My last one, that is still in the older boat, lasted 7 1/2 years. The only reason it's going bad is because I didn't use the older boat for 8 months, and I had the batteries on the trickle charger/maintainer charger, but I didn't check the battery water and it got too low, ruining the battery. It still works, it's just down on volts so the electric motor doesn't work as powerful or as long. Been that way all summer now. I'll get a new one come spring.