There's probably supercaps in there somewhere, but just incidentally as something that came along with some RTC. I think the very poor energy density would make them undesirable for anything that requires storing significant amounts of energy. They are comparable to lead acid batteries. Lithium batteries will deteriorate, yes, but they start off storing much more energy for a given mass.
A Maxwell BCAP0150 puts 150 F in a 32 g package. Rated operating voltage is 2.7 V at 65 C, 2.3 V at 85 C. Assuming 2.3 V full charge with useful discharge down to 1 V, that's 320 J of useful stored energy, just over 10 kJ/kg. Lithium ion batteries are generally in the range 360-900 kJ/kg. A 500 kJ/kg Li-ion battery would need to degrade to 1/50th its normal capacity to become worse than an equivalent mass supercapacitor. If cycle count is enough of a concern, you might look into other battery chemistries before supercapacitors, such as nickel-hydrogen or even nickel-iron batteries.
