By Steve Palmer
Rechargeable batteries for digital cameras need to have both a high level of voltage and the ability to maintain charge over long periods, due to the requirements of the device. Many contemporary models include both a flash and film-making capability, which are excellent features, but take a heavy toll on battery power, draining it at twice the rate of a camera used for only photos.
The idea of rechargeable batteries is not a new one, but finding the right one for a digital camera requires a few special considerations, including the material of the battery, the speed at which it charges, and how long it will endure both when the camera is in use and also during periods of inactivity.
When looking to buy a new digital camera it may be helpful to choose one with a common, easily replaceable, battery model. However organised you are, you may find yourself in a situation where the camera's battery power has run out and you need replacements at short notice, especially if you are a professional photographer on a shoot. Therefore it's useful to have a model which can take old-fashioned alkaline batteries in an emergency, even if rechargeable batteries are the ideal first choice.
Several things need to be taken into account when choosing which rechargeable battery is the best one for your camera: they include the amount of voltage in the battery, the primary concern, but also the duration of the battery's life in use, and additionally how long it will retain charge when not actively in use.
The following is a list of common rechargeable batteries along with their voltage output.
Ni-Cad rechargeable batteries - 1.2 volts
Ni-MH rechargeable batteries - 1.2 and 1.5
Ni-ZN rechargeable batteries - 1.6 volts
Standard alkaline batteries are 1.5 volts
mAh (milli Amp hours) is a rating which refers to the level of stored energy capacity within a battery; the range of mAh is typically between 750mAh and 2100 mAh, the higher number denoting a greater amount of stored energy capacity, the higher the better.
The most commonly used brands of rechargeable batteries are the Ni-Cad and Ni-MH, both available in a range of different versions. The Ni-ZN is the new brand leader, with an extended shelf-life and high storage capacity. While rechargeable batteries can be charged up repeatedly, it is less well known that users experience diminishing returns after a certain number of recharges, with batteries taking in less charge over time, as chemical barriers build up internally to block charge.
This can be a real problem; rechargeable batteries which when new can support, say, 100 photos per charge, will become less long-lasting at the number of recharges increases, and allow less photos to be taken in the same amount of time. Some users start to experience diminishing returns after only 25-30 recharges. Nevertheless, compared to the cost of AA alkaline batteries, that is still good value, the rechargeable battery costing between $2.50-$5 depending on mAh, and the AA around $1.15.
Ni-ZN, the new and superior rechargeable models, are around $5 each, and last over 500 recharges before they start to degenerate, according to their manufacturers. Furthermore, they provide a higher voltage, and a flash, for instance, will recycle twice as quickly as it would with alkaline batteries. Compared to traditional batteries, and rechargeable competitors, the Ni-ZN have a significantly longer storage life and take a higher number of photos before running out of juice, at least 175 compared to 100 in the same amount of time with alkaline batteries.
The recycling of flash can be important, especially when taking photos indoors, when it can be frustrating to wait as long as two minutes for the flash to return to full power; furthermore, it is extremely frustrating to run out of battery in the middle of shooting a series of short videos.
Taking all factors into account, both in terms of costing and features, if the highest priced Ni-ZN batteries can indeed be recharged up to 500 times, they work out cheapest in the long term. They're clearly the best option out there if the claims of their manufacturers bear scrutiny, providing both a higher level of voltage, greater number of charges, and longer shelf life than competitors.
Steve writes articles about batteries and digital camera batteries for Battery Force.
Source:www.isnare.com |
