Digital Camera Batteries

Battery Types

The key points to remember about AA and proprietary batteries are:

• While proprietary batteries offer the advantage of being lighter and more compact, they are substantially more expensive, making the prospect of buying one or two backup sets much less appealing.
• More often than not, AA-compatible cameras ship with disposable alkaline batteries (the type used in most small electronic devices). Unfortunately, digital cameras generally exhibit pathetically short life - less than an hour in extreme cases - when used with these batteries. While alkaline batteries make acceptable emergency backups, particularly if you are traveling with your camera, Digital Camera HQ highly recommends buying at least one set of rechargeable Nickel Metal Hydride (NiMH) batteries and a charger with any camera that ships standard with alkaline AA's. For less than $50 dollars, rechargeable NiMH batteries offer substantially longer life at an affordable price.
• Other options for AA-compatible cameras include non-rechargeable Lithium batteries and rechargeable Nickel Cadmium (NiCD) batteries. While lithium batteries have superior life to alkaline AA's and offer good cold-weather performance, their price and non-rechargeable nature make them less useful than rechargeable NiMH batteries; in addition, certain cameras are not compatible with Lithium cells - be sure to check before using them. NiCD batteries offer the advantage of retaining their charge while unused, unlike NiMH cells, but have shorter lives and need to be discharged completely before recharging, making them inconvenient for most users.

Digital Camera Battery Tips

• A digital camera's LCD screen consumes power at a rapid rate. If battery life is a concern, use the LCD only when necessary.
• Whenever practical, carry at least one set of backup batteries so that a dead set doesn't leave you powerless. This is particularly true if you plan on being away from power outlets for an extended period of time. If you have the money, three sets of batteries are ideal - one for the camera, one carried as backup, and one always being charged.
• Despite their short life, universally-available alkaline AA's can make convenient emergency backups when away from a power source. Though more expensive than alkalines, Lithium batteries also make good emergency backups (check to be sure that your camera is compatible with Lithiums before using them). Since buying a backup proprietary battery can be so expensive, travelers and outdoor enthusiasts should seriously consider AA-compatible cameras.
• Rechargeable NiMH batteries will lose their charge even when they are being stored. Be sure to charge them before use, even after relatively brief periods of inactivity.
• Alkaline AA batteries have the nasty habit of leaking when left in a camera for too long. Do not leave alkaline batteries in your camera for prolonged periods of time.

Today’s digital cameras depend on battery power to operate and the camera's LCD monitor and flash can drain your batteries very quickly. If you use the wrong batteries or don’t conserve power you can easily run out of battery power.

The camera you choose normally determines the kinds of batteries you can use. When adding or replacing batteries for your camera, read the manual that came with the camera to be sure you select the correct type.

Many cameras use AA batteries. If this is the case with your camera, your best choice is NiMH (Nickel-Metal Hydride). Nickel-Metal Hydride batteries are rechargeable, environmentally friendly (made from non-toxic materials), and relatively inexpensive. More importantly perhaps, they are designed for high-drain applications such as digital cameras and give you more pictures per charge than any other standard battery type other than the much more expensive lithium ion batteries. If they have a weakness, it's their overall life; lasting only about 400 charge and discharge cycles and also they lose 1 percent of their charge each day they are idle. Nickel-Metal Hydride batteries cost more initially than alkaline batteries but in the long run, you're much better off with NiMH because one NiMH battery will last as long as 500 disposable alkaline batteries.

The best batteries for cameras that accept AA batteries are clearly NiMH (nickel-metal hydride). Lithium batteries last for many years and make a good choice for backups for NiMH rechargeables. Nickel Metal Hydride batteries, which ones are best?

In a pinch you can use alkaline batteries, however don't let their low cost entice you into regular use. Many people buy them for their camera only to discover that they are consumed at a shockingly fast rate. The same is true of rechargeable alkaline batteries. They typically have an even lower capacity than standard alkaline batteries. This means that if a standard alkaline only lasts for a few exposures, a rechargeable alkaline will last for even fewer!

LiIon (Lithium Ion) batteries are increasingly being used in digital cameras. They last twice as long as NiMH batteries of equal size and don't lose their charge as quickly while in storage. They also have a predictable voltage curve which allows cameras to have a reliable "fuel gauge" indicating how much charge is remaining. They can be charged and discharged as many times as NiMH batteries but normally become unusable after 2-3 years. The problem is that they are not available in as wide a range of models. This means that you won't have much choice when it comes to buying extra batteries or faster battery chargers. 

Most cameras come with their own batteries, but you'll find that one is never enough. You should have at least two so you can shoot with one while recharging the other.

Battery ratings

Batteries are rated by voltage and milliamp hours (mAH). Most AA-sized NiMH batteries are rated up to 2100 mAH. A 2100 mAH battery can deliver 2,100 milliamps (mA) for one hour (H). Generally speaking, the higher the rating, the more pictures you can take (all other factors being identical). How many you actually get depends on how energy efficient you are because the camera consumes energy between shots as well as when shooting. If you're careful, you might get about 100 shots per charge. However, if you use alkaline batteries, do lots of zooming and focusing, or leave the monitor on all the time, you might get only 25 or so.

