2009.0 kde4.2.4 update: battery applet not showing

Today a kde4.2 update showed up in my wife's acer aspire one.
kde4powersave didn't work with the aao, so I used guidance-power-manager
instead.
Kde4.2 uses powerdevil instead of kde4powersave, so I tried to uninstall
guidance-power-manager and install plasma-krunner-powerdevil.
Powerdevil seems to work as configured in the kde control panel, but I
cannot add a battery applet, since it doesn't appear in the list of
applets to add (there are other applet installed that don't appear there).
I'm kinda puzzled since I have another laptop where the battery applet
is there, however that was already using kde from the kde repositories
(also updated today to the "official" 4.2.4) and I never used
guidance-power-manager there.

Any hint on why the applet doesn't show?

TIA
--
Luca