This Big Freaking Capacitor is just the trick when you have a lot of current sloshing around your project. They'll help smooth out voltage spikes by providing a little buffering. We use these to help stabilize solar panels on our solar Lipoly charger kit, but they'd also be great with our servo driver boards or on the power connection to our 5V 10A power supply
4700uF capacitance for up to 10V power supplies.
4700uF 10v Electrolytic Capacitor (7:02)