[Denvercoder9]

Not OP, but with supercapacitors you're talking about a wildly different amount of energy. A 5F/5V cap stores about 62 J, while a 2500mAh 1.2V AA battery stores 10 kJ. With three of them you can store almost 500x as much energy.

[ruslan]

You don't need that much of energy to keep CMOS memory and RTC clock running. The battery will self-discharge way before it's exhausted by the load. IMHO.