This Makita Power Source kit will be a welcome addition to anyone with a full kit of Makita Li-Ion cordless tools who regularly finds they are short of batteries and chargers. It comes complete with a Makpac carry case with inlay insert that holds up to 4 batteries and a charger. This Power Source Set Includes 4 x 5.0ah BL1850 Lithium Ion Batteries 1 x DC18RD Dual Port Charger 1 x Makpac Case with Inlay Features of the BL1850 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. 45 Minute Charge Time The Makita 18v 5.0Ah Li-ion batteries charge with existing DC18RA and DC18RC chargers with an unbeatable 45 minute charge time. Through this two way communication between charger and battery, the charger can recognise the battery and recall its charging history analyse the batteries condition and usage and charge the battery accordingly. Makita Star Battery Protection The demanding applications you take on every day are also demanding on your cordless tools and batteries. You rely on your tools, so Makita created STAR Protection Computer Controls . STAR Protection is communication technology that allows the tool and battery to monitor conditions and exchange data in real time to protect against Overloading, Over-Discharging and Over-heating. Look for Makita tools and batteries with the STAR and get these protection features. Makita Star Battery - Overl