Charge time: 15 to 22 minutes. 3 Active controls system (current, voltage and temperature) provides an optimal charge and ensures battery cannot be overcharged or overheated during the charging process. Central Processing Unit (CPU) in battery communicates with charger to analyze battery and charge according to its unique condition. Forced air cooling fan keeps battery at optimum charging temperature and prevents over heating. Digital power display indicates condition of battery and current charge level.