Originally Posted by wunderluster
I will keep the West Marine Dual purpose as the starting battery as long as it lasts.
I have a spring 2007 Deka/WM Dual Purpose battery (green WM label) on my bench right now for equalizing. The battery is still going strong, putting out more than "new" CCA capacity, 650 CCA rated and putting out 658 CCA as measured with the Argus 500 analyzer. This was the reading before equalization
which I have not had a chance to perform yet.
It is not unusual for the Deka and many other brands to put out more CCA than rated for when new but at 5 years it is a little out of the ordinary. Specific Gravity was good and cell water
was even across the cells. It also supports a carbon pile load test done to ABYC load test parameters and remains well within voltage range. The customer uses the boat almost every weekend and does a two week cruise
each season. This is not an unusual finding for Deka batts but is somewhat odd to find on a Dual Purpose used incorrectly as a house battery..
Despite this battery being on a boat sailed off a mooring
, incorrectly being used as a house battery, and only being charged by a 35A dumb regulated alternator
the darn thing is still going at 5 years and is doing just fine. The owner does tend to motor
a lot more than he sails
so this may have helped his bank fend off sulfation.
According to the owner over the last five winters, since October 2007, the battery has been left on-board and charged up with a portable charger
in the fall before covering the boat. Based on the current
tests I suspect this customer may get 7 years or more from it, in spite of the "abuse" he's given it in an incorrect application for the battery. Of course it could fail in the spring as with batteries they can sometimes surprise you and all the testing in the world still can't predict outcomes....
This will be the first time this battery has been equalized and I am curious to see how it tests after equalization
. I did print a test certificate at 658 CCA which I will compare the after equalization number to.
Ideally he should have two deep cycle batteries but he refuses to upgrade until he kills this one. Can't say I blame him as the battery is still good and by buying
at WM he paid a lot more than he should have for it, about double..
He is not interested in paying for a capacity discharge test as the bank is just not worth the cost and time involved.