Cellular Phone Battery Technology
Wireless phones have come a long way from the bulky radiophones of yesteryear that one could hardly call portable. Today's wireless offerings often weigh less than 7 ounces and can be small enough to slip into a shirt pocket. These improvements in wireless phone size and weight are thanks in large part to advances in battery technology.
Let's take a look at the three battery technologies common to current cell phones.
Although newer high-performance phones have rendered it nearly obsolete, NiCad is still commonly used in many consumer electronics for its durability and low cost. Among its pros and cons:
Nickel-Metal Hydride (NiMH)
- Compatibility. Older phones are more likely to require NiCad. It generates relatively little heat, and many older phones cannot withstand the more heat-intensive NiMH or LiON batteries.
- Durability. It charges quickly and handles well under extreme temperatures.
- Shorter Lifecycle. It provides relatively less power per charge, so you must recharge it more often. You can usually recharge it over 700 times before reaching the end of its useful life.
- Memory Effect. If you recharge a NiCad battery before it has completely discharged (run out of energy), it will "forget" that it has all of that extra capacity. So it will only partially recharge, leaving you with a weaker battery.
The next battery generation to follow NiCad, NiMH costs more but offers several improvements:
- Longer Lifecycle. A NiMH battery will last around 25-30% longer on each charge than a NiCad of similar size. Life expectancy, in terms of recharge cycles, is comparable to NiCad.
- Lightweight. Lighter than NiCad, NiMH batteries can weigh under 3 ounces.
- Less Memory Effect. Although still a problem, it occurs to a much lesser extent than with NiCad. Read "Memory Effect" in the NiCad section for more details.
- No Toxic Materials. Like everything else, when a battery reaches the end of its useful life the disposed remains end up back in the environment. NiMH does not contain the kind of toxic materials found in some batteries, and is therefore far more environmentally friendly.
As the newest battery technology, LiON is both superior to and more expensive than NiMH. It has some major advantages:
- Even Longer Lifecycle. The newest Internet-ready phones use a lot of muscle and they need a battery that can get the job done. LiON lasts up to twice as long per charge as NiMH and lasts approximately 400 charges.
- Lightest. The latest ultra lightweight phones use LiON batteries which tend to weigh 30% less than NiMH.
- No Memory Effect. You can recharge it at any time, even if it has not fully discharged, without losing performance. As a precaution though, you may want to fully discharge and then recharge your LiON battery from time to time. When it comes to precision equipment, better safe than sorry.
- No Toxic Materials.
Like NiMH, LiON batteries are relatively environmentally friendly.