Types of Digital Camera Batteries
I mentioned in a previous post, About Digital Cameras, I mentioned that you should always buy two sets of rechargeable batteries. In this post I discuss the two most common rechargeable batteries used by digital cameras, although there are other types of rechargeable batteries on the market.
Nickel-Metal Hydride (NiMH)
Although research into the NiMH system began in the 1970s, these batteries first began being used commercially around 1990 and are currently used in digital cameras in AA form. In the early days of NiMH batteries, the metal hydride alloys were unstable so the desired performance characteristics were not achieved.
In the 1980s, new metal hydride alloys were developed that were stable enough for use in a cell. By the late 1980s, the energy density of the NiMH batteries had gradually improved.
The metals used in NiMH batteries are environmentally friendly and have a high energy density, which have contributed to its success.
The fast charge time of a battery is 2 to 4 hours. The charge-discharge cycle life of a NiMH battery is roughly 300-500 cycles at up to 80% of the initial capacity. If not used, a NiMH battery will lose 30% of its charge every 30 days.
Lithium Ion (Li-ion)
Early work with creating the lithium battery began in 1912 by G.N. Lewis. The first non-rechargeable lithium batteries became available in the early 1970s. The instability of the lithium metal during charging caused safety concerns during attempts to make a rechargeable lithium batter in the 1980s.
Lithium metal is a light-weight metal and has the greatest electrochemical potential and also provides the largest energy density per weight. Since lithium is unstable during charging, non-metallic lithium has since been research. Although lower in energy density than lithium metal, lithium ion is safe, provided that certain precautions are following during charging and discharging.
The first Li-ion battery was first commercialized by Sony in 1991.
It will take 2 to 4 hours to fully charge a Li-ion battery. The number of charge-discharge cycles for a Li-ion batter is 500 to 1000. The Li-ion battery will lose about 10% of its charge every 30 days.
The charge of a Li-ion battery will decrease over time because of oxidation. This occurs naturally and cannot be restored with cycling or any external method. The loss of charge capacity is permanent because the metal used in the cells is only designated to last for a certain period of time.
Which Battery Should I Use?
Many digital cameras include a large battery that can be charged within the camera itself. These batteries are usually the Li-ion type of rechargeable battery. They will usually last quite a long time when not in use, so you won’t need to recharge as frequently. The Li-ion batteries are usually more expensive to purchase, and your digital camera may only accept a specific model.
If your camera only accepts AA batteries, then you should choose the NiMH rechargeable batteries. These batteries may come with their own charge since you won’t be able to charge them right in the camera. Always buy two sets of batteries, so when one set has discharged, you can use your spare while recharging the first set.
Look at the milliamp hours (mAH) value when purchasing rechargeable batteries. This value is a measure of the battery’s total charge capacity. The higher the number means the larger the capacity.