balls to float (75% charge)

You can also measure the charge state using a voltmeter. Let the
battery sit for approx 3 hrs after charging before you take a reading.
You will get an inaccurate, and high, reading if you measure the
voltage at the battery right after charging it.

Question; I've seen different numbers used for full charge: 14V
13.8V 12.9V What is the best voltage to use for fully charged and
where did the number come from?


5) The max rate to charge a battery is 20% of it’s amp-Hour rating.
Example a 100 amp –hour rated battery should be charged at 20 amps
max. Some chargers automatically adjust the current and length of
charge according to the battery's state of charge and then shut off
when the battery is fully charged. If the charger requires manual
adjustment for current or shut-off, check the charger's instructions
to determine the proper current and length of charge based on your
battery's rating.

6) An automatic charger that reduces current as the battery becomes
charged is best and will give the fastest charging without damaging
the battery.

7) Do not leave a battey connected for over 24 hours to a charger that
does not automaticly shutoff even if it is a "trickle" charger. Some
trickle chargers will raise the voltage as the current drops to levels
that can damage a battery if left for extended periods.




Sources:

Charging Batteries

http://www.ibsa.com/www/faqs/tech_ta...e/charging.htm

Battery Tender

http://batterytender.com/

Kip

On Jan 1, 9:03*pm, kipmc4 wrote:
This past summer I replaced the battery in my 18ft ski boat and went
to a dual battery system with a selector switch. I had probably
shortened the life of my old battey by letting it sit discharged for
too long over the winter.

This year I'm being more carefull. Here are my thoughts on keeping
batteries charged:

Please feel free to add comments or suggestions.

1) Very important: Do not let your batteries get very low or you will
greatly reduce battery life. I have heard that regular batteries will
be affected by letting then sit below 75% charge and deep cycle should
not be left below 50% charged. Keeping them close to fully charged is
best for prolonged life.

2) Be sure wet cell batteries are full using only distilled water. You
can tell the water level is correct when you look into the cell and
the reflection of the water has a "fish eye" look to it and is not a
flat surface. (If you are curious, it is caused by the surface tension
effect when the water level touches to fill level guide)

3) Check the existing charge level

You can do this using a hydrometer. (under $5) The higher the charge
the more dense the liquid and more balls will float. 4 balls floating
= full charge

* Question: How reliable are they? I can’t seam to get more that 3
balls to float (75% charge)

You can also measure the charge state using a voltmeter. Let the
battery sit for approx 3 hrs after charging before you take a reading.
You will get an inaccurate, and high, reading if you measure the
voltage at the battery right after charging it.

Question; I've seen different numbers used for full charge: 14V
13.8V *12.9V *What is the best voltage to use for fully charged and
where did the number come from?

5) The max rate to charge a battery is 20% of it’s amp-Hour rating.
Example a 100 amp –hour rated battery should be charged at 20 amps
max. *Some chargers automatically adjust the current and length of
charge according to the battery's state of charge and then shut off
when the battery is fully charged. If the charger requires manual
adjustment for current or shut-off, check the charger's instructions
to determine the proper current and length of charge based on your
battery's rating.

6) An automatic charger that reduces current as the battery becomes
charged is best and will give the fastest charging without damaging
the battery.

7) Do not leave a battey connected for over 24 hours to a charger that
does not automaticly shutoff even if it is a "trickle" charger. Some
trickle chargers will raise the voltage as the current drops to levels
that can damage a battery if left for extended periods.

Sources:

Charging Batteries

* * * *http://www.ibsa.com/www/faqs/tech_ta...e/charging.htm

Battery Tender

http://batterytender.com/

Kip

Do NOT store ANY battery on cement. It has a bad effect on them. A
piece of plywood works ok to store them on.

wrote in message
...


Do NOT store ANY battery on cement. It has a bad effect on them. A
piece of plywood works ok to store them on.

----------------------------------------------------

(this should be fun)

What, pray tell, is the "bad effect"?

