CTEK M300 General Information Input voltage AC 220-240VAC, 50-60Hz Output voltage Nominal: 12V Efficiency 85% Charging voltage 14.4V, Temperature compensated Charging current 25A max Back current drain* <2Ah per month Ripple** <4% Ambient temperature -20°C to +50°C, output power is reduced automatically at higher temperatures. Cooling Fan Type of charger Eight step, fully automatic, switch mode with pulse maintenance. Type of batteries All types of 12V lead-acid batteries (Wet, MF, AGM, Calcium/Calcium and GEL). Battery capacity 50-500Ah Dimensions (L x W x H) 235x130x65mm Insulation IP 44 (Outdoor use)*** Weight 1.4kg Cable length: Mains to charger - 1.8mtr Charger to battery - 4.0mtr *) Back current drain is what drains the battery if the charger is connected without the power cord connected. **) Ripple denotes the amount of interference there is to the current and voltage. A high current ripple heats the battery and shortens its life. A linear charger has a current ripple of 70 - 400% which is much larger than the maximum 5% for a modern sealed battery. Voltage ripple could harm other equipment, which is connected to the battery. The M300 delivers voltage and current with very low ripple. The battery gains a long service life and there is no risk of damage to other electronic devices connected to the battery. ***) IP 44 cannot be guaranteed unless the charger is positioned with its top or long side facing up. For the technical data of the M300 starter, please see the XS 800. The CTEK M300 (25A) is a powerful and complete 8-step, fully-automatic, switch mode battery charger package for dual battery banks, which analyses, charges and maintains all types of boat batteries.