I've had a couple in my truck for a year or so now. It's a short time, but I've had no complaints yet. The maintenance issue can be a big thing. The time I'm here I don't want to waste on batteries. What's the best strategy for maintaining them: 1. Keeping them attached to a maintenance device that's on all the time that the power is or 2. Charging them only when they go below a certain threshhold.