Why CONFIG_ACPI_BATTERY has disappeared in 2.6.24-rc1

Today I have compiled 2.6.24-rc1 (from wireless-2.6 git) for testing the ath5k driver. Well, ath5k does not work as expected, but that's not the topic of this post.
After Thomas 'tglx' Gleixner has said me, the his hrt patches are no longer needed with 2.6.24-rc1, I wanted to check that with powertop.
During the check, powertop complained about CONFIG_ACPI_BATTERY not being set, and I was like "WTF o_O", because I used the .config of my 2.6.23 and just added the ath5k stuff to it.
The option really wasn't set, and I also could not find the switch in menuconfig, where it always has been.
After a small search and the help of ong from #powertop, I found the solution.
CONFIG_ACPI_BATTERY now depends on POWER_SUPPLY (it's Device Drivers -> Power supply class support), which was not enabled by default, and also was not enabled as a dependency of an enabled option...
Well, after enabling POWER_SUPPLY, ACPI_BATTERY was back again.