Flight Demonstration of a Hybrid Battery/Supercapacitor Energy Storage System in an Earth Orbiting CubeSat
The JPL/CSUNSat1 project successfully demonstrated a
hybrid ESS consisting of a Li-ion battery and SC technologies
in flight onboard a 2U tumbler CubeSat. Both the
primary and extended mission phases were completed successfully.
The performance characteristics of the payload
hybrid ESS in flight were in excellent agreement with
ground test results, particularly with respect to the percent
of capacity contributions between the Li-ion cell and the
SC. The large differences in internal resistances from
flight experiments as compared to ground tests were attributable
to significant ohmic resistances of the payload battery
interconnects (i.e., leads, connectors, etc.) and not
due to the inherent cell impedances. Despite operating in
LEO, the spacecraft was able to achieve sub-zero temperatures
critical for flight experiments on JPL’s cold capable
hybrid ESS.