Optima batteries can last up to 7 years
[QUOTE=adriancretired;553000]i have an optima starting battery in my boat. i bought the boat used in 2010, and the battery is still holding up. my motor is a 90 hp mercury. the boat had an optima trolling motor battery in it too, but it only lasted a year or two after i got the boat. the boat and battery sits outside all year. its the best battery ive ever had, but im sure my 90hp is a lot easier to crank than your motor.[/QUOTE]
I replaced my two optima batteries after 7 years of use. I still have the old ones in the house and they are still taking charge.
I put two bigger Optima in my boat to replace the two I took out. One was the starting battery and the other was for the trolling motor.
I charged them back up right after ever use. They will stay charged for a long time and are easier to charge up than regular batteries. And they are much more resistant to vibrations compared to regular lead acid type batteries.
What type of motor did you use them with?
[QUOTE=SteveM4A1;553109]The battery depends upon the outboard. If you are using an Optimax, the Optima likely won't cut it. I had 3 Optima 31's go bad in 3 years. Needless to say, I was not happy with them and will never buy them again. But there are plenty of people out there that get good results from them. Personally, I buy good batteries now that cost a lot, because I have been stranded enough to not let it happen again. It is worth it to me to have that piece of mind that a quality battery brings.[/QUOTE]
Was there anything wrong with the boat or wiring or the motor? My Johnson 35HP Motor has a charging system that outputs a DC current into my battery to keep it charged up. A couple of times a diode in the system went bad and the charging system didn't work. The battery went down and I had to use an external battery charger to get the battery charged back up until I could replace the diode in the motor. After that the battery stayed charged.