Please be aware that not all battery types mentioned here will be suitable for your camera or other equipment, so always check your manual before purchasing.
The most commonly used battery types for cameras are as follows:
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.
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.
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.
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
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
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.
Batteries are a less important consideration in conventional film cameras, because they last for much longer without needing replacement. In digital cameras they can affect your buying decision. Althoughmany people would prefer to use standard types of batteries, such as AA's, most manufacturers develop their cameras around proprietary Li-ion batteries because of advantages listed earlier. Although in most cases they give very good performance they have the disadvantage of being expensive to replace or buy spares. So if you are thinking of purchasing a digital camera, consider these options, if you have a lot of AA rechargeables already, you might want to save money by buying an AA compatible camera. If however you want light, longer lasting power and are not to concerned about the expense, you should consider a camera using proprietary Li-ion batteries.
For an example of the differences in cost of ownership for these two types of battery, we looked at the Minolta Dimage 7 and the Sony DSC-F707. The Minolta uses 4xAA batteries, and is supplied with one set and a charger. The Sony uses their own Li-ion battery. Despite similarities in features, the difference in power use between the two cameras is substantial, with users reporting the Sony can last as long as three hours from one charge, yet Minolta users are quoting figures of only about an hour from each set of batteries. To achieve the same amount of camera usage as the Sony, a Minolta user would need to buy, charge and carry with them two more sets of high capacity NiMH batteries.
NiCd batteries can suffer from what is known as 'memory effect'. This is caused by the battery being only partially emptied of charge before being recharged. When it's next used it thinks it has less capacity than it does and causes reduced battery performance. NiMH batteries are not supposed to have this problem, but some people still insist they do.
Batteries should be properly conditioned before being used, this involves fully charging and discharging them for the first couple of cycles. It is therefore best to buy one of the more advanced chargers that can discharge the battery before charging it. This makes sure that no 'memory effect' can occur. The advanced chargers can also offer other useful features, like top-up charging where the batteries charge is kept high if they are left in the charger for a long time.
No battery should be left charging for longer than recommended by the manufacturer, unless the charger has advertised functionality to switch off when the proper charge has been achieved. If batteries are left charging after the recommended time, they power capacity may be reduced, they could even set on fire or explode.