Eisboch

wrote:
On Fri, 2 Jan 2009 08:44:28 -0800 (PST), wrote:

On Jan 1, 9:03 pm, kipmc4 wrote:
This past summer I replaced the battery in my 18ft ski boat and went
to a dual battery system with a selector switch. I had probably
shortened the life of my old battey by letting it sit discharged for
too long over the winter.

This year I'm being more carefull. Here are my thoughts on keeping
batteries charged:

Please feel free to add comments or suggestions.

1) Very important: Do not let your batteries get very low or you will
greatly reduce battery life. I have heard that regular batteries will
be affected by letting then sit below 75% charge and deep cycle should
not be left below 50% charged. Keeping them close to fully charged is
best for prolonged life.

2) Be sure wet cell batteries are full using only distilled water. You
can tell the water level is correct when you look into the cell and
the reflection of the water has a "fish eye" look to it and is not a
flat surface. (If you are curious, it is caused by the surface tension
effect when the water level touches to fill level guide)

3) Check the existing charge level

You can do this using a hydrometer. (under $5) The higher the charge
the more dense the liquid and more balls will float. 4 balls floating
= full charge

Question: How reliable are they? I can’t seam to get more that 3
balls to float (75% charge)

You can also measure the charge state using a voltmeter. Let the
battery sit for approx 3 hrs after charging before you take a reading.
You will get an inaccurate, and high, reading if you measure the
voltage at the battery right after charging it.

Question; I've seen different numbers used for full charge: 14V
13.8V 12.9V What is the best voltage to use for fully charged and
where did the number come from?

5) The max rate to charge a battery is 20% of it’s amp-Hour rating.
Example a 100 amp –hour rated battery should be charged at 20 amps
max. Some chargers automatically adjust the current and length of
charge according to the battery's state of charge and then shut off
when the battery is fully charged. If the charger requires manual
adjustment for current or shut-off, check the charger's instructions
to determine the proper current and length of charge based on your
battery's rating.

6) An automatic charger that reduces current as the battery becomes
charged is best and will give the fastest charging without damaging
the battery.

7) Do not leave a battey connected for over 24 hours to a charger that
does not automaticly shutoff even if it is a "trickle" charger. Some
trickle chargers will raise the voltage as the current drops to levels
that can damage a battery if left for extended periods.

Sources:

Charging Batteries

http://www.ibsa.com/www/faqs/tech_ta...e/charging.htm

Battery Tender

http://batterytender.com/

Kip
Do NOT store ANY battery on cement. It has a bad effect on them. A
piece of plywood works ok to store them on.

"Battery on Cement" issue is a Myth

And to the OP - running a deep cycle battery down to 50% is okay to do
providing you PROMPTLY recharge it fully. Allowing any partially
discharged bbatery to remain that way is very bad for them.


I keep my Parker batteries on the lower shelf of my garage workbench in
the winter. Every month, I hook them up to my auto shut-off charger on
its low amp setting and top them up. I got five years out of a pair of
batteries on the first Yo Ho that way, and they were still good when I
sold that boat.

"Boater" wrote in message
...


I keep my Parker batteries on the lower shelf of my garage workbench in
the winter. Every month, I hook them up to my auto shut-off charger on its
low amp setting and top them up. I got five years out of a pair of
batteries on the first Yo Ho that way, and they were still good when I
sold that boat.


I don't think I'd consider 5 year old batteries in a boat to be in good
shape regardless of how
well they were cared for. Don't like surprises.

Eisboch

"Eisboch" wrote in message
...

"Boater" wrote in message
...


I keep my Parker batteries on the lower shelf of my garage workbench in
the winter. Every month, I hook them up to my auto shut-off charger on
its low amp setting and top them up. I got five years out of a pair of
batteries on the first Yo Ho that way, and they were still good when I
sold that boat.


I don't think I'd consider 5 year old batteries in a boat to be in good
shape regardless of how
well they were cared for. Don't like surprises.

Eisboch

Agree completely. Wife's car was slow starting. Was going to get the
battery tested and when I looked at the battery was 6 years old. Surprized
me that it lasted that long. Got a replacement battery and engine starts
easy now.

"Calif Bill" wrote in message
...

