I've always had good luck with a plain old Budget Batteries battery. I watch the fluid level carefully and keep the terminals clean. They seem to last 3-4 years. Obviously you can spend a BUNCH more money, and it may be worth it if you live in an area with severe climate changes. I prefer a sealed battery (maintenance free) but they are about twice the cost. NOTE: if you have a battery with a vent for offgassing during high charge periods, make sure you VENT it away from the engine compartment. I used a length of 5/32 vinyl hose from the auto parts store and threaded it under the car, fastened with a cable tie. Motorcycle batteries commonly have this kind of vent and it's probably common among the cheaper set. NO VENT = CORROSION. I caught mine in time, hence the vent hose.