1 F at 5.5 V — the energy buffer for a backup or peak-power hold-up
The KYOCERA AVX SCMR18F105PSBA0 is a 1 F supercapacitor rated at 5.5 V, from the SCM series. This is the capacitance and voltage that define the stored energy: 1 F at 5.5 V delivers about 15 J, enough to ride through a brief mains dropout or supply a short burst of peak current that the main power rail cannot source alone. The 250 mOhm ESR at 1 kHz sets the internal resistance that limits how fast the cap can deliver that energy. For a 1 F part, 250 mOhm is a middle-ground figure — it handles a few hundred milliamps of ripple without excessive self-heating, but a high-current pulse (several amps) will see a significant voltage drop across the ESR and waste energy as heat.
Through-hole radial can — board-fit and layout
The part comes in a radial, through-hole can with PC pin termination and a lead spacing of 0.453" (11.50 mm). Mounting it requires two 1.0 mm holes on an 11.50 mm pitch — a standard footprint for this can size. The tolerance is 0%, +100% — meaning the actual capacitance is at least 1 F and can be up to 2 F. This wide upper spec is normal for supercapacitors and means the stored energy can vary by a factor of two from part to part. The circuit must tolerate that spread; a constant-current load or a voltage-monitoring cutoff is more reliable than a fixed timing resistor.
Temperature range and lifetime — where it works and for how long
Rated for -40°C to 65°C operating temperature, with a lifetime of 1000 hours at 65°C. At lower temperatures the lifetime extends significantly — every 10°C drop roughly doubles the expected life. At 45°C the part is good for about 4000 hours; at 25°C, well over 10,000 hours. The 65°C ceiling means it is not suited for under-hood or high-temp industrial environments, but it is fine for most indoor electronics, telecom gear, and consumer appliances. The voltage rating is 5.5 V — do not exceed this even momentarily. Supercapacitors have a sharp wear-out mechanism above rated voltage; a 6 V transient can halve the lifetime. A series resistor or a zener clamp on the rail is cheap insurance.