Excuse the abbreviations.
In USN, we use nonrecharge batts. If we upgraded AA batts to rechargebale, the savings could be over a $1 million.
Current batt cost as low as $.28/batt.
Approx cost of recharge batt is about $4/batt.
Assume = run time:
-Discharge rate nonrecharge 7.8hrs(http://data.energizer.com/PDFs/EN91.pdf)
-Discharge rate recharge 8.8hrs(http://data.energizer.com/PDFs/nh15-2000.pdf)
The Energizer website says the battery can be recharged "several hundred times"(http://data.energizer.com/PDFs/nickelmetalhydride_appman.pdf). I will assume 200 recharges.
One recharge =14 normal.
Let us say for a min, for $4, a recharge batt can replace 200 nonrecharge batts. Saving 200 x .28 = $56/batt over the batts life(probably much more).
For example we'll say only 10k sailors out of the entire navy use 2 batteries per week. That will be 10ksailors x 2batt/wk x 52wks = 1.04 million batts.
1040000 batts per yr x 0.28 dollars = $291000 per year.
If we replace the nonrecharge with recharge we have 10ksailors x 2 batts/wk x $4 = $80000 for the first year,recharge over weekend.
A min 200 charges then for 1 charge per week x 52 wks/yr = 52 charges/yr. At that rate it will take about 4 yrs before more batteries will be purchased.
Over the 4 yr period, nonrecharge batts yeild 4yrs x $291000/yr =$1.16 million. Where recharge batteries will cost only $80,000 ovwer that same time frame. A savings of 1.08 million dollars.
An initial investment of batt charges forthe same senario will be on average approx $20. 10k sailors x $20= $200000.
Initially and over an 8 year period yields a savings of $1.96 mill.
This only accounted for AA batts use with 10k sailors and a min 200 recharge. The # of sailors that use AA batteries is higher, but the # of batteries per week is probably lower. So the #s would probably be different but with the same % savings. Plus this could be spread throughout the entire Gov't. The savings would add up significantly.