Camera Batteries and charging advice

Alkaline
These are widely available, being used in everything from household appliances to toys. They are not rechargeable and have to be replaced when drained of energy. If these batteries are left in a camera and the camera is not used for a long period of time, the charge can remain forup totwo years.

Typical uses: Compact cameras, SLR cameras with optional motordrive, flash units.

Nickel-Cadmium(NiCd)
NiCds are the cheapest type of rechargeable battery. They are available with different power capacities, measured in Milliamp-hours (mAh). This rating indicates the batteries overall charge storage capacity. Generally higher mAh ratings mean the battery will give a longer performance. Higher capacity batteries tend to be more expensive, but this extra capacity is worth paying for, especially on high-drain devices like digital cameras.

Unlike alkaline batteries the charge in these batteries slowly decreases if they are left unused for around a month. However, being rechargeable means you can top them up again, but be warned NiCds suffer from what is known as 'memory effect' where if you don't fully discharge the batteries before charging their capacity is reduced. Over time this makes them become gradually less powerful until they eventually become useless. There are chargers available that help prevent this problem by discharging the battery before commencing charging. These chargers are definitely worth the extra money as you will obtain better performance from your batteries.

Typical uses: Low power digital cameras, Compact cameras, SLR motordrives, Flash units.

Nickel-Metal Hydride (NiMH)
NiMH batteries are more expensive than NiCds, and use a different technology to provide their power, resulting in much higher output. They therefore last longer when being used, but also have the problem of draining over time if left unused. These batteries do not suffer the 'memory effect' like NiCds. For best performance you should still try and buy a 'smart' charger that can discharge the battery before charging it. Also try to buy batteries with the highest possible mAh rating.

Typical uses: High power digital cameras, SLR camera motordrives, Flash units.

Lithium
These batteries tend to be a lot more expensive than otheroptions here and they are not rechargeable. They do have some big advantages and their lifetime can be as long as 10 years if left in devices with low power drains. There arefour common sizes; the 6v2CR5 used in SLRs (pictured here); 6v CRP2P (squatter version used in compacts); 3v 123A used in compacts and small SLRs; the 3 volt CR2 (two are usually used in compacts) and an AA substitute for flashguns and similar. Most of the compact and SLR cameras made in the last decade take one of these types.

Typical uses: Compact cameras, SLR cameras, occasional use digital cameras.

Lithium-Ion
Not to be confused with standard Lithium batteries, these are rechargeable, and share the characteristics of standard lithium batteries of being light and having high power. Because of their low weight and high power they are perfectly suited to high drain devices such as Digital cameras, where weight is also an important consideration. Most camera manufacturers produce their own size batteries, whichcan make it more difficult to track down spare ones from your local stockist, who may be reluctant to stock every option.

Typical uses: Digital cameras

Battery packs
For people using digital cameras you might be able to use one of these external battery packs. These plug into your digital camera and will last much longer than the standard batteries you use. They generally use NiMH batteries so performance can be very high. However not all digital cameras can use these, so you need to check before buying.

Typical uses: Digital cameras

Button batteries
Before we had all the rechargeable and lithium batteries, most cameras that needed a power sourceused small round batteries called button cells. These are now only found in a few SLRs and some lightmeters. The batteriesranged between 1.35v and 1.5v and often had silver oxide or mercury content. The mercury options, PX625 and PX400, used in cameras such as Pentax and Yashica mechanical models, have been discontinued because of their environmental effects. Fortunately substitutes have been introduced by an American company called Wein and these are imported by the Lowepro distributor in the UK who you can call on 01902 864646 and please mention ePHOTOzine.

As cameras became moredependent on batteries they needed more power and two batteries where used. Then when Lithium arrived these two batteries werecombined to make a 3v version (shown above right). These offer much more power than the individual 1.5v silver oxides so last longer and are still used in cameras such as the Olympus OM-4ti and recently launched Nikon FM3A.