Parasitic drain on battery.

[Joe B]

Tim, I've found that when my boat batteries get old and are ready to get rid of, they seem to take a charge quickly, but won't hold it for long and seem to have no storage ability. As I mentioned, your battery may be toast from going dead and need to be load tested.

[JFP in PA]

Originally Posted by Joe B

Tim, I've found that when my boat batteries get old and are ready to get rid of, they seem to take a charge quickly, but won't hold it for long and seem to have no storage ability. As I mentioned, your battery may be toast from going dead and need to be load tested.

What is happening is the internal resistance of the battery is rising due to plate sulphation over time. The higher internal resistance falsely confuses the charger into thinking the battery is fully charged when in fact it is not, and the charger shuts off.

Sulphation is a normal process in all batteries, but can be nearly eliminated by using a quality maintainer that has a de-sulphation step in the charge profile, which significantly reduces the build up, dramatically extending the battery's life, which more than offsets the extra bucks you spent for the better maintainer.

[Pdwight]

Im with you on that, the plates sulphate and film over with time and the ability to hold a charge gets to be less and less with time.....the plates also wrap with high current charges. I had an EE instructor put it in plain terms "Battery charging is like filling a wooden bucket with water,,,,you can fill it quickly with a firehose but you will never get it completely full and you will most likely damage each time you try....fill it with a trickle of water and it will fill to the top and last a lot longer."

I have also heard that if you run one completely down they will never hold a full 100% charge again

[Joe B]

Originally Posted by Pdwight

I have also heard that if you run one completely down they will never hold a full 100% charge again

This.


(10 characters needed...)