TWL: did I goof by leaving my battery charger on for one year
Kenny,
Depends on your charger and your batteries, but if your boat is still floating,
you're probably fine. And if your batteries and charger are happily matched,
keeping your batteries topped up for the year means that they're in tip-top shape.
Of course, if they're mismatched (trickle-charger at 14.5 volts and sealed gels, for
example), then your batteries are probably toast, and you'll have to fork over for a
new set.
For fire prevention and electrolysis control, it's best to unplug shore power and
turn off all your battery isolation switches. Most of us, though, turn off the
isolators, but leave the shore power connected and the battery charger charging.
Those of us, that is, who don't live aboard (which used to be us, but then we moved
on board and the charger runs all the time now). Again, if you're not overcharging,
then you can't pick a better way to keep your batteries living long.
Our sailboat had a lead-acid starting battery that was lightly used and plugged into
a battery charger for all its life. It went on the boat in 1993, and we didn't
replace it when we bought the boat in 1999. We just sold that boat, and told the
new owner that he might have to replace the starting battery one day soon, but we
didn't have the heart to get rid of it because it still worked great.
As with all things related to boating, the answer's never black and white.
Doug Hoople
M/V Bomar
1963 Stephens Bros. 50 FDMY
Sausalito, CA
Actually, Kenny,
Just so you know, the single most guaranteed way to kill your batteries is to let
them go flat and then leave them flat. Happens all the time to boats that sit on
brokerage docks for more than a month or two.
Doug Hoople
M/V Bomar
1963 Stephens Bros. 50 FDMY
Sausalito, CA
If they're sealed batteries (and they're probably not), don't equalize the batteries.
They'll gas irreversibly.
Of course, if they're sealed and if you try to follow Arild's procedure you won't get
to the equlization
step, because you won't be able to measure Specific Gravity in the first place. :-)
Doug Hoople
Arild wrote:
To test the batteries for actual capacity, first measure the S.G. of each cell.
Test before adding any electrolyte. If the cells do not read the same,add
electrolyte
as necessary and then do an equalize cycle for an hour or two.
Folks;
I just read in the manual that I should shut the battery charger off when I
leave the boat. (it actually says I should turn the batteries
off................)
Now Im confused. Should I turn the batteries off or turn the charger off, or
both?
Have I harmed the batteries this past year and one half by leaving the
charger and the batteries on low the whole time
There have been weeks gone by when I have not really used the boat other than
stay on it occassionally, so I have not run the batteries down much at all.
The batteries have 11/98 on them, so I assume they are 3 1/2 years old
Im feeling real dumb right now
Kenny
<A HREF="http://hometown.aol.com/ksprice/myhomepage/photo.html">grandfinale</A>
Kenny's question is relevant to many people.
Have I harmed the batteries this past year and one half by leaving the
charger and the batteries on low the whole time.
REPLY
Doug's reply reflects conventional wisdom. In most cases you will find the
batteries are fine.
To test the batteries for actual capacity, first measure the S.G. of each cell.
Test before adding any electrolyte.
If the cells do not read the same,add electrolyte as necessary and then do an
equalize cycle for an hour or two. Let the battery sit for an hour to cool off
and stabilize. then measure the S.G again. A good battery will now read
equally on all cells and it should read 1.265 corrected for temperature.
To get an idea of actual storage capacity do a load test. Here is where an
inverter is real handy. A 100 watt bulb will draw 10 amps on the 12V side and
a 200 lamp will draw 20 amps on the DC side. Plug an electric clock - the
kind with a motor movement not a digital read-out- into the inverter to measure
elapsed time until the safety limit of 10.5 cuts off the inverter.
If you start with 12:00 then the clock will read out the elapsed time the battery
supplied 10 or 20 amps. multiply one by the other to get amp hours.
Remember that a 200 amp hour battery bank will only deliver 100 amp hours
before it is exhausted and this is usually measured at the 20 amp rate.
If your battery has less than 80% capacity but the S.G. readings were good,
chances are you have sulfated batteries. This can occur even if the battery is
floated at 13.2V on a good charger.
Good luck
Arild
After reading the glowing reports from Arild, I
installed a Pulsetech Powerpulse 12 "battery
maintenance system" (www.pulsetech.net) from a NAPA
auto parts store for $73. After a couple of weeks, I
notice a dramatic improvement in the charging and
discharging capabilities of the house bank of 6 golf
cart batteries, even though they are only 4 months
old.
Because my 12v refrigerator controller doesn't like to
work at under 12.0v at it's terminals, I do not
discharge my house bank to below 12.2v at the battery
terminals. With this limit, I was only able to get
about 150 AH before needing to recharge. Now I get
about 300 AH from my 660 AH bank before reaching the
12.2v limit and recharging.
Although Pulsetech recommends a Powerpulse 12 for each
of the (3) pairs of parallel wired golfcarts, I have
found that the one unit works well. I may move its
attachment points among the (3) battery pairs each
month or so, when I am in the neighborhood to top up
water. Just a happy customer.
Mark Richter, Winnie the Pooh, 46' custom troller
presently in Sarasota, headed to St. Pete, Mobile,
Chatanooga, and Knoxville.
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