Energizer responded to Are Energizer Rechargeable “D” Batteries “AAs” In Disguise? by explaining why D size rechargeable batteries are made the way they are:
I am writing on behalf of Energizer and would just like to provide some answers to the questions posed in the blog.
All Energizer NiMH batteries have the mAh capacity rating on the label. There is no deception concerning the battery capacity and the D size designation only represents the batteries physical dimensions. We have found that most D size devices will work satisfactorily with the Energizer NiMH batteries and the rechargeability of the product is the true advantage of this chemistry.
D size rechargeable batteries have historically used a smaller internal unit cell. The main driving force behind this design is to keep the battery affordable to the average consumer. High capacity rechargeable batteries are more expensive than our standard rechargeable D size battery due to the increased volume of materials needed. In addition, they require a higher capacity charger to deliver acceptable recharging times which are also more expensive. Our research indicates that the high upfront cost for high capacity rechargeable batteries and special charger would discourage many users from trying these batteries.
Clearly a high capacity D size NiMH battery would be beneficial in certain applications but we have found that the market for this type of battery is minimal due to overall cost. Energizer will continue to evaluate this market and look for a cost effective opportunity for higher capacity NiMH batteries.
Thanks Energizer. It should also be noted that while the source of the original material, Mike Adams at his site Natural News, is not incorrect in stating the capacity of his Enegergizer D batteries, the fact that he includes a link to batteries you can buy directly from him in his own post means that you should evaluate his claims as ad copy, not as journalism. In addition, links on his site to his ebooks about beating swine and bird flu through herbal remedies further calls into question his reliability as a credible source. Furthermore, the practice of including smaller batteries in a larger shell is common practice, not a deception. If you open up a lantern battery, for example, you’ll find four smaller cells inside.
Battery sizes are really about form-factor these days. Consumers need to go beyond the big letters on the package. Remember to check the label first and see if the the mAh capacity meets your needs, and know that other vendors exist beyond what’s in the supermarket checkout aisle. Check out the comments section on the original post for a robust and delightfully wonky discussion about where how and why to buy the best batteries.