Desciption For X2 BL1840 Features include: Unbeatable 36 minute charge time. Up to 33% extra runtime and extended battery life. Same size and weight as 3.0Ah BL1830. Works with your current Li-ion chargers. Computer controlled optimum charging. Compatible with starred terminal machines. Compatible with yellow terminal machines. Cooling System for max battery life. Battery protection circuit. LXT Lithium-Ion battery and optimum charging system produces 280 percent total lifetime work with 2x more cycles. 5x Lower self-discharge keeps battery cells active and ready for use, even after long periods of storage. Charging at any time will have no effect on the battery. Built-in shock absorbing features protect the battery. Sixteen firm holding contact terminals reduce the risk of power loss/fluctuation in high vibration work environments. Battery's built-in Memory Chip communicates with the charger to maximize battery life using 3 Active Controls (Current, Voltage Thermal). Battery suitable for all Makita li-ion LXT 18 volt machines. Desciption For DC18SD In addition to the DR18RC we now have the DC18SD charger available. The Makita DC18SD 240V Li-ion 9.6v - 18v 30-60 Minute Charger uses a CPU to communicate with the batteries built in memory chip during a charge cycle, which analyses the data stored in the battery chip to decide on the best charging method at that time. This innovative technology results in longer battery life. This charger is suitable of charging up to 3.0ah Batteries only. Built in sounds on the DC18SD let you know charging status and completion. Makita Forced Air Cooling Fan technology cools the battery during charging by forcing cool air through the battery' s built-in air vents prolonging the life of the battery.