One of the things we take for granted in our high-tech world is batteries. As we become more and more “wireless,” our dependence upon batteries increases, because so much of our personal and office equipment runs on battery power: PDAs, cell phones, pagers, clocks, wireless microphones, etc. Batteries give us convenience in our jobs and lives, but batteries can be expensive, so it's important to understand a few basics.
There are two major types of batteries: primary and secondary. Primary batteries are used once and thrown away. These include alkaline, lithium, zinc air, and silver oxide. Secondary (rechargeable) batteries are made of nickel-metal hydride, nickel cadmium, lithium ion, and sealed lead acid. Here is a summary:
This most popular type of battery is used in a wide variety of devices (radios, flashlights, PDAs, toys, tape recorders). An alkaline battery has a shelf life of five to seven years and has a “sloping discharge,” which means it discharges gradually and becomes weaker. Alkaline batteries are popular for high-drain applications, such as digital cameras.
Ni-Cad (or nickel-cadmium)
These are more powerful than alkaline batteries, and used to be popular — although they are becoming less so — for cordless phones and other moderate-drain devices. The rechargeable ones have a “memory effect,” and unless they are discharged completely, will operate for shorter and shorter times.
This type of battery lasts the longest in high-drain devices. Lithium batteries work well at lower temperatures and have a shelf life of up to 10 years. They are the best nonrechargeable power source for high-drain and frequent-usage devices. They have a “flat discharge,” which means that they maintain the same level of power until they abruptly cease functioning. Lithium-ion (rechargeable) batteries are preferred for laptops.
These are the most cost-effective batteries for frequently used, high-drain devices. Nickel-metal hydride batteries can be recharged up to 1,000 times. On the down side, they have a limited shelf life and can lose 1 percent of their power per day.
Ken Pickle, CPCU, CMP, is manager, incentives and conferences, for Safeco Insurance Cos., Seattle.
Battery Care and Feeding
When replacing batteries, use a clean, rough cloth or a clean pencil eraser and gently rub the contact surfaces of the battery and the battery compartment. This will remove any buildup or debris.
If a piece of equipment will not be used for several months, remove the batteries.
Always replace all the batteries in a device at the same time.
Use the batteries recommended by the manufacturer, and don't mix types.
Store batteries in a cool, dry place at normal room temperatures.
Do not carry loose batteries in your pockets. You can be attacked by “hot pocket.” (Keys or other metal objects can make connection with the terminals and heat up.)
Use a high-quality battery charger, one that will turn itself off when the battery is fully charged. (Overcharging is the most common cause of early battery failure.)
Don't leave the battery charger plugged in when you're not charging batteries. The unit will continue to use power.
When using rechargeable batteries, keep them together as a set. Have more than one set, and use and recharge each set as a unit.