Nitecore is somewhat accepted as the best lightweight battery, but they aren't cheap.
10Ah battery is $60, 5.9oz. the 20Ah is 10.2oz and $100. Unlike the Hasbro, it comes close to its rated specification.
My backpacking trips have definitely not needed 20Ah. For two or three nights I can usually get by with a 5000mah, if I shutdown at night and frequently use airplane mode. And my phones are usually getting on, don't have Greta battery life.
replies(2):