600 mF energy buffer at 9 V — the parametric anchor
The SCMR18L604SRBB0 is a 600 mF supercapacitor from the KYOCERA AVX SCM series, rated at 9 V with a -10%/+30% capacitance tolerance. The 9 V rating is higher than the common 2.5-2.7 V cell voltage, meaning a single part can serve a 5 V or 9 V rail without stacking multiple cells in series — saving board space and balancing circuitry. The 400 mOhm ESR at 1 kHz defines the peak current the capacitor can deliver into a load transient. For a 9 V rail dropping to 5 V under a 1 A pulse, the ESR contributes 0.4 V of the voltage drop — the rest is the capacitance discharge over the pulse width. This matters for hold-up or backup applications where the load current profile is known.
Through-hole radial can — board-fit and storage
The 0.531" (13.50 mm) lead spacing fits standard 0.5" pitch prototyping boards and many existing supercapacitor footprints. The radial can is not moisture-sensitive — store it on the shelf without dry-pack concerns. Operating temperature spans -40°C to 65°C with a rated lifetime of 1000 hours at 65°C. At lower ambient temperatures the service life extends significantly — the 1000-hour figure at 65°C is the accelerated test condition; at 40°C the expected life is several times longer, following the Arrhenius relationship typical for electrolytic-based supercapacitors.