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Old 10-16-2008, 09:09 AM
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Re: Battery

Quote:
Originally Posted by TurboFool View Post
Constantly draining them fully WILL cut down on their lives. But if you can help it, you also don't want to constantly charge them over and over again. They have a limited number of charge cycles (usually around 500) before they start to lose life. So plugging it in and unplugging it over and over throughout the day cuts into this heavily. That's hard, though, when even syncing the phone charges it, and when the battery life is as bad as it is on these models.
Actually Li-Ion batteries have circuitry built in to them the protects the battery from discharging too far (if the open cell voltage drops below 2.5 - 3 V the battery will be irreparably damaged).

Li-Ion Batteries also loose 20% capacity per year just sitting around at room temperature so don't buy extra batteries unless your going to use them. This can be decreased by storing at 40-60% charge (or putting them in the freezer) Also after charging, Li-Ion batteries loose about 5% of their charge per month and it is even higher at elevated temperatures

The biggest killer of Li-Ion batteries is temperature, leave your battery in a hot car for a couple of hours and you could permanently decrease your capacity by 50%!

Which gets to charging, It is debatable whether it is better to charge in small increments or to discharge the battery and then recharge. The loss in capacity of the battery (i.e. usable life) is due to the effects of heat caused by charging. Are many smaller temperature excursions (charging cycles) better than fewer larger temperature excursion? The jury is still out on that so do what works best for your usage pattern, but if you notice that the battery gets hot (over 90 F) when charging after a deep discharge cycle, you might consider limiting how many times you do that.

To to minimize charging temperature excursions, I always buy an external charger, pop out the battery and charge outside of the device so that I don't have the thermal resistance of the case to deal with. (A good friend of mine charges his batteries in the freezer, gotta love engineers...)

Sorry for the long post, but there is so much speculation and misinformation out there about these beasts.....
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