Makita 40V MAX XGT Battery and Charger Starter Pack - BL4040DC1. 40V MAX XGT 4 Ah Lithium-Ion Battery. Rapid Optimum Charger. Battery charge level with 4 bright green L.E.D. indicators allows the user to clearly see charge level. XGT 4 Ah battery reaches a full charge in 45 minutes or less. Enhanced cooling system is engineered to maximize battery life. XGT batteries features an advanced design impact-resistant outer case and shock-absorbing inner-liner engineered to protect the battery in harsh jobsite environments. The XGT Rapid Charger's built-in chip thoroughly communicates during the charging process to control current, voltage, and temperature for more efficient charging. The XGT Rapid Charger with dual-fan design circulates air through the battery to cool the battery and circuit board quickly for faster charging. The XGT Rapid Charger's digital display indicates battery charge level (-80 percent, +80 percent, 100 percent). The digital communication within XGT actively monitors and protects against overload, over-discharge and overheating. XGT Tools and Batteries are designed with a multi-layer contact interface for more constant power delivery to take on high-current demands. XGT Batteries feature rigid rails with impact-resistant construction to secure the battery to the tool during high-demand applications