This Einhell Power X-Change 5.2ah Starter Battery Twin Pack contains: 2 x PX-BAT5 Power X-Change Batteries 18V 5.2Ah Li-ion 1 x Power X-Change 3ah Charger The Einhell Power X-Change Li-ion Batteries are controlled by a micro-processor, which monitors its key parameters such as temperature, voltage and current strength. This provides effective protection against overheating and ensures the right balance for optimum operating conditions. The battery can be charged irrespective of its charge level. An automatic check establishes conditions on which the charging process depends. In normal conditions, for example, the high-speed charging process is started directly. In other conditions, e.g. extreme cold or exhaustive discharge, gentle charging is performed at reduced current strength. This charging method protects the battery and is essential for ensuring a long service life. The intelligent charge control system controls each battery cell individually, ensuring each cell is fully