Specifications: Voltage: 40V Capacity: 4000mAh Battery type: 21700 Li-ion Cell Compatible with: The Makita BL4040 191B26-6 40Vmax 4.0Ah battery is part of the the XGT range. Providing a genuine solution for high demand industrial applications. The higher output batteries along with innovative tool design means it it is also the solution for high demand industrial users as well. The battery is designed with the tough environmental conditions that come along with working on site. The IPX4 rating means that they are water resistant and built to withstand splashes from any angle. Each battery is built with impact absorbing padding and a heavy-duty outer casing. The XGT range of tools and batteries have a built-in program, that provides digital communication between the tool and batteries. XGT is a long term solution. Tips to make it running longer: The newly purchased lithium battery will have a little power, so you can use it directly when you get the battery and recharge after remaining power run out. After 2 to 3 times of normal use, the lithium battery activity can be fully activated. Here is a special reminder: Don't misbelieve the rumors from the salesperson or the Internet: the new lithium battery needs to be activated for up to 12 hours when it is used for the first time. Please don't charge immediately after the battery runs out. Let the battery cool down 10-20 minutes before charging, this is very important. Always remove the battery from your tool when you are assembling parts, making adjustments, cleaning or when not being used for an extended time. Please store it in a dry, clean, cool, away from heat and metal objects.