 Battery chargers : Battery Chargers

There are so many battery chargers on the market it can be hard to choose among them. To help you, here are some guidelines. They range in price from about $8 for stripped-down models to $50 for fully-loaded models.

NiMH and/or NiCad? Most NiMH battery chargers can also handle NiCad cells. But the reverse is not always true. If you want to charge both types of batteries make sure the charger you get is designed for both. Don’t use a NiCad charger to charge NiMH batteries. It won’t necessarily damage them, but it won’t fully charge them either.

Many of the inexpensive NiMH battery chargers are simply NiCad chargers that have been modified slightly. Typically a 5 hour NiCad charger has a switch that allows the charge time to be increased from five hours to eight hours making it into an 8 hour NiMH charger. You might have to be careful when using this type of charger. While it is less expensive to manufacture than a smart charger, it can lead to overcharging and battery damage.

Size of cells Most digital cameras use AA size battery cells. However more and more cameras are starting to use proprietary battery sizes. If your camera uses something other than AA or AAA batteries you’ll need to buy a special charger designed specifically for your camera’s battery and your choices will be very limited and probably very expensive. If your camera uses LithiumIon batteries, you will need to use the batteries and battery charger provided by the manufacturer.

Number of cells Since it’s important to keep your batteries together in sets, you will want to choose a charger that can charge the same number of cells that your camera uses. Almost every AA battery charger can charge four cells at once. But if your camera uses only two or three cells, you should get a charger that also charges just two or three cells at a time. Even if your camera uses four cells at a time, you may decide to start using rechargeable batteries in your MP3 player. In that case, the ability to charge two or three cells might be useful.

Charge time How quickly a charger charges a set of batteries is probably the most important issue to most people. The speed of a charger also has the biggest impact on the price of the charger. Ignore labels such as "rapid charger" or "overnight charger" and find out how long it really takes a particular charger to charge a set of high capacity NiMH batteries. The fastest chargers on the market can charge 1600 mAh cells in about two hours. These chargers have a charge rate of about 800 mA.

It's fairly easy to estimate how long it will take a charger to charge your batteries. Simply divide the capacity of the battery by the charge rate of the charger, then increase the amount of time by about 20% to allow for a certain amount of inefficiency. As an example, a battery with a capacity of 1200 mAh will require about 6 hours to be fully charged by a charger with a charge rate of 250 mA. (1200 mAh/250 mA x120%). Incidentally this example is pretty typical for a standard AA NiMH battery and a typical "rapid charger." Keep in mind that a battery that is only partially discharged will be recharged in less time.

Some people wonder if rapid charging reduces the life of their batteries. It can, but it won't if the batteries and charger are designed for quick charging. With the right smart charger, most NiMH batteries can be recharged in as little as an hour without any damage or reduction in their life.

Battery chargers normally get power from an AC outlet. Some chargers plug directly into AC outlets. These plug in chargers have built-in AC to DC converters which provide the DC power necessary to charge the batteries. A plug in charger normally makes for the neatest solution. If you decide to buy a plug in charger, you may also want to look for one with a plug that folds into the charger when it’s not in use.

Many chargers require an external AC adapter known as a "power brick," that plugs into an AC outlet and connects to the charger with a thin power cord. Since the brick and cord adds to the clutter of your home or office, it’s something to consider. In addition to being unsightly, the power brick and cord can be a nuisance when you travel, adding still more clutter to the adapter and cable collection already required by your camera and PC. One advantage of chargers that use a the brick and cord type of adapter is that they often accept a "car cord" that plugs into a car cigarette lighter outlet.

Any battery charger that charges batteries at a reasonable fast rate, needs a way to stop the charge cycle when it’s complete so the batteries are not overcharged. The worst thing you can do to your batteries is overcharge them. The way to prevent this is to use a microprocessor controlled smart charger that monitors the battery charge and knows just the right charge for them. Avoid chargers that charge for a fixed length of time, regardless of what's needed. These 5 or 8 hour "rapid chargers" deliver the same charge to every set of batteries regardless of how much charge they actually need. Their only control is a simple on/off timer. These chargers cause problems in two ways:

• If you insert fully charged or partially charged batteries into the charger it has no way to sense this, so it gives the batteries the full charge it was designed to deliver. 

• If you interrupt the charge by pulling the plug and then plugging it back in, a complete charge cycle starts again, even if the previous charge cycle was almost complete.

The best way to avoid these scenarios is to use a smart charger with microprocessor control. The most sophisticated types of actually have separate circuits to monitor the charge level of each individual battery being charged. A smart charger can determine when a battery is fully charged and then depending on its design, either shut off entirely or switch to trickle charge. The point of the trickle charge is to keep the battery fully charged without overcharging it.

