There is a myth that if you take
your battery out of
the laptop while you have it plugged into AC with the adapter for long periods
of time it will last longer. Sorry not true, I will explain further down the
page.
There is another myth that if you take the battery out when plugged into AC
for long periods of time and then put it back in once a month for a recharge it
will last longer. Sorry not true either.
The truth is that once the battery is charged it will began to degrade, that
is to say that after the initial charge the battery will never charge to it's
full potential again. Most manufactures will tell you this if you read their
product information. When you buy a battery and the manufacture says it will
last x hours the manufacture is giving you a ball park figure. The battery at
first will last longer by fifteen to thirty minutes, then slowly drop down until
you decide to buy a new one.
I have a IBM T30 that I use on a everyday basis, the battery when brand new
would last almost 3 hours. I know it lasted that long I took it on a overseas
flight to the UK when the battery was brand new and played some games on it
until the battery died.
To understand why your battery will degrade after the initial charge you have
to understand how the battery is made and how it is charged.
The battery that you take out of the laptop is really a pack of smaller
batteries in a plastic case. Depending on the manufacture there can be anywhere
from six to twelve or more batteries in the pack. Each battery is a 1.5 volt
Li-Ion or Ni Cad battery. The better type of battery is Li-Ion. If you look at the
battery pack it will say something to the effect that the pack will supply x
volts at x AH (Ampere Hours). If you want to know how many batteries are in the pack
divide the x number by 1.5 and you will get the total.
On newer laptops the charger is built into the laptop, it is part of the
power supply. The
charger will do what is called a trickle charge, it does not apply a lot of
voltage and amperage to the battery, just a small amount. In the battery pack
there is a small board that controls how fast the battery is charged and
discharged, this makes the battery last longer.
The myths:
When you discharge a Li-Ion or Ni Cad battery you do not completely discharge the
battery, it takes a special device to discharge these batteries, called a
zapper. So think of your battery as a glass of milk, you drink part of the milk,
you can see a ring where the glass was full down to where you stopped drinking,
a milk ring, after you are done with the glass of milk depending on how many
times you sipped out of the glass you will see some milk rings. Now lets use
this analogy and say instead of sipping the milk it is the length and number of
times you have powered up you laptop and then recharged the battery. If you do
not let the battery discharge completely - to the low battery warning beep - when
you plug it into to AC the battery will start charging at that point. The first
milk ring. This phoneme is called battery memory, each time you use the laptop
on battery and then plug it in to AC power it builds up memory until the length
of time the battery will last gets shorter and shorter.
The next myth is if you keep the battery out of the computer and recharge it
once a month. This will cause the battery to build memory faster. The battery
will have a charge already. If you do not discharge the battery to it's lowest
potential before you recharge it the memory build up will start where the
battery was discharged to. In other words the battery will over time discharge
by it self. If you charge your battery then take it out the laptop for a month
and don't complete the discharge the memory build up will start where the
battery has a charge at.
If you have a laptop and know you are going to use it on AC for most of its
life ( like my T30, it is my primary business computer) then discharging the
battery as far as it will go then removing it before plugging the laptop in to
AC will extend the life of the battery. You will just have to remember to charge
the battery before you head out with the laptop,
We just have to live with the fact that a laptop battery will only last for a
certain length of time then buy a new one and try to not let the new one build
up memory.
One last word of caution,
one of my friends pointed out to me that his battery would not hold a charge and
it is still in the laptop. This is not a good idea because it could over heat
and short out, if it did not cause a fire it surly will damage the computer and
the power supply. Another thing to consider about laptops being used as a
desktop for long periods of time is that once the battery reaches it's full
charge then the power supply has to do a trickle charge while it is installed.
My recommendation:
discharge the battery to its lowest point then remove it and store it until
you are going to use the laptop on battery only then charge it. Now this is not
a very good plan for those 'power out' emergencies which no one can predict but
it will save the battery and the power it takes to keep it charged.
Battery Life expectancy chart:
A new battery will recharge to 100%, as the battery ages the charge capacity
decreases. This chart is from my experience with laptop
batteries and is not a scientific study. Using the guide above
you can beat the average a little bit but in the end after a year of continuous
use you will need a new battery.
If you want to extend your laptop battery's usage consider putting a SSD
in place of the mechanical hard drive. I replaced the battery in my older T-30
Laptop recently. I also did an experiment to test the idea that using a SSD
would extend the time a Li-Ion battery would last. That is using a brand new
battery fully charged with a mechanical hard drive vs a SSD.
The new battery with a mechanical hard drive lasted one hour and twenty-two
minutes. To insure I was getting a quality test I repeated the test three times
and that was the average after each recharge of the battery.
With the SSD installed I am getting a constant 2 hours and seven minutes of
life from the new battery. I have been testing this everyday for the last two
weeks, once a day, giving the battery a full over night charge. I am very
pleased. Even brand new from the OEM the T-30's battery would only last an hour
and a half max.
Another benefit of using the SSD in your laptop is the reduction of heat
under the drive bay. The old hard drive would get very hot, almost to the point
that if I had to use the laptop on my lap I had to put something between the
laptop and my leg it was that uncomfortable.
If you would like to test your battery here is a procedure I have written to
assist you -
Laptop Battery stress tests.
This site contains a lot of information. As
with any publication not all information is available due to space, time, or
subject constraints.
If you have a question that you did not find the answer
on this web site you a can
ask your question here and we will endeavor to get you the most up to date
answer possible!
the laptop while you have it plugged into AC with the adapter for long periods
of time it will last longer. Sorry not true, I will explain further down the
page.
capacity
decreases. This chart is from my experience with laptop
batteries and is not a scientific study. Using the guide above
you can beat the average a little bit but in the end after a year of continuous
use you will need a new battery.
$67.00