Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3) Anybody know...
Enabling Siri doesn't use more battery, but using Siri uses more battery. Using an app requires the battery to drain a little, this goes for every app, not just Siri.
It actually does.. I noticed I get around a hour more battery life without siri. This is probably due to Siri audio processing daemon running in the background - it consumes some CPU cycles.
I have Siri turned on on my 4S, but I rarely use it. So far I have really good battery life. That daemon isn't active until Siri is used. Then when Siri is no longer in use, it kills itself.