Another option is in the advanced section of the WiFi settings where you can tell it to ignore weak wifi signals. This way, it won't keep trying to connect to a weak signal.
I myself have it set up so that Smartactions turns my wifi on when I'm at home and at work (wifi access at work). Otherwise, wifi is turned off (default) outside of those areas. Otherwise, if you are in an area that does not have wifi, it will keep searching for wifi which can drain your battery.
For me, I can go an entire day and a half without charging which is the same as it was under JB.
