Batteries

“Marriage has no guarantees. If that's what you're looking for, go live with a car battery.” - Erma Bombeck (U.S.
humorist, 1927-1996)

If you’ve ever owned a laptop computer, you’ve discovered that the batteries don’t last very long. And the amount of charge they hold, the length of time they last, goes down over time. Is this caused by overcharging or undercharging? Is there anything you can do about it? For answers, Slate.com interviewed Isidor Buchmann, the CEO of Cadex Electronics, a Canadian company that makes battery-testing equipment. Buchman also runs Battery University, a website for battery enthusiasts and engineers.

Rule #1: No matter what you do, your battery will become more useless over time. One day it will no longer charge up and is officially ‘dead’. “It will die if you charge it too much. It will die if you charge it too little. You can pull the battery out of your camera, stuff it under your mattress, and come back for it in five years. Guess what? Your battery will be dead.”

Rule #2: You can prolong battery life.
The typical lifespan of a lithium-ion laptop battery is about 18 months to 2 years. But these batteries will last much longer if you avoid undercharging, overcharging, and heat. Temperatures inside a laptop can reach more than 110 degrees Fahrenheit, which is ruinous to a battery.

Buchmann recommends
- Charge the battery only when the laptop is turned off.
- When the laptop is on and plugged in, remove the battery avoid the heat.
- Don't charge beyond 100% nor let the charge drop to zero.
Keep the charge between 80% and 20%.

Yes these rules are a nuisance but supposedly they work. They also apply to rechargeable camera batteries, etc. Keep the batteries cool and charged between 80-20%.

Rule 3: If you won’t be using your lithium battery for a while, be sure to charge it to at least 40% before putting it away. The charge will fall naturally over time and you want to avoid hitting 0%. But wait you say, don’t some batteries work better when drained to 0%. Yes. Older nickel-cadmium batteries used in cordless phones, electric toothbrushes and other cheap electronics do have a memory charge effect that works best when allowed to drain to zero.

Rule 4: Don’t rely on the battery life meter. As a battery degrades over time, the meter becomes less and less accurate about the remaining charge.

Bottom Line
Rechargeable batteries are an example of cost over convenience. Is it worth the extra time pulling batteries out to prolong life and avoid buying replacements? Are they worth using at all?

My wife was really frustrated with her new digital camera. The new rechargeable batteries would die in no time at all, in just hours. Then a friend recommended using non-rechargeable batteries and carrying a spare set to replace them when they die. This worked wonderfully well. On a two week vacation with a thousand pictures taken, we changed the disposable batteries just once in the second week.