Laptop Battery Replacement.

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 EU 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, 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. Miamicomputerrepairsite recommendation is 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.