I’m sure there have been cost studies; but I am not aware of any. However; you can do a basic comparison on costs yourself. Just be aware that cost is not the only factor that has to be considered when making the decision.
Typical purchase costs:
- A quick look on Amazon has Eveready Gold AAs for $0.39/each (or AmazonBasics AA Performancefor $0.25/each)
- Panasonic Eneloop AAs are listed for about $3/ea
- An inexpensive charger is $23; but a nice charger can run as high as $80 or more. (I’ve qualified that it must charge a single cell or multiples. Most cheap chargers have to charge more than one cell at a time.)
Power contained in each
- Alkaline batteries generally have 2;500 mAh of charge
- NiMH batteries usually only have 1;500 or so of charge.
- An Eneloop battery is usually good for nearly 2000 charge cycles.
The Choice
Given those criteria; the decision seems to be an easy one.
- Alkaline batteries cost $.0001 per 1mAh delivered. ($.25 / 2500mAh)
- Eneloops cost $.000001 per 1mAh delivered. ($3 / 1500mAh / 2000cycles)
- The nice charger only costs $.04/charge cycle over the life of the battery (if you only charged one at a time). That equates to roughly $.00003 per 1mAh delivered from the battery.
The electricity used to run the charger is negligible unless you generate it yourself; but even then; distributed out over the life of the battery; it is still pretty negligible. You would just have a front loaded cost because you have to purchase the charger and solar charger right away in order to use them.
I’ve used very conservative numbers here and you can see that based solely upon “perfect” usage; an alkaline battery can’t even come close to the inexpensive cost of ownership (charger included) of a rechargeable.
Caveats:
- I have never seen anyone get a full 2000 charge cycles out of the battery. They tend to lose them or treat them badly so they don’t get the full usage rating from them. Even so; if you only get 100 charge cycles; they’re still less expensive.
- As good as Eneloop batteries are; they self discharge over time. If you need a battery that retains a charge under non-use conditions and is ready to go now; alkalines are your friend (unless you consider lithium rechargables).
- If your device requires a high current from the battery; NiMh (or lithium) will generally perform better.
