Pulsetech Xc100-P Xtreme Charge Battery Charger $100
While you can't always prevent a battery from losing its charge, the Xtreme Charge Battery Charger makes it as unlikely as possible. It juices up discharged batteries, maintains the charge and even helps extend battery life with its patented Pulse Technology. PulseTech claims that 80 percent of batteries die from lead sulfate buildup on the battery plates. The company says that pulsing the current will reduce and occasionally reverse sulfation, thus restoring a battery to useful condition.