Latest update to kde version 4.7.1 broke upower and therefore battery applet stopped working.
Fix: update to upower 0.9.13 (or probably recompilation of upower might also help) fixes the problem and battery applet works again.
Well the most essential problem is that kde is not fully updated on cauldron, So maybe we can wait a little bit & finish the upgrade.
Here with the kde sc 4.7.1 full up to date (build in iurt of course), i do not have any problem with the battery applet.
Is it still valid ?
wally did upgrade upower to 0.9.13, but i was also not able to reproduce locally :/
After the update in the morning it is ok.