toedtoes wrote:
Well, so far I do not see any AGM battery owner dissatisfied with their choice. :)
OK, here I am - better late than never.
I've got about 15 years experience, starting with a PWC. These little critters like to jump up and down a lot and sometimes flip, so a lead acid battery isn't the best choice. I hate acid in the hull....LOL. I bought an AGM and it worked fine for 2 years. Then I sold the 'ski, so no follow up info for that one. I immediately replaced the new one's acid battery with an AGM. I liked it so much, I replaced the battery in 2 of my other boats, lawn tractor and car all the same year. In retrospect, I should have given more time to gain experience.
The second year the 1 year old ski battery was completely dead, even though I maintained it properly all Winter. The dealer said he had a whole batch of bad ones (a couple dozen other ones came back as well), and it was replaced under warranty.
After about 2 years I started having trouble with most of the seasonal vehicles. My smart charger (with AGM settings) would not charge ANY of them because it gave a "sulfated" error. I bought a small charger specifically with desulfating settings and continued charging them that way. Even though following the directions to desulfate, the smart charger would never bring them to full charge.
After another year, the boat battery was completely dead and would not accept a charge. It was just out of warranty, so I got nothing for it. I replaced it with a Die Hard marine dual purpose battery, that is now in its 6th year and shows no signs of slowing down.
As of today I have only 1 remaining AGM and its in my lawn tractor. The smart charger won't charge it, but it is still turning the starter so I guess it'll be OK for awhile. By voltage testing its barely at a 70% charge right after charging.
In contrast, my old classic car that is only driven a couple hundred miles a year has a 2002 Die Hard std auto wet cell (no kidding - its 13 years old) that is still going strong with NO maintenance. I DO check fluid levels once a year, but it has never been out of the vehicle and its never been on a charger.
I would say I am anal about maintenance. The wet ones are checked and filled as necessary, and all seasonal batteries are charged monthly during the Winter.
Sorry to be so wordy. I'll continue to buy an AGM for my 'ski (for other reasons), but not for anything else. In the past, all my boat or auto wet batteries lasted me 6-8 years. I just can't claim that kind of success with an AGM, so for me its just not cost effective.
