windows xp dark screen

I have a Sony Vaio VGN FS52B running on Windows XP. When connected to electricity, the screen is very bright, but when running on battery, the screen is very dark. Sometimes when running on battery, the screen light starts shaking and blinking and may suddenly become bright. Please what can I do to solve this issue.
Also, when the system is connected to electricity, it runs smoothly but when running on battery, it frequently hangs. Please any solutions. Thanks.

 

My first guess would be a dying battery unless the battery contacts are dirty (possible leakage?). What is the battery charge level after plugging the computer back into the power grid?

Here is an article about battery life...

How to Check Your Laptop’s Battery Capacity​

The same article has a link to a battery utility that you can download to do an in-depth diagnostic with...

BatteryInfoView ​

 

@ James-> Thanks for the prompt reply. When the battery is between 60 -100%, when I close the lid and open it like 8 times continuosly , the screen becomes bright but below 60%, the screen remains dark. Also, the battery does not last up to 1hour when fully charged. My guess also has been the battery.

 

At James>


Description Value
Battery Name
Manufacture Name Sony Corp.
Serial Number
Manufacture Date
Power State Charging, AC Power
Current Capacity (in %) 30.8%
Current Capacity Value 15,959 mWh
Full Charged Capacity 51,784 mWh
Designed Capacity 51,784 mWh
Battery Wear Level 100.0%
Voltage
Charge/Discharge Rate
Chemistry Lithium Ion
Low Battery Capacity (1) 4,708 mWh
Low Battery Capacity (2) 11,769 mWh
Critical Bias
Number of charge/discharge cycles 0
Battery Temperature
Remaining battery time for the current activity (Estimated)
Full battery time for the current activity (Estimated)
Remaining time for charging the battery (Estimated) 02:06:42
Total time for charging the battery (Estimated) 03:02:50

 

@ James> I downloaded the Battery info software and installed. This is what the details are:
Description Value
Battery Name
Manufacture Name Sony Corp.
Serial Number
Manufacture Date
Power State Charging, AC Power
Current Capacity (in %) 30.8%
Current Capacity Value 15,959 mWh
Full Charged Capacity 51,784 mWh
Designed Capacity 51,784 mWh
Battery Wear Level 100.0%
Voltage
Charge/Discharge Rate
Chemistry Lithium Ion
Low Battery Capacity (1) 4,708 mWh
Low Battery Capacity (2) 11,769 mWh
Critical Bias
Number of charge/discharge cycles 0
Battery Temperature
Remaining battery time for the current activity (Estimated)
Full battery time for the current activity (Estimated)
Remaining time for charging the battery (Estimated) 02:06:42
Total time for charging the battery (Estimated) 03:02:50

What do you think the problem is. Thanks for your concerns.

 

Pete, could it be just the opposite?

Excerpt for BatteryInfoView...

Battery Wear Level: The wear level of the battery, in %
The wear level of a new battery should be around 100%, and it gradually decreases.​