The truth is that the Energizer lithiums are probably the best small batteries you can buy. And yes they are a direct replacement for standard pencil batteries. And no, they don't have little bucks inside them.
The AA type present 1.72V open circuit, and can source >4 amps shorted. They also work very well in extreme cold, although the standard advice is to keep them inside your clothing /sleeping bag. The only type I carry for survival gear. Expensive though. They top the list for total storage capacity but you pay for it. Good quality alkaline batteries are good for daily use and they can be bought in industrial bulk quantities (Duracell Procell). I would suggest that lithium only makes financial sense for survival /tactical situations like GPS or gun sights.
Life saving tip: Never use rechargeable anything in survival /tactical situations as they are very unreliable. You'll look really stupid in the middle of the Gobi desert trying to fix the buck converter in your dodgy rechargeable lithium batteries.
I've reviewed two relevant (and official) datasheets, one for the above lithiums and one for standard Energizer alkalines. I have to admit to being surprised as to the difference in capacity. I honestly thought that it would be greater.
So for lithium, we have:-
and for a standard alkaline, we have:-
You'll notice that Energizer cunningly have two different styles of graph. So conspiracy theorists might think that this is to obfuscate an easy comparison of capacities. Not me though. The only common discharge profile is at 100mA, giving capacities of ~3500mAh and ~2500mAh respectively. That's only an improvement of 40% over common alkaline chemistry.
Other interesting comparisons can be determined like (lithium v alkaline):-
Energy density: 233 mAh/g compared to 109 mAh/g (+114%)
Money density: 8.7 pence/g compared to 1.6 pence/g (+448%)
- based on March 2018 Amazon(UK) prices.