Comment 1 for bug 668057

Thank you for taking the time to report this bug and helping to make BatteryStatus better.
This is really pretty nasty bug - I've checked it on Lucid Netbook Edition, so I can confirm the issue.
I think, that fix will be committed at next week, but if you can't wait, you can easy fix it manually - just open Terminal and run:

$ sudo sed -i 's/message_battery_status.set_property("deletable", False)/message_battery_status.set_property("deletable", True)/' /usr/lib/battery-status/battery-status

Re-login after that, and now status window should have close button. However, let me know, if it's work or doesn't.