Quoting Neal Becker <ndbecker2(a)gmail.com>:
I've seen this once before- and now it's back. Battery
monitor is showing 2
icons in panel.
I thought maybe there were 2 instances, so I deleted one, and both icons
disappeared. Adding back battery widget, I've got 2 icons again.
I've seen an instance of this problem too quite recently. I've found
an explanation for this, however I didn't investigate any further.
I booted the laptop with the small battery. During boot-up I decided
to switch to the big battery, so I switched batteries. When I fired up
kde: the battery plasmoid thinks I have two batteries WTF?
Google told me that other people had a similar problem but in their
case the second battery was a real one from a wireless mouse. In this
case lshal showed the second (mouse) battery. HAL is where the
plasmoid gets the battery info from.
So I checked with lshal, and sure enough, it showed two batteries.
IIRC the output of lshal suggested that hal still knew that the
batteries were different, but still it was showing the same percentage
for both the batteries. Once I get home I'll try again to reproduce
the problem. Maybe it's a problem in HAL (or HAL + laptop oddities)
and not in the battery plasmoid.
Maybe you can check what lshal reports on your machine and if it makes
any sense at all?