Duracell DPP-300EP air compressor works great

The portable starter came charged and just needed to be topped off for an hour or so with the included AC charger (the charge status is indicated by a series of LED lights). The air compressor takes about 20 seconds to increase tire pressure by 1 psi, and is great for keeping your tires at the right pressure without going to a gas station and paying for air. (I haven't needed to use the starter or inverter functions yet.)