The trick to making any battery last is to give it some exercise. The absolute worst thing that can happen to it is to sit dormant. If a battery is discharged about 25% of its capacity and recharged frequently, and NOT allowed to bounce around excessively, it should last several years. Keep the connections clean and tight, discharge/recharge often, and don't let it go dead and stay that way, or allow it to sit idle for long periods.
Jerry