How do folks keep their lead acid batteries alive over the winter ? I've a cheapo charger (red light/green light) that i've used to revive the battery every month or so but was thinking a modern "smart" charger might be a better bet. Can these things be safely left alone on trickle charge for 4 months or better to try revive the battery in the spring ? Can a lead acid battery be successfully brought back to full charge from dead ?