If you use Laptop and Ubuntu, you can check whether your current battery status is in good condition of need a replacement. Just type this command in your shell:
Depending on your hadware config, you’ll see result like this :
present: yes design capacity: 6600 mAh last full capacity: 6600 mAh battery technology: rechargeable design voltage: 14800 mV design capacity warning: 660 mAh design capacity low: 198 mAh capacity granularity 1: 264 mAh capacity granularity 2: 3780 mAh model number: Primary serial number: battery type: Lion OEM info: Hewlett-Packard
If last full capacity is lower than design capacity than your battery is slowly going to it’s end.