I used to have to buy a new battery every year until I started using Energizer 12Volt Deep Cycle Batteries from Sam's Club. I have used these batteries for 3 years and have not had to replace them yet. I use a fully charged battery for 10 hours straight and still have a strong charge at the end of the day. My boat does not have an alternator, so that is pretty darn good. Pretty amazing battery, try it and let me know what you think.