Laptop battery not fully charging to 100%

[18carNASCAR]

I was looking at a HP laptop kart for a family owned business. So I don't know the specs of the laptop's. So there was a computer kart that help approx. 30 laptops at a time. None of them would charge over 80% on the initial charging process. So the never where even started other than to write and image on a disk of the system software. So one day we started them with the 80% charge and there was a Windows 7 Enterprise update that went on. After that the next time we started the computers they charged to 91% and now they wont go beyond that.

The only thing I know about those computers is that they are HP, have the extended life battery, and they run the OS Win7 Enterprise

Any help to get the issue resolved would be greatly appreciated

Note that the all 30 laptops have only been started a minimum of twice through there whole life, and the were bought fresh for the company this year (2011)

[Salmon Trout]

The battery on some notebook computers may not indicate a 100% charge in Windows, even when the power adapter is plugged in. The battery may appear to stop charging between 95 percent and 99 percent.

This is normal operation and is designed to extend the life of the battery. Even when the indicator light on the chassis shows the battery fully charged, the battery still receives a trickle charge. The battery stops fully charging and is given a trickle charge so that it does not accidentally get overcharged.

To check battery status, press the battery meter button on each battery. If the battery status does not show 100%, the battery may need to be recalibrated. To locate the instructions for recalibrating a battery, consult relevant notebook documentation.

[Rob Pomeroy]

To locate the instructions for recalibrating a battery, consult relevant notebook documentation.

Agreed - in most cases though that amounts to discharging the battery fully and recharging.  I tend to boot to a BIOS screen, unplug the power and let it run until the battery's exhausted, then recharge again in the BIOS screen.  With some older-tech batteries, you need to do this a couple of times.