The battery leader for laptop batteries

Laptop Batteries and More Battery Products.

Laptop-Batteries :
The Biggest selection of notebook batteries, laptop batteries, and rechargeable batteries.

Sony Batteries

Laptop Parts

Compaq Parts

Dell Batteries

Search for your Laptop Battery

Laptop Hard Drives

Laptop Battery Information

CHARGING INFORMATION

Battery manufacturers recommend to slow charge a new NI-CAD battery for 24 hours before use. This initial trickle charge helps to redistribute the electrolyte to remedy dry spots on the separator that may appear when the electrolyte gravitates to the bottom of the cell during long storage. A slow charge also helps to bring all the individual cells within a battery pack up to an equal charge level because each cell may have self-discharged to different capacity levels during storage.

REFRESH INFORMATION

Commonly recommended way to get the maximum performance from your laptop battery. Refresh is the process of allowing your computer battery to drain completely (to do this you will need to disable all power management utilities). Once drained recharge the battery to 100% this will refresh all cells within the battery. Doing this every few months will help extend the life of your portable computer battery

DISCHARGE INFORMATION

The commonly used end-of-discharge voltage for the NI-CAD and Ni-MH is one volt per cell. At that voltage level, most of the energy is spent and the voltage starts to drop rapidly. Discharging a battery further could damage the battery through cell reversal. Caution should be exercised when discharging a battery too deeply under heavy load.

The end-of-discharge voltage of the Li-ion needs to be carefully controlled and must, under no circumstances, go below 2.5V per cell. Protection circuit intrinsic to the Li-ion pack prevent the battery from being discharged below the safe limit. If allowed to self-discharge below 2.5V, unrecoverable capacity loss occurs when stored in that condition for three months or longer. Similar to the Ni-MH and SLA, more cycles can be obtained by partially, rather than fully discharging the Li-ion battery.

The SLA should not be discharged beyond 1.75V per cell, nor can it be stored in a discharged state. The cells of a discharged SLA sulfate, a condition that renders the battery useless if left in that state for a few days.

Laptop Battery Types

There are thee main categories of computer batteries:

The first type of battery is the backup battery which can commonly be referred to as the CMOS battery. This battery is what holds your computers computer settings such as the time on date. This allows your computer to remember your settings which allows you not to have to enter the CMOS settings each time you turn on your computer.

The second type of battery is the bridge battery. This battery is only found within portable computers and is used as a temporarily backup for the main battery. This allows you to remove the main battery and replace it with a good battery without having to turn off the computer.

The third type of battery is the main battery. The main battery is also only found within portable computers and is used as an alternate source of power for portable use. This allows you to use the computer without having a direct power source.

LI-ON BATTERIES

(Lithium Ion) fragile technology requiring protector circuit, the Li-ion is used where very high energy density is needed and cost is secondary.

NI-CAD BATTERIES

(Nickel Cadmium) is a well known and understood battery the NI-CAD is used where long life, high discharge rate and economical price are important.

LI-POLYMER

(Lithium Polymer) a potentially lower cost version of the Li-ion under development and has not yet been released to the public.

NI-MH BATTERIES

(Nickel -Metal Hydride) provides incremental improvements in capacity over the NICAD at the expense of reduced cycle life and lower load current.

SLA

(Sealed Lead Acid) most economical for larger power applications where weight is of lesser concern

Additional Information on Li-Ion Laptop Batteries

Pioneering work for the lithium battery began in 1912 by G. N. Lewis but it was not until the early 1970’s that the first non-rechargeable lithium batteries became commercially available. Attempts to develop rechargeable lithium batteries followed in the eighties, but failed due to safety concerns.

Lithium is the lightest of all metals, has the greatest electrochemical potential and provides the largest energy content. Rechargeable batteries using lithium metal as an electrode are capable of providing both high voltage and excellent capacity, resulting in an extraordinary energy density.

After much research during the eighties, it was found that occasional shorts from lithium dendrites could cause thermal run-away. The cell temperature quickly approaches the melting temperature of lithium which results in violent reactions. A large quantity of rechargeable lithium batteries sent to Japan had to be recalled in 1991 after a battery in a cellular phone exploded and inflicted burns to a man’s face.

Because of the inherent instability of lithium metal, especially during charging, research shifted to a non-metallic lithium battery using lithium ions from chemicals such as Lithium-Cobalt Dioxide (LiCoO2 ). Although slightly lower in energy density than with lithium metal, the Li-ion is safe, provided certain precautions are met when charging and discharging. In 1991, Sony commercialized the Li-ion and is presently the largest supplier of this type of battery.

Distinct advantages of today’s Li-ion batteries are:

The energy density of the Li-ion is at least twice that of the NICAD and its load current rating is reasonably high. In fact, the Li-ion behaves similarly to the NICAD in terms of discharge characteristics. In addition, the Li-ion has a relatively low self-discharge.

No memory effect

500 to 800 charging cycles

Negative attributes of today's NiMH batteries are:

Susceptible to damage from overcharge and over discharge.

Charging: Only use battery chargers especially designed for the Li-ion battery.

Caution: Li-ion batteries have a very high energy density. Exercise precaution when handling and testing. Do not short circuit, overcharge, crush, mutilate, nail penetrate, apply reverse polarity, expose to high temperature or disassemble. High case temperature resulting from abuse of the cell could cause physical injury. Never try to charge a non-rechargeable lithium battery! Attempting to charge these batteries can cause explosion and fire which spreads toxic material that can inflict injury and damage equipment.

Important: In case of rupture, leaking electrolyte or any other cause of skin or eye exposure to the electrolyte, immediately flush with water. If eye exposure, flush with water for 15 minutes and consult physician.

Source: www.computerhope.com