Sony PCG-FXA59 User Manual page 26

To remove the second battery pack
If you attach two battery packs, you can remove either of them without shutting down the notebook. When removing one
battery pack, make sure that the other battery pack's indicator is on. If the indicator of the battery pack you are removing is
on, right-click the battery icon on the taskbar and click the "Switch discharge battery" option.
1.
There is a Release lever on the bottom of the weight saver. To remove the battery pack, slide this lever in the
direction of arrow 1, and then slide the RELEASE lever on the bottom of the notebook in the direction of arrow 2.
Multipurpose bay Release levers
2. Remove the weight saver, and then pull out the battery pack.
3. Reinsert the weight saver. See Using the Weight Saver for more information.
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