Lithion-ion Power System for Small Satellites
Batteries powering satellites or spacecraft must be rugged enough to withstand the severe vibrations of launch. Once the craft is deployed, these batteries must operate in extreme conditions of heat and cold and solar radiation. And, they need to work in a vacuum without leaking or exploding. There are many types of batteries: carbon-zinc, lead-acid, nickel-cadmium,
nickel-hydrogen, silver zinc, alkaline, and lithium-ion to name a few.
Most batteries currently used in space flight are nickel-cadmium. Also called NI-Cad, these batteries are charged by solar cells that convert the Sun's energy to electricity. But Ni-Cad batteries eventually wear out and aren't rechargeable. Space Technology 5's small-sats will use Lithion-ion,
or Li-ion, batteries, which use chemicals to store energy. And each cell of a Li-ion battery is equipped with a control circuit to limit the voltage peaks during charge and to prevent the voltage from dropping too low on discharge. This control circuit also limits the maximum charge and discharge current.