Chris,
I do the same as you but at 5 yrs. Except for one defective battery that was repalced under warranty, I've never had a battery last less than 5 yrs. And the winters are brutal up here. Heat can be worse on battery life, but you aren't in Fla or So Texas. I'm surprised you only get 3-4 yrs on a battery.
-Dave
My big boat has 4 batteries and my little boat has 2. You have to think about how they are used. They each set for a week then are used to start up the engines and run for maybe 30 minutes. Many times we sit in a cove on the hook for 2 days running tons of electronics, refrigerator, stereo, tv/dvd, water pump, vacu-flush head, ect all day long until we get a low voltage alarm (11 Volts). On the little boat I must start up the engine and run it. On the big boat we have a Kohler 7,300 Watt Genny so it starts up and runs the battery charger.
I have been stuck and so have many of my friends. Nothing like working on a boat when you are drinking cold ones and hanging with the crew so I find I am just money ahead to get new ones from my dealer for about $52 each every three years versus $90 on the lake for a new one.
Yes, I may be able to get more out of them but I have been doing this for 25 years and experience has told me to be preventive on this one.
On my cars and trucks I have been bitten twice. Last time it was on a Sunday at CVS. Went out to start and no go. Nice man offered me a jump and when he hooked it up the + post it broke off. Now I had to call a buddy to come get me, drive me to a parts store, back to the store to put in the battery, then back to my house. I filled up his F-150 so all said and done it cost me $130 for a $75 battery. I could have nearly bought 2 for what that one broken battery post cost me. I let that particular battery go since it was on my Clunker GM Saturn. I should have know better.
To add insult when I got home I had to take the battery back out and wash down and neutralize the battery acid that leaked from the broken post so I got to do that job twice. Again I would have been money ahead if I would have changed it at 3 years.
Chris
