I hate any device that takes batteries and requires me to change them more than once a year. (Remote controls are ok, flashlights are not, and remote control cars are straight out.)
Like me, many of you have probably wondered what the deal is with all the different types of batteries -- AA, AAA, C, D, 9V, and so forth. So here's a handy table I stole from Wikipedia's entry on batteries.
| US | IEC | ANSI | Other | Shape | Voltage |
|---|---|---|---|---|---|
| N | LR1 | 910A | cylinder L 30.2 mm, D 12 mm | 1.5 V | |
| AAAA | 25A | MN2500 | cylinder L 42 mm, D 8 mm | 1.5 V | |
| AAA | LR03 | 24A | R03,MN2400, AM4,UM4,HP16,micro | cylinder L 44.5 mm, D 10.5 mm | 1.5 V |
| AA | LR6 | 15A | R6,MN1500, AM3,UM3,HP7,mignon | cylinder L 50 mm, D 14.2 mm | 1.5 V |
| A | filament supply in old radio receivers | cylinder L 50 mm, D 17 mm | 1.5 V | ||
| B | plate supply in old radio receivers | 90 V | |||
| C | LR14 | 14A | R14,UM2,MN1400,HP11,baby | cylinder L 43 mm, D 23 mm | 1.5 V |
| D | LR20 | 13A | R20,MN1300,UM1,HP2,mono | cylinder L 58 mm, D 33 mm | 1.5 V |
| F | cylinder L 87 mm, D 32 mm | 1.5 V | |||
| G | cylinder L 105 mm, D 32 mm | 1.5 V | |||
| J | cylinder L 150 mm, D 32 mm | 1.5 V | |||
| lantern,996 | rectangular prism 68 mm square × 115 mm | 6 V (note) | |||
| PP3 | 6L6R1 | 1604A | 6F22,6R61,MN1604 | rectangular prism 48 mm × 25 mm × 15mm | 9 V (note) |
| PP9 | 6F100 | 1603 | rectangular prism 51.6mm × 65.1 mm × 80.2 mm high | 9 V (note) | |
| 4R25X | 908 | MN908 | square prism 110 mm high × 67.7 mm square, spring terminals | 6 V (note) | |
| 4R25 | 915 | square prism 110 mm high × 67.7 mm square, screw terminals | 6 V (note) | ||
| 4LR25-2 | 918A | MN918 | rectangular prism 127 mm × 136.5 mm × 73 mm high, screw terminals | 6 V (note) | |
| PC926 | rectangular prism 127 mm × 136.5 mm × 73 mm high, screw terminals | 12 V (note) |
Battery capacity is measured in Amp-hours, or more commonly, mAh (milliamp-hours). AAA batteries typically output between 900 and 1,155 mAh at 1.5 volts, and the larger cells in the same series have the same voltage (as shown in the table above) and larger capacities (proportional to their larger volume). (A battery with 1,000 mAh can sustain a current of 10 mA for 100 hours, or 100 mA for 10 hours.)
From what I can find, the capacity of various brands of batteries -- like Duracell, Energizer, Rayovac, Sanyo, or whatever -- is pretty much the same; battery capacity is almost entirely determined by the type of chemical technology used. Here's an excellent chart of capacity and weight comparisons for various types of Nickel Metal Hydride (NiMH) and Nickel Cadmium (Nicad) rechargables. Here's an article on how batteries work. Here's a history of nonrechargable batteries from the Electrochemistry Encyclopedia. Here's a page that explains why nonrechargable batteries have a much higher capacity than rechargables. Here are datasheets for Duracell and Energizer batteries.
