The BOSCH SKC36-01 36V Lithium-Ion Battery and Charger Starter Kit features two Bosch BAT838 4.0 Ah 36 V batteries and the BC3680 36 V fast charger. The BAT838 battery delivers 50 percent more runtime than the previous generation 36 Volt battery; when projects are under time constraints, battery runtime can be a difference maker. Bosch’s CoolPack technology delivers up to 100 percent more recharge life versus other battery packs. The Bosch BC3680 charger can charge a spent BAT838 battery in 45 minutes, for more productivity and better RYOBI. The smallest and lightest charger in its class powers the cells safely. BOSCH SKC36-01 36V Lithium-Ion Battery and Charger Starter Kit has battery-protection systems, including trickle charge the first 80 percent is very fast, while the remaining 20 percent of the charge is standard speed. Another protection measure is a cooling fan, which prevents overheating while charging. BOSCH SKC36-01 36V Lithium-Ion Battery and Charger Starter Kit provides a charging status indicator, and it is compatible with 18 V Bosch batteries as well.