The SCMR18H105PSBB0 is a 1 F supercapacitor rated at 6 V from KYOCERA AVX's SCM series. That 1 F at 6 V stores about 18 J — enough to ride through a 100 ms power dip at a few hundred milliamps, or to supply a peak current burst for a wireless module or actuator. The 250 mOhm ESR at 1 kHz limits how fast you can charge and discharge it. For a 1 A pulse, the internal drop is 250 mV — that is 4% of the rail, so the downstream regulator still sees a clean input. The ESR also governs self-heating during ripple; keep the RMS current below about 1.5 A to stay within the 65°C lifetime rating.
Tolerance and temperature — the two gotchas in a supercap BOM
The 0%, +100% tolerance means a fresh part can measure anywhere from 1 F to 2 F. If your hold-up time calculation assumes exactly 1 F, you get half the backup time on a low-cap unit — design the timing margin assuming the minimum, or the undervoltage lockout trips early. Operating range is -40°C to 65°C, with a rated lifetime of 1000 hours at 65°C. At 45°C ambient the lifetime roughly doubles per 10°C drop, so a 24/7 indoor panel at 40°C sees several thousand hours before the capacitance drifts below spec. Below -20°C the ESR climbs — expect 2-3× the 25°C value at -40°C, which cuts the usable pulse current.
Through-hole radial — board-fit and handling
The radial can measures 18.50 mm long by 9.50 mm wide, with a seated height of 21.50 mm. Lead spacing is 11.50 mm — a standard 0.453-inch grid that fits most 0.2-inch pitch prototyping boards and 2-layer PCBs without a custom footprint. Termination is PC Pins — the leads are tinned copper, solderable with a standard iron. No special reflow profile needed; a 350°C tip for 3-4 seconds per pin is fine. Polarity is marked on the can sleeve; the negative lead is shorter, same as an electrolytic.