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A usable version is here
http://packages.debian.org/lenny/xfce4-battery-plugin
[xfce4-battery-plugin_0.5.0.orig.tar.gz]
[xfce4-battery-plugin_0.5.0-7.diff.gz] The patch is important !
1) place the patch outside xfce4-battery-plugin-0.5.0 and
'patch -p0 < xfce4-battery-plugin_0.5.0-7.diff'
2) go to the "patch directory" xfce4-battery-plugin-0.5.0/debian/patches/
and move all patches outside xfce4-battery-plugin-0.5.0
3) apply patches 02 05 06 07 08. Patch 07 must be edited :
line 1, 2, 345, 346 change xfce4-battery-plugin-0.5.0.orig
to xfce4-battery-plugin-0.5.0
4) move patch 03 inside the xfce4-battery-plugin-0.5.0/ and
apply it there.
Now you can configure and make.
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Good Luck !
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