All-In-One Wall Mount Series PD4045LIK lithium charger Lithium Ion Battery Advantages: Fast charging times – up to 99% in 2.5 hours vs. up to 13 hours for lead acid batteries. Stores 3-4 times the energy of a lead/acid battery in the same space, with less weight. Nearly constant output voltage during discharge. Delivers full power longer to all systems improving performance. Operates over a wide range of temperatures. -4F to +158F. Can charge and discharge thousands of times vs. 300-400 cycles for lead/acid batteries. Retains 80% of charge for 12 months, vs. lead/acid batteries, which discharge to 80% of capacity in only 30 days! No maintenance required…no more adding water.