  LEDs and Audible Alerts. LEDs are standard on most chargers. They make it easy to tell when the charge cycle is complete or if the batteries haven't been inserted correctly. Audible alerts on some chargers are nice, but they certainly aren’t a must have. 

  Car cords. Some chargers that use an AC power brick also have an option to use a car cord.

A cigarette lighter adapter cable for use in the car.

  "Trickle" charge. All but the least expensive chargers now provide a trickle or pulse charge mode that maintains the batteries’ charge after the normal charge cycle is complete. Many battery manufacturers do not recommend trickle charging. To be safe, fully charge your batteries and store them in the freezer.

  Conditioning Circuit. Some smart chargers also have a "conditioning" circuit. This is basically just a discharge circuit, which discharges the batteries before it charges them. It can be useful to help prevent the voltage depletion effect that occurs in NiCad batteries, but it’s not too important for NiMH batteries. The only time it’s really useful for NiMH batteries is to quickly condition the cells when they are brand new. Since it takes a few charge/discharge cycles for NiMH batteries to reach their full capacity, a conditioning circuit makes it easy to run the batteries through a few cycles.

  Prolonging your charge

Once your batteries are charged, the goal is to keep them that way as long as possible. When you are out of battery power, you have to stop shooting. There are ways to prolong your battery's charge. 

 When you first get new rechargeable batteries, charge and discharge them a few times so they get fully charged.

 When photographing, turn off the power hungry LCD monitor and use the optical viewfinder. It's better for taking pictures anyway. When you have to use the LCD monitor, turn down its brightness, or use the black & white mode if it's available on your camera.

 If it's cold out, keep the camera or batteries under your coat to keep them warmer. Cold batteries deliver less power and die faster than warm batteries.

 If the camera is set to full-time autofocus, you'll hear the lens "hunting" for a focus point when you point the camera in different directions. To conserve power, switch full-time autofocus off so the camera only focuses when you press the shutter button halfway down.

 If using NiCad batteries, fully drain and recharge them periodically. The easiest way to do this is with a conditioning charger that drains the batteries before recharging them, or a pulse charger that uses a negative pulse to remove the gas bubbles that build up on the cell plates.

 Occasionally clean the battery contacts in the camera and charger with a cotton swab and rubbing alcohol (isopropyl alcohol). Most charging problems are caused by dirty contacts on the battery or charger.

 When not using the camera for an extended period, remove the batteries and store them in a cool, dry place. (Also remove flash memory cards from the camera when not in use.) 

 NiMH and NiCad batteries start to lose a few percentage points of power a day when stored at room temperature. But they will retain a 90% charge for several months if you keep them in the freezer after they are fully charged. When freezing them, put them in tightly sealed bags so they stay dry and also let them return to room temperature in the same bag before using them.

 When using the camera to display, print, or download images, use an AC adapter so the batteries aren't being drained.

Batteries don't last forever. Depending on their type, they'll last between 400-700 recharge cycles. For heavy users that's about 1 to 2 years. Generally, you can tell they are failing when they no longer hold as long a charge.

There's nothing more disappointing than having your batteries die just when there are important photos to be taken. The only way to prevent this is to have spare battery sets with you at all times.

Some photographers keep a set of AA Lithium batteries in a wallet as a permanent backup. Not only do they have three times the capacity of alkaline batteries, they have a shelf life of 10 years!

At home it's easy to misplace your batteries. Letting them just roll around on the counter isn't the ideal solution. It's easy to mix up the sets and it can be dangerous if the batteries short out on each other. To keep them organized, you need a desktop battery caddy.  When charged, put batteries in the caddy right side up. When dead, insert them right side down.

To boost your available power, you can look into external battery packs that plug into the camera's AC adapter. These devices are available but don't work with all cameras. be sure to check the manufacturers compatibility list.

When flying, be sure your batteries are charged. You may be asked to turn the camera on at a security check point. Also, be sure you can recharge your batteries. In the US, the power system is 120 volts and 60Hz. Overseas it's 220 or 240 volts and 50Hz. On top of this, there is a wide variety of wall plugs. To plug in battery chargers, AC adapters, and notebook computers, you need an adapter kit: preferably a universal plug and voltage adapter.

• An adapter is used to plug a dual voltage appliance, converter, or transformer into a wall outlet that doesn't match the device.
• A converter is used with electric appliances such as hairdryers.
• A transformer is used with electronic devices such as computers.

Converters can harm appliances over time and shouldn't be used for more than a few hours at a time. Transformers can be used for longer periods. The only problem with transformers is that they are much heavier than converters. 

  Recycling batteries

Many kinds of batteries, like those used in digital cameras, can be recycled instead of thrown away. When they wear out, try to take them back to the store where you bought them. Many stores collect the used batteries and then send them to a factory to be recycled. NiCad batteries use Cadmium, a highly toxic heavy metal, that can damage the environment if not disposed of properly. NiMH (Nickel Metal Hydride) batteries are the most environmentally friendly batteries because they are made from non-toxic metals.