Why does my laptop battery die quickly? Can laptop batteries be repaired?
I used to be able to unplug it from charging, and it would last almost 2
hours, now it lasts 10 minutes unplugged. What's wrong with it?
Answer1:
Most NI-MH batteries have a life span of three years. They are
supposed to be good for about 1000 charges, so if you charge it daily,
you get about 3 years life from them. There are a lot of
variables that can affect battery life but considering the age of the
battery, I would say that it is time that you got a new one. you may be
able to get one cheap on Ebay. you may find that you
can eek a bit more life out of it by switching off bluetooth and wifi
and not running anything graphically intensive.
Answer2:
Laptop batteries are prone to failure after 3 years. Some die sooner,
some later. The capacity of the battery declines over time no matter
what. Looks like yours is ready to be replaced.
Answer3:
As the computer gets older, the battery life usually goes downhill. You can go to the store, and buy a new battery.
Can laptop batteries be repaired?
Laptop
batteries differ from other types of batteries in that they
provide a relatively short service life and are expensive
to replace. In this article we look at the reasons why these
batteries do not last and examine the high replacement cost.
We also look into the possibilities of repairing them.
Most of today's laptop computers are powered with Lithium-ion
batteries.
Under good conditions, Lithium?ion provides 300 to 500 discharge/charge
cycles or 2 to 3 years of service from the time the battery
leaves the production line. The capacity loss occurs through
increased internal resistance caused by cell oxidation. Eventually
the resistance reaches a point where the battery can no longer
deliver the needed energy although the energy may still be
present in the battery. There are no remedies to restore the
capacity when worn out. Heating the battery will momentarily
improve the performance.
Figure 1 illustrates the recoverable capacity at various storage
temperatures and charge levels over one year. Nickel-based
chemistries, a chemistry that is also used in laptops, is
illustrated on the right column. The capacity loss progresses
on a quasi linear scale for the second and third year.
Figure
1: Non-recoverable capacity loss on Lithium-ion and nickel-based
batteries after one year of storage. High charge levels
and elevated temperatures hasten the capacity loss. The capacity
loss past one year progresses on a fairly linear scale.
During use, the battery compartment in many laptops rises to about 45°C (113°F). The combination of high charge level and elevated ambient temperature presents an unfavorable condition for the battery. This explains the rather short lifespan of laptop batteries.
Most laptops batteries are 'smart', meaning that some form of communications occurs between the battery and user. The definition of 'smart' varies among manufacturers and regulatory authorities. Some manufacturers call their batteries 'smart' by simply adding a chip that sets the charger to the correct charge algorithm. The Smart Battery System (SBS) forum states that a 'smart' battery must provide state-of-charge (SoC) indications.
There are two common architectures of 'smart' batteries. They consist of the single wire system found on high-end radio communications devices and video camera equipment, and the two-wire system, typically used on laptops. The two-wire system is usually configured as System Management Bus (SMBus). Because of its common use in laptops, we will focus on the SMBus system. Figure 2 shows the layout.
During use, the battery compartment in many laptops rises to about 45°C (113°F). The combination of high charge level and elevated ambient temperature presents an unfavorable condition for the battery. This explains the rather short lifespan of laptop batteries.
Most laptops batteries are 'smart', meaning that some form of communications occurs between the battery and user. The definition of 'smart' varies among manufacturers and regulatory authorities. Some manufacturers call their batteries 'smart' by simply adding a chip that sets the charger to the correct charge algorithm. The Smart Battery System (SBS) forum states that a 'smart' battery must provide state-of-charge (SoC) indications.
There are two common architectures of 'smart' batteries. They consist of the single wire system found on high-end radio communications devices and video camera equipment, and the two-wire system, typically used on laptops. The two-wire system is usually configured as System Management Bus (SMBus). Because of its common use in laptops, we will focus on the SMBus system. Figure 2 shows the layout.
 |
Figure 2: Two-wire SMBus system. The SMBus is based on a two-wire system using a standardized communications protocol. This system lends itself to standardized state-of-charge and state-of-health measurements. |
The SMBus battery has
five or more battery connections consisting of the positive
and negative battery terminals, thermistor, clock and data.
The connections are commonly not marked and attempting to
test this type of battery appears complicated. Figure 3 describes
the functions of a battery with 6 connections.
 |
Figure 3: Connections
of a typical laptop battery. The positive and negative
terminals are usually placed on the outside; no norm exists
on the arrangements of the contacts.
