Originally posted by creampuff 6 AA batteries weight more than a single D-LI90 battery.
The D-LI90 holds up better than any AA especially in the cold.
For alkalines and NiMH, yes, but not for primary lithium AAs.
The D-Li90 weighs exactly the same as 6 lithium AA batteries (Energizer). Primary lithium batteries also perform even better than li-ion batteries in cold, rated for high performance down to -40 degrees. A set of six should also last longer than a single charge of the D-Li90 (based on charge capacity and voltage), and you can get more than 3 sets for the price of one.
For long term use, not cost effective, but no better option for backup I would say, especially since they can also be used for other appliances and be found out in the wild much easier.