Enter the RYOBI 18V ONE+ System with the 18V ONE+ 4.0 Ah Lithium-Ion Battery. With up to 3X more runtime than the previous model, this lithium-ion battery provides an improved user experience. The new compact design is lighter weight and reduces overall user fatigue. This battery features a high visibility LED fuel gauge to clearly indicate remaining runtime. Fade-free power allows users to optimize the entire charge of the battery in all weather conditions.The 18V ONE+ Lithium-Ion Charger charges all RYOBI 18V Lithium-Ion Batteries, and can charge a 1.5 Ah Battery in as little as 45 minutes. The indicator lights show the status as the battery is charged and maintained. A convenient temperature LED indicates when a battery is too hot or too cold to charge. Energy Save Mode conserves energy when not charging or maintaining batteries.