We all use batteries – agreed?. Almost any equipment you buy today, be it Digital Camera, Video Camera, Mobile Phone, Laptop and like has invariably two types of power sources, AC and Battery (DC). Do we really use the batteries the right way so that its life is prolonged? Surely the rechargeable batteries are costly. The cost? I recently bought the Video Camera and had to get a spare battery since the one bundled with it was hardly going to do the job especially outdoors. The price of the battery only was a whooping 25% of the cost of the camera. I am referring to the high capacity battery as I also had the option to go for a lesser capacity at about 18% of the cost of camera. The point I am trying to make here is we all spend a lot of money on batteries these days and therefore there is a need to care for them.
One of the most comprehensive site is the Isidor Buchmann's site - Batteries in a Portable World
probably the most comprehensive site having to do anything and everything with rechargeable batteries.
Here are some of the excerpts from the site, which I hope you will find very useful and will help you prolong the life of the batteries you use in your laptops by observing his tips.
"A lithium-ion battery provides 300 to 500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery....
"Although lithium-ion is memory-free in terms of performance deterioration... short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this....
"...lithium-based batteries have a lifetime of two to three years. The clock starts ticking as soon as the battery comes off the manufacturing line....
"If possible, store the battery in a cool place at about a 40% state-of-charge. This reserve charge is needed to keep the battery and its protection circuit operational during prolonged storage. The most harmful combination is full charge at high temperature. This is the case when placing a cell phone or spare battery in a hot car. Running a laptop computer on the mains has a similar temperature problem. While the battery is kept fully charged, the inside temperature during operation rises to 45°C (113°F)."
"The Li-ion does not like prolonged storage. Irreversible capacity loss occurs after 6 to 12 months, especially if the battery is stored at full charge and at warm temperatures. It is often necessary to keep a battery fully charged as in the case of emergency response, public safety and defense. Running a laptop (or other portable device) continuously on an external power source with the battery engaged will have the same effect....
"The combination of a full charge condition and high temperature cannot always be avoided. Such is the case when keeping a spare battery in the car for a mobile phone. The NiMH and Li-ion chemistries are most severely affected by hot storage and operation. Among the Li-ion family, the cobalt has an advantage over the manganese (spinel) in terms of storage at elevated temperatures.
"The charge time of all Li-ion batteries, when charged at a 1C initial current, is about 3 hours. The battery remains cool during charge. Full charge is attained after the voltage has reached the upper voltage threshold and the current has dropped and leveled off at about 3 percent of the nominal charge current.
"The charge process of a Li-Polymer is similar to that of the Li-ion. Li-Polymer uses dry electrolyte and takes 3 to 5 hours to charge. Li-ion polymer with gelled electrolyte, on the other hand, is almost identical to that of Li-ion. In fact, the same charge algorithm can be applied. With most chargers, the user does not need to know whether the battery being charged is Li-ion or Li-ion polymer.
"Almost all commercial batteries sold under the so-called ‘Polymer’ category are a variety of the Li-ion polymer using some sort of gelled electrolyte. A low-cost dry polymer battery operating at ambient temperatures is still some years away."
For further reading you may visit the site Batteries In A Portable World
which also happens to be the title of the book written by Isidor Buchmann. The book in its entirety is available for reading online if you prefer, but, before you can do that, you need to register - which of course will cost you nothing!
paying my dues on this wonderful site for the knowledge I gained here from fellow members!