Here's a tip that might be helpful in reducing the drain on your iPhone battery. In looking at the battery usage over the past 24 hours on my iPhone I noticed 74% of the drain was coming from the cellular app. Why's this, I wondered? Then it dawned on me.
We have AT&T cellular service, and there is virtually no signal at our house here in Scottsdale. We have to use wifi to make and receive phone calls. So the cellular app in my iPhone sits there all day searching for a signal from AT&T that it will never receive. This consumes battery power.
I turned the app off, checked battery draw a day later, and 'voila', the drain from that app had about disappeared. When we leave our house, I'll turn the app back on so we can receive and make phone calls when we're out and about.