Battery life, how to use battery

Message

Sand · #1 Post by **Sand** » Wed Mar 23, 2005 5:26 pm

Hello,

Having a laptop less than a month, I'm not sure HOW to use the battery. They say it's good for about a year, but does that mean if you use it everyday, how much a day, how can they predict how long it will last if everyone's use is so variable?

I keep my notebook plugged in most of the day, but I don't know, is the battery still being worn down in some way even while the pc is plugged in? Because there are things that deteriorate used or not, such as batteries packaged in stores,film, etc.

Conversely, if I never used it, would it still have full power, or would it run down anyway, making it better to use it somewhat every day?It still says 100% on the taskbar. If it is always be charged back up and renewed when it is plugged into power, how does it then get used up in a year?

Also, if the computer is turned off and not plugged into a power source; is the battery brought into play at all? I'm asking this because I wanted to take the laptop with me on occasion, but would have to leave it in the car for some two hours or more before using. Would the battery be running down in this situation?

Are car battery chargers a good idea?

Thanks for your patience,
Sand

beerak · #2 Post by **beerak** » Wed Mar 23, 2005 6:50 pm

Sand wrote:Hello,

Having a laptop less than a month, I'm not sure HOW to use the battery. They say it's good for about a year, but does that mean if you use it everyday, how much a day, how can they predict how long it will last if everyone's use is so variable?

I keep my notebook plugged in most of the day, but I don't know, is the battery still being worn down in some way even while the pc is plugged in? Because there are things that deteriorate used or not, such as batteries packaged in stores,film, etc.

Conversely, if I never used it, would it still have full power, or would it run down anyway, making it better to use it somewhat every day?It still says 100% on the taskbar. If it is always be charged back up and renewed when it is plugged into power, how does it then get used up in a year?

Also, if the computer is turned off and not plugged into a power source; is the battery brought into play at all? I'm asking this because I wanted to take the laptop with me on occasion, but would have to leave it in the car for some two hours or more before using. Would the battery be running down in this situation?

Are car battery chargers a good idea?

Thanks for your patience,
Sand

Don't leave your laptop with battery inside your car. Sunny days can damage it irrecoverable.

Apx. life of li-ion is one year and then capacity is going down more quickly. 2 years old battery is still good one. More then 2 years ... who knows ...

But the worse thing you can do to your battery is not use it ... It sounds bad, but when you don't use li-ion battery it starts loosing capacity.

Charge it between 30-75% Never ever let it discharge to less then 4%

Sand · #3 Post by **Sand** » Wed Mar 23, 2005 9:20 pm

Beerak,

Thanks for those suggestions. I will not leave it in the car.

I think I know what you mean about not letting it get below 4%, but I don't understand about charging it between 30 and 75% . Do you mean to use it every day, but always keep it between those numbers?

Thanks,
Sand

jusa- · #4 Post by **jusa-** » Thu Mar 24, 2005 2:41 am

Hi!

I bought new IBM T40 laptop. My battery's full charge capacity is only 42,16 Wh and design capacity is 47.52 Wh. Cycle count is 1. Is this normal or should I ask new battery from IBM? Should I cycle the battery three times or is it bad to use it to 0%?

My laptop is manufactured in December 2004, but battery is manufactured in September 2003.

beerak · #5 Post by **beerak** » Thu Mar 24, 2005 6:13 am

Sand wrote:Beerak,

Thanks for those suggestions. I will not leave it in the car.

I think I know what you mean about not letting it get below 4%, but I don't understand about charging it between 30 and 75% . Do you mean to use it every day, but always keep it between those numbers?

Thanks,
Sand

In fact it is not a battery but a battery pack containing piles. When you use the battery odd piles are discharged continuously = one by one. When you discharge your battery less then critical. The first pile is discharged to zero capacity. When you charge it there will occur negative voltage and this pile will be lost forever. That's why it is not good to discharge it under apx. 4%

But reversely you will get better efficiency when you will charge li-ion when it has 30-75% for the same reason. But no worries use is as common, but don't discharge it too much and feel free to charge it when it is between 30-75.

beerak · #6 Post by **beerak** » Thu Mar 24, 2005 6:14 am

jusa- wrote:Hi!

I bought new IBM T40 laptop. My battery's full charge capacity is only 42,16 Wh and design capacity is 47.52 Wh. Cycle count is 1. Is this normal or should I ask new battery from IBM? Should I cycle the battery three times or is it bad to use it to 0%?

My laptop is manufactured in December 2004, but battery is manufactured in September 2003.

Yes you should return it. The warranty is running since the date of purchuase. It is not normal, 1 cycle and so quick decrease of the capacity.

Sand · #7 Post by **Sand** » Thu Mar 24, 2005 5:44 pm

I'm sorry, I appreciate that you're trying to help me, but my computerese is not that good, and since I've never had a battery till now, these terms you use concerning the battery i.e. deep discharge, full charge, deep cycled, reconditioning, I am not familiar with the language, so could never know how to apply them.

I mean, does re-charge mean simply to plug in the power cord after the battery gets low?

Is there an IBM site that teaches battery languageand functions?

Also, someone mentioned when their battery was manufactured, and the full charge capacity. Where would I find this information?

Thanks again,
Sand

dvorak · #8 Post by **dvorak** » Thu Mar 24, 2005 6:07 pm

Sand wrote:I'm sorry, I appreciate that you're trying to help me, but my computerese is not that good, and since I've never had a battery till now, these terms you use concerning the battery i.e. deep discharge, full charge, deep cycled, reconditioning, I am not familiar with the language, so could never know how to apply them.

I mean, does re-charge mean simply to plug in the power cord after the battery gets low?

Is there an IBM site that teaches battery languageand functions?

Also, someone mentioned when their battery was manufactured, and the full charge capacity. Where would I find this information?

Thanks again,
Sand

Alot of information about batteries and terms available at Battery University: http://batteryuniversity.com/index.htm

Battery info is available when you click on the green bar that displays the battery status on your taskbar and then choose Battery Information.