The 12V Max slide batteries offer improved high-capacity, ease of use and durability like styled like the 18V range. The Makita 12V Max 2.0Ah Slide Battery, BL1021B-L, also features a battery fuel gauge indicator that display battery charge via four LED lights located on the back of the battery. The battery fuel gauge has been located on the back of the battery ensuring convenience for the user - being able to quickly view the battery charge from the back of the tool, without having to stop and turn the tool around. The benefits of slide-type over cassette type batteries are a more stable contact between battery and tool - multiple contact points ensure stable connection even with the tool under extreme vibration, same ergonomic design as 18V LXT products, and battery terminals are protected from shorting out when thrown into tool bags. Using a slide battery allows the 12V Max range of tools to have a more slender, ergonomically designed handles - smaller and more comfortable than handles of cassette style batteries which have to be designed around the battery. The DC10SB provides rapid charge times for the 12V MAX battery platform, being able to fully charge a 1.5Ah battery in 22 minutes. Stand-by time is greatly reduced as the DC10SB is equipped with a built-in cooling fan. This fan effectively cools down ever battery cell with the forced air cooling system. The DC18SB also includes a charging status indicator to show the charging status of the battery. This is shown in 2 stages; Less than 80% and 80% or more.