Force mode: to activate low voltage "dead" lead acid battery or wake up "dead" LiFePO4 battery Safe: connection spark free, reverse polarity, short circuit and internal overheat protection Charges and maintains 3 batteries with different voltage and technologies at once Adaptable charging algorithm for lead acid and lithium (LiFePO4) Auto detect lead acid or lithium technology Easy to use: connect and forget Battery size: up to 40Ah. CHARGER BK20 12V 3X2A