"Eisboch" wrote in message
...

"Boater" wrote in message
...


I keep my Parker batteries on the lower shelf of my garage workbench in
the winter. Every month, I hook them up to my auto shut-off charger on
its low amp setting and top them up. I got five years out of a pair of
batteries on the first Yo Ho that way, and they were still good when I
sold that boat.


I don't think I'd consider 5 year old batteries in a boat to be in good
shape regardless of how
well they were cared for. Don't like surprises.

Eisboch

Agree completely. Wife's car was slow starting. Was going to get the
battery tested and when I looked at the battery was 6 years old.
Surprized me that it lasted that long. Got a replacement battery and
engine starts easy now.

My vehicle batteries usually last 5-7 years ... even with our 4 months of
winter

On Jan 2, 2:21*pm, "Calif Bill" wrote:
"Eisboch" wrote in message

...







"Boater" wrote in message
...

I keep my Parker batteries on the lower shelf of my garage workbench in
the winter. Every month, I hook them up to my auto shut-off charger on
its low amp setting and top them up. I got five years out of a pair of
batteries on the first Yo Ho that way, and they were still good when I
sold that boat.

I don't think I'd consider 5 year old batteries in a boat to be in good
shape regardless of how
well they were cared for. *Don't like surprises.

Eisboch

Agree completely. *Wife's car was slow starting. *Was going to get the
battery tested and when *I looked at the battery was 6 years old. *Surprized
me that it lasted that long. *Got a replacement battery and engine starts
easy now.- Hide quoted text -

- Show quoted text -

I don't know what has changed, but used to be, a battery would slowly
go bad. My recent experiences were that the battery would go bad all
of a sudden. Three times, two in my Jeep, and one in my boat. Jeep
started perfect, drove to the office, went to leave, and nothing.
Interior light wouldn't even come on. Happened a few years later, same
vehicle. Boat battery, went out, battery dead. Charged overnight,
still dead.

On Fri, 2 Jan 2009 11:21:30 -0800, "Calif Bill"
wrote:


"Eisboch" wrote in message
m...

"Boater" wrote in message
...


I keep my Parker batteries on the lower shelf of my garage workbench in
the winter. Every month, I hook them up to my auto shut-off charger on
its low amp setting and top them up. I got five years out of a pair of
batteries on the first Yo Ho that way, and they were still good when I
sold that boat.


I don't think I'd consider 5 year old batteries in a boat to be in good
shape regardless of how
well they were cared for. Don't like surprises.

Eisboch

Agree completely. Wife's car was slow starting. Was going to get the
battery tested and when I looked at the battery was 6 years old. Surprized
me that it lasted that long. Got a replacement battery and engine starts
easy now.

Too late for that one, but I think wiping my batteries down has made
them last years longer. Do it when I change oil.
You'll notice a thin sheen of acid/oil on the battery top.
Think that's bad due to allowing some current discharge across cells.
But I'm not much on electrics.
Use a clean rag and watch the acid.
Read it many years ago and it seems to do some good.

--Vic

Calif Bill wrote:
"Eisboch" wrote in message
...
"Boater" wrote in message
...

I keep my Parker batteries on the lower shelf of my garage workbench in
the winter. Every month, I hook them up to my auto shut-off charger on
its low amp setting and top them up. I got five years out of a pair of
batteries on the first Yo Ho that way, and they were still good when I
sold that boat.

I don't think I'd consider 5 year old batteries in a boat to be in good
shape regardless of how
well they were cared for. Don't like surprises.

Eisboch

Agree completely. Wife's car was slow starting. Was going to get the
battery tested and when I looked at the battery was 6 years old. Surprized
me that it lasted that long. Got a replacement battery and engine starts
easy now.



If you don't use your boat often, or never go far from the dock, you
really don't need to worry about having a 5 yr old battery. If the
battery fails, you just paddle back to the dock. As Harry stated, in 5
yrs he put on less than 125 hrs on the engine because he would always
fish less than 15 min. from shore.

I automatically replace my auto battery after 5 yrs, and that is used
daily.