Charging the Battery
Smart Engine's Lithium Polymer battery comes partially charged and the train is ready to play right out of the box. When the battery's charge level gets low, the top LED starts to slowly pulse in red. At this point, the engine may have only 5-10 minutes of play time remaining and the battery needs to be recharged.
To charge the battery, turn off the engine and plug the included micro-USB cable into the engine's USB port located in its rear, just behind the Power Button. Connect the USB cable into any standard USB port (e.g. USB wall charger or hub, USB port in a computer, etc.). Note that the engine's battery will also charge when the engine is connected to a USB outlet while still powered on. But the battery will charge significantly faster when the engine is powered down.
When the engine starts charging, the charger LED located just behind the Power Button will turn on and glow in red color. It will turn green when the battery is fully charged. Note that it takes about an hour to fully charge the battery from a completely empty state. The continuous play time on a single charge is typically 100+ minutes.