The positive and negative battery terminals are commonly located at the outer edges of the connector. The inner contacts accommodate the clock and data. (On a one-wire system, clock and date is combined.) For safety reasons, a separate thermistor wire is brought to the outside. This allows temperature protection if the digital communication is disabled.
Some batteries are equipped with a solid-state switch that is normally in the off position. In such as case, no voltage is present. Connecting the switch control terminal to ground will turn the battery on. If this does not work, a proprietary code may be needed to activate the battery.
How can I find the correct terminals? To begin with, use a voltmeter to find the positive and negative battery terminals. Establish the polarity. If no voltage is available, a solid-state switch may need to be activated. With the voltmeter connected on the outer terminals, take a 100-Ohm resistor (other values may also work). Connect one end of the resistor to ground, and with the other end touch each terminal while observing the voltmeter. If no voltage appears, the battery may be dead or the pack requires a digital code to activate. The resistor protects the battery against a possible electrical short.
Once the connection to the battery terminals is established, charging should be possible. If the charge current stops after 30 seconds, a digital code may be required. Some battery manufacturers go as far as to add a defined end-of-life switch. If a preset age, cycle count or capacity is surpassed, the battery stops functioning. When asking why such codes are added, the manufacturers explain that enduring safety can only be guaranteed if the battery is tamper-free and well performing. This makes common sense but the leading motive may be pricing. In the absence of competition, replacement batteries can be sold at a premium price. Newer batteries are generally more service friendly than older ones.
It is recommended to utilize the thermistor during charge and discharge to protect the battery against over heating. The thermistor can be measured with the Ohmmeter. The most common thermistors are the 10 Kilo Ohm NTC type, which read 10kOhm at 20°C (68°F). NTC stands for negative temperature coefficient, meaning that the resister decreases with rising temperature. A positive temperature coefficient (PCT) will increase the resistance. Warming the battery with your hand may be sufficient to detect a change in resistor value.
An SMBus battery contains permanent and temporary data. The permanent data is programmed into the battery at time of manufacturing and includes battery ID number, battery type, serial number, manufacturer's name, and date of manufacture. The temporary data is acquired during use and consists of cycle count, user pattern and maintenance requirements. Some of this information is renewed during the life of the battery.
The positive and negative battery terminals are commonly located at the outer edges of the connector. The inner contacts accommodate the clock and data. (On a one-wire system, clock and date is combined.) For safety reasons, a separate thermistor wire is brought to the outside. This allows temperature protection if the digital communication is disabled.
Some batteries are equipped with a solid-state switch that is normally in the off position. In such as case, no voltage is present. Connecting the switch control terminal to ground will turn the battery on. If this does not work, a proprietary code may be needed to activate the battery.
How can I find the correct terminals? To begin with, use a voltmeter to find the positive and negative battery terminals. Establish the polarity. If no voltage is available, a solid-state switch may need to be activated. With the voltmeter connected on the outer terminals, take a 100-Ohm resistor (other values may also work). Connect one end of the resistor to ground, and with the other end touch each terminal while observing the voltmeter. If no voltage appears, the battery may be dead or the pack requires a digital code to activate. The resistor protects the battery against a possible electrical short.
Once the connection to the battery terminals is established, charging should be possible. If the charge current stops after 30 seconds, a digital code may be required. Some battery manufacturers go as far as to add a defined end-of-life switch. If a preset age, cycle count or capacity is surpassed, the battery stops functioning. When asking why such codes are added, the manufacturers explain that enduring safety can only be guaranteed if the battery is tamper-free and well performing. This makes common sense but the leading motive may be pricing. In the absence of competition, replacement batteries can be sold at a premium price. Newer batteries are generally more service friendly than older ones.
It is recommended to utilize the thermistor during charge and discharge to protect the battery against over heating. The thermistor can be measured with the Ohmmeter. The most common thermistors are the 10 Kilo Ohm NTC type, which read 10kOhm at 20°C (68°F). NTC stands for negative temperature coefficient, meaning that the resister decreases with rising temperature. A positive temperature coefficient (PCT) will increase the resistance. Warming the battery with your hand may be sufficient to detect a change in resistor value.
An SMBus battery contains permanent and temporary data. The permanent data is programmed into the battery at time of manufacturing and includes battery ID number, battery type, serial number, manufacturer's name, and date of manufacture. The temporary data is acquired during use and consists of cycle count, user pattern and maintenance requirements. Some of this information is renewed during the life of the battery.
