Sanyo’s Eneloop rechargeable AA batteries

The summary first:

For QRP purposes, these batteries are great as a 10-cell pack. For internally installed AA batteries (such as in the KX1) that limit you to a smaller number of cells, the batteries of choice are non-rechargeable lithium batteries (if money is not a consideration) or non-rechargeable Panasonics Oxyrides (if it is).

What makes Eneloops so special?

In a nutshell, Eneloops are NiMH batteries that retain their charge far, far longer than other NiMH batteries. In so doing, they offer the advantages of a rechargeable cell – economy – without the disadvantages normally associated with NiMH, ie a poor shelf life.

Eneloops can be charged, put away for 6 months and then used with an almost full effect. With other NiMH cells, you must charge before use or suffer the consequences of diminished capacity.

My reason for buying these batteries is due to many wasted alkaline AA batteries I use in my camera flashes. Typically, I’ll use two or three small flashes during a photo session. One flash may fire at near full power, another at some fraction of that. An hour later, the batteries are nearly dead…or not, depending on many things. But not wanting to start my next shoot with used batteries, I throw this set away. Those in the secondary and tertairy flash probably have a lot of life in them but not enough to use for another session, so they get tossed out.

A number of threads on various photography websites mention the Eneloops – all favorably – so I decided to get a 12-pack of my own for use in my flashes.

Graphical Comparison


70F/21C, constant 300 mA discharge rate


There are other NiMH rechargeable batteries that have much more capacity than Eneloops, however they are required to have been recently charged to have retained that capacity prior to their use.

A 10-cell pack of Eneloops would make a great battery for QRP afield use; and an economical one too, without the need to consider whether they were charged two days or two months ago.

I’ll test this last “charge retention” point in three months…