Sealed lead acid battery chargers and maintainers recharge or maintain the charge of SLA batteries so they're ready for use. These trickle chargers supply a slow, constant charge that typically takes hours to reach full capacity. Slow charging reduces the risk of damage to the battery while maximizing the charge level and life cycle. Charging a battery fully replenishes its charge before it's returned to service, while maintaining a battery keeps it at full charge during storage. Sealed lead acid battery chargers and maintainers should match the voltage of the battery being charged. These devices are commonly used by service and repair personnel.