Letter Re: AA Cells and Mobile Power

There was a discussion about batteries a few days back on SurvivalBlog. The writer advocated using AA NiMH cells almost exclusively, with adapters for devices requiring C and D cells. While I do agree that this is a good approach for some devices, there is certainly some merit to having full size 10 Amp Hour (10,000 MAH) batteries in high [current] draw or long term use devices. Not only is capacity
significantly higher on larger cells, but the maximum safe current draw is higher too.

Good NiMH C cells have 2-to-3 times the capacity of AA cells, and NiMH D cells have 4-to-5 times the capacity of AA cells. They can be charged in a reasonable timeframe on a good quality charger like the MAHA MH-C801D. If you shop carefully you can find 10AH NiMH low self discharge D cells for around $10 each (As an example, see Overstock.com). Thanks, – BR

JWR Replies: I recommend that SurvivalBlog readers be very careful when shopping for size C and D NiCD and NiMH batteries. Many of the batteries on the market have no more capacity than a size AA. (With those, essentially you are getting the same “guts” used in a size AA cell, but just in a bigger “can.”) Look carefully and the MaH ratings before you buy! Also, be sure to buy only brands (such as Sanyo’s ENELOOP) that have “Low Self Discharge” (LSD) rates.