How to choose a battery
What battery should I buy for my application?
If you are having trouble finding the right battery, it must be for a more demanding application than to power a wall clock or a TV remote control. A high drain device, such as a digital camera, a portable CD player, an MP3 player, or even the common flashlight requires a battery that can supply high current. The current required may be more than the recommended current load for a given size battery, even four to six times recommended current load. The battery is expected not to lose voltage at the same time, or else the device may quit functioning. Did you know that some digital cameras using four AA batteries need to be supplied with 5 volts from four batteries, or the camera will turn off? This is 1.25 volts per cell. Nickel-metal hydride (NiMH) batteries measure 1.35 volts each, when fresh from their charger. They fall to 1.25 volts in a hurry!
You get what you pay for, Energy and ability to supply high current
On another page of the All About Batteries.com website entitled
we present a table showing which batteries provide the most Energy per unit Volume, the most Energy per Kilogram, and the most Energy per Dollar. Don't take the time to go look at it just yet. You may find the information confusing without further guidance. Summarizing the findings in a nutshell, as applied to AA-sized batteries, the table shows that the most energy per battery cell, 9360 Joules, which is 2.6 Watt-hours, is available from an ordinary Alkaline battery!. Not only that, but the price per Watt-hour is only $0.38 (and could go lower for alkaline batteries found on sale.) In contrast, NiMH batteries of the same size store 1.8 Watt-hour of energy, but cost about $2 per Watt-hour! And with Alkaline batteries, you start with a voltage of 1.55 volts when the batteries are fresh out of the package, a long way from 1.25 volts.
So what is wrong with Alkaline batteries? They are not rechargeable. Oops, that used to be true, but not any longer. A new type of recharger, the
™ safely and conveniently charges all ordinary Alkaline batteries of all sizes, and can simultaneously do nickel-cadmium and nickel-metal hydride batteries of mixed sizes! Owners of digital cameras have found out that the
does a better job of recharging their NiMH batteries than chargers that came with the camera.
How can I assure that the batteries I start with are fresh?
How can I find those hard-to-find battery sizes or sale prices?
Just click on some of the links we have provided to take you to respected suppliers of batteries meeting your requirements. There is little difference in performance between name brand batteries according to tests performed by Consumer Reports magazine. This is contrary to the advertising of the major battery manufacturers. It is probably more dependent on the volume of batteries moving through the store or supplier, so that fresh batteries are available at all times. Many retailers of batteries such as Wal-Mart, Radio Shack, or Walgreens sell batteries marked with the store brand name, but in most cases those batteries have been manufactured by the major battery companies, under subcontract.
At Battery Company
The Source at Circuit City (Canada)
Battery economy tip: Save energy and money by turning off unnecessary functions
Although this tip applies directly to digital cameras, you can apply the same principles to flashlights and audio players. In a digital camera, the highest drain on batteries comes from the LCD screen that shows the composition of the picture about to be taken, or the previous image. Turn it off when it is not in use. Use the optical viewfinder instead. The next highest drain is from an auto focus motor driving the lens. In some cameras it can be switched from continuous operation to operation only when the shutter button is depressed halfway. Continuous operation wastes energy. Finally, charging up the flash between pictures uses energy. If the distance to the subject is over 10 meters, the light from the flash is wasted, so take the picture without flash. All those thousands of flashes seen coming from the fans seated in packed stadiums are from people who don't know this.
This might be a good time to get acquainted with the tables showing the available energy from various battery types, shown in
Battery energy tables.