Optimate3 Battery Charger  Diagnoses, recovers, charges, checks and maintains batteries safely for months Advanced fully automatic battery charger and maintainer for all 12V lead-acid batteries from 2.5 to 28 ampere-hours capacity Includes sealed and conventional batteries for motorcycles and similar vehicles, such as dry-charged MF and sealed wet maintenance-free types and sealed deep-cycle gel batteries used in backup power and other applications requiring a steady delivery of power Unique diagnostic function automatically identifies deeply discharged (sulphated) batteries and applies a controlled high voltage with small fixed current for a limited period to recover them.