E-Machines eMachines Desktop PC "replace 6 cell li ion" Questions

...6 cell)40Y831592P1184Sanyo 92P1186Sony Li-Ion battery (9 cell)40Y831792P1188Sanyo Here's an online store and also here. Or you can take your battery and go to a local store to ask for a replacement ...

...6-cell Li-ion battery. My problem is: last time my laptop lowered battery output - it means laptop charged battery till 50%, then 32%, then 25% and now 15%. Charging light on laptop is still orange ...