Last updated 11 April 2008
Let's be blunt: digital cameras can use up batteries at an appalling rate, especially if you choose the wrong kind of batteries. You can drain a set of AAs in as little as fifteen minutes! But don't despair—there are batteries that can keep your camera going for hours. You just have to know what to ask for, and that's what I'll talk about here.
When it comes to AA batteries, the kind many digital cameras use, you have your choice of almost half a dozen "families" or types. Which one is best for you depends on your shooting style (more on that later). Before I summarize their characteristics, here's a quick word about power ratings. Batteries are rated in milliampere-hours (mAh). This is a measure of how much electrical current a battery can put out—and for how long.
What does that mean in practical terms? Well, cameras vary in their power usage, but let's say your camera uses about 1,000 milliamperes (mA) when it's running with the LCD lit (see Martin Rommel's real-world current consumption figures for the QuickTake 200). In that case, if you had a set of 1,000 milliampere-hour (mAh) batteries in the camera, you could figure on getting about an hour of running time out of them. 2,000 mAh batteries would give you twice as much time, and so on. Alkaline batteries are the sole exception to this handy rule of thumb: they have high mAh ratings, but deliver very short operating times. (We'll see why in a minute.)
With that in mind, let's look at your choices:
Here's a summary of AA battery characteristics:
1 when purchased in a 4-pack (cheaper when bought in bulk, obviously)
Obviously you're going to save money in the long run with NiMH rechargeables. But it's not that simple. As mentioned above, rechargeable batteries lose a little power every day (about 1% for NiCds, slightly more for NiMH batteries) even if you don't use them. That means a fully charged set will drop to unusable voltage levels in a month or two—even if the camera's just sitting on a shelf! They're not permanently dead, of course—but they will need a recharge before you can use them.
Thus if your shooting habits fall into the Christmas/Thanksgiving/birthday pattern and the camera stays in the closet the rest of the time, NiCd or standard NiMH batteries are likely to be dead when you need 'em. If that's your style, you have two choices.
Hybrid NiMH cells such as Sanyo's Eneloop will stay usable for up to a year, so they're probably the best bet for most casual/occasional users. But if you want the maximum shelf life, disposable lithium batteries will hold their charge from seven to ten years on the shelf. (Alkalines have a shelf life of two to three years, but they perform so poorly in digital cameras that I don't recommend them for this use.)
On the other hand, if you use your camera frequently, here's a good strategy: use rechargeable, high-capacity NiMH batteries for regular shooting, but always carry a spare set of hybrid NiMH or disposable lithium batteries with you, in case the rechargeables poop out in the middle of a shooting session. (You know it's gonna happen sooner or later!) The lithiums make ideal emergency batteries, because as long as you don't use them, they'll hold their juice for many years—and meanwhile you can save a lot of money by relying on the rechargeables for day-to-day use.
A note about battery usage: heed those warnings you see about taking the batteries out of the camera if you are going to be leaving it on the shelf for a few months. Unused batteries—especially alkalines—can leak caustic chemicals that have the potential to destroy your camera's delicate innards. One reader lost his QuickTake 200 this way. Don't let it happen to you!
Even the best AA batteries will only get you a couple hours of operating time. But here's a great idea suggested by Ken Spencer: make a high-capacity rechargeable battery beltpack for your camera, using rechargeable D cells. Even cheap NiCd D cells store 5,000 mAh, and the better NiMH D cells pack a whopping 10,000-11,000 mAh!
Here's how to build your own super-powered battery beltpack. Take a set of rechargeable D cells and stick 'em into a battery holder (Radio Shack #270-396, $1.79). Put the holder in an inexpensive fanny pack—that's "bum bag" to you English folks—($5-$10 at any department store) and add a short cable terminated with the appropriate DC power plug. Voilà! You've got yourself a super-powered rechargeable battery pack for your camera!
Another possibility—if you're really power-hungry—is to use a single sealed lead-acid battery. These are widely available at surplus houses and Radio Shack in a variety of voltages. (Make sure you match your camera's requirements, of course!) One of these "gel cells" fits nicely into a belt pack and will power the camera all day.Important tips for any home-made battery pack:
If you're using rechargeables, you'll need a charger—and not all chargers are the same! A few bucks will buy you a plain-vanilla charger from Radio Shack or Eveready that will recharge a set of four AA batteries overnight.
If you really want to pamper your batteries, the chargers most often recommended by folks who are knowledgeable about digital cameras are those made by Maha. Their most popular all-purpose model is the MH-C204F, which will charge two or four NiCd or NiMH AA or AAA batteries in a couple of hours. Special sensing circuitry in the Maha chargers allows rapid charging without risking battery damage (see below).
My favorite charger is Maha's MH-C401FS. It has all the same advantages as the 204, but lets you charge one, two, three, or four AAs or AAAs at a time. Each cell is independently monitored, so each cell gets the fastest, safest possible charge. ZBattery sells this unit for $37.95 in an outfit that includes a charger case, battery case, and both 120VAC and 12VDC adapters... so you can charge batteries at home or on the road.
Some companies will sell you rechargers that claim to charge a set of batteries in under an hour. But rapid charging—anything under about two hours—can be tricky. You see, a rechargeable battery is designed to accept current at about 1/10 of the battery's mAh rating. For a typical 2,500 mAh NiMH AA cell, that works out to around 250 mA, so a full charge would take about ten hours. Force-feeding a battery in a shorter time can reduce its lifetime (the total number of charges it can accept) and diminish its capacity as well.
The key factors that damage batteries are heat and overcharging. An "intelligent" charger (like the Maha models mentioned above) will monitor time, current and temperature and ensure that your batteries are charged just as rapidly as is safe—and that they're not overcharged. On the other hand, if you really push it with an inexpensive "one-hour" charger, you can literally fry the batteries, overheating them beyond repair.
Even a slow charger can damage batteries if they're left on charge for days at a time. No battery likes to be overcharged, and you can substantially reduce a battery's lifetime if you make a habit of leaving it in the charger. Nickel metal hydride (NiMH) batteries are especially vulnerable to damage from this kind of long-term "trickle charging," though the Maha chargers are supposedly safe to use in this mode (I haven't tested this). In general, look for a charger that automatically shuts off—or time your charges manually, and take the batteries out when they're done. A little care can reward you with much longer-lasting batteries and save you money.Two more important charging tips:
Wondering whether the NiCd "memory effect" is real? If you want a detailed—but readable—explanation of the electrochemistry of NiCd batteries, Ken Nishimura's NiCd FAQ (Frequently Asked Questions) page will tell you all you ever wanted to know and more.
If you have tips or suggestions about either of these two cameras, or if you've found any accessories I haven't mentioned here, send email to Andy Baird so I can put the information on this page.This website was made with a Macintosh.