What does the mah mean for batteries and cameras?

Are CR2 batteries interchangeable with 544 batteries for old cameras?

• I found an old Canon AE-1 at a garage sale and the user guide says to use 544 battery. Inside was a 532 battery so they must be interchangeable. Given that these batteries are getting harder to find naturally due to technological "advancements", is a much more readily available CR-2 lithium going to work? At first glance they look approximately the same size.

• Answer:

  Hi thousandpoundgorilla, The 544 battery designation is just a multi-cell version of 4 SR44 silver oxide batteries. You can stack the SR44 (or any other Silver Oxide equivalent) batteries together and they will perform in exactly the same way. I believe the main reason for making the 544 battery was that there were some complaints from consumers after multiple battery configurations resulted in damage to products because of incorrect orientation of one or more cells in a stack. One solution to that is to simply lay a set of properly oriented SR44 cells end to end across a bit of thin cellophane tape and roll them up inside the tape, then trim the tape to make sure each end of the roll will make good electrical contact. You can check the voltage of a stack with a volt meter or battery tester and the reading should be very close to 6.0 volts. If you cannot get a reading or the voltage is less than 5.0 volts you have - 1. One or more bad cells (test each one, they should each read about 1.5 volts) 2. Failed to maintain good contact between the cells in the stack, disassemble and retry 3. Have one or more cells facing the wrong way, disassemble and retry. There are a number of batteries sold as "substitutes" for SR44 cells. To my knowledge ONLY the Silver Oxide batteries provide the correct discharge curve for use in electronic shutters and light meters so using substitute chemistry is NOT recommended. The 532 battery was a special 3.0 volt alkaline battery designed for use in certain Polaroid camera models and would provide only 1/2 the required power of the 544 battery. Also the original 532 battery was a good bit larger in diameter than the SR44 and had "snap" clips, like those found on a typical 9 volt battery, on either end. This battery SHOULD NOT be used in any AE-1 unless the camera was modified somehow to accommodate that type of battery. The CR2 Battery is a 3.0 volt photo Lithium chemistry battery. This battery would have better discharge characteristics than an alkaline battery but is designed primarily for high energy drains such as digital camera display screens and flash units. Again it would only provide 1/2 the voltage required by the AE-1. This battery is also available in a 3.2 volt rechargeable version using Lithium Ion chemistry. These voltage variations can make light meter's behave in a very unpredictable fashion with older cameras such as the AE-1. Hope that helps. Good luck. Email me if you need more information or assistance.