4700uF 16V Electrolytic Capacitor. A standard workhorse for filtering power spikes!
This higher voltage version is used in the Junkbots mini-sumo. This capacitor is less appropriate for solar applications where weight is best kept to a minimum.
The increase in voltage range comes at a sizable increase in volume. 16mm diameter x 31mm long (0.640" diameter x 1.215" long).