Yes, there are plenty of things not accounted for in our expense evaluation, but if all these other things have been included, they would only further reduce the total per use expense properly under ten cents per use. Firstly, newer rechargeable batteries can very easily supply 30% to 50% extra energy than common alkaline disposable batteries. Secondly, in the event you acquire four extra rechargeable batteries at 16 US or significantly less, your per use expense for these supplementary rechargeable batteries falls to significantly less than four cents per use ( you already possess the charger ! ). Thirdly, electricity charges are extremely tiny taking into consideration a number of the best AA rechargeable batteries will deliver three Watt hours or extra and electricity in the grid will expense you six to ten cents per 1000 Watts per hour. Fourthly, a major notch rechargeable battery may not final 1000 utilizes but will surely final a great deal greater than one hundred utilizes.