Yes, just leaving the phone on drains the battery, even if you don't use it. I use mine mostly for long distance calls since all the family are long distance from our town. In between calls, I just turn it off and everyone knows to call me on the land line.

The GPS function can increase the drain. Most of the time you do not need it and it can be turned off, but do select the mode that activates it when 911 is called. A number of emergency centers are equipped to locate your phone by its GPS data or by triangulation of 3 cell phone towers is enough towers happen tobe in range. This 'find' feature is critical if one makes a 911 call and is too incapacitated to give direction or does not know where they are at, e.g. can not supply enough information or address for locating.

If you have version 8 of the software, in set up there is a tool that tells you what % of usage each program is using. From Set up you go to General, then Usage and then Battery usage.

If you don't have the tool or aren't real familiar with your phone, you could take it to the apple store in your area to have one of the people there fix it. Do you have an apple store close by?

I agree with most of the other comments.

Phones that are turned on will continue to exchange "handshakes" with the cell system. Repeating the equivalent of "Are you there?"- "Yes I'm here" "Still there?" - "Yes, still here" kind of traffic, I want to say at least every minute or so. How much power that uses depends on signal strength and proximity to the tower. One couple we know lives in a valley of a hilly area that seems to have weakened reception for our cell carrier. A 4 hour visit to their house can suck 40-50% of my phone's charge with no use at all besides incoming emails. My guess is that happens because the signal strength is one bar and the phone needs to use stronger transmission power to keep in touch with the tower. I turn my phone off now when we go there.

Have you moved lately? Is the signal strength strong at the normal spot where you keep your phone?

I'll also add that phone batteries lose their prowess in getting and holding a charge as they age. Batteries stay strong with discharge/recharge exercise. If your usage pattern has been to discharge it slowly over as long as one week and only then recharge it, your battery may be running low on Popeye's spinach.

Is your phone still under a warranty? Your alternative maybe be between either replacing the battery (usually done by Apple, not a cheap repair) or replacing the phone if ultimately you find it can't hold a charge long enough to be useful for you .

Every phone has a built in program that shows what is using the battery and if you don't like that one there's lots more apps available for free that do it. You need one to determine what is using the battery. Turn screen brightness down as low as possible. Completely power off the phone every day or so in case it's something not releasing resources when shut off. Turn off the auto updates for any apps that are not essential. Start plugging in the charger nightly to see if the battery changes how it's behaving.

This is a sudden change in behavior I'm talking about, everything else equal. I do have an app that shows resource allocation and battery life but it hasn't said anything worth knowing about this.

I'll try plugging it in nightly and see if that helps. Maybe it'll relearn to how to hold a charge. :)

Thanks, everybody!

Anyone know if it could possibly be the charger cord? What about photos? Do you have a lot stored on the phone?

PKponder, Thanks for the link. My serial number isn't on the list, though it sounds like the same behavior...BUT I have a new theory. I'm wondering if it's my summer purse? It was an issue because I had to go to a trade show, but left the purse home. I've been using the phone and watching it closely, and it seems to be discharging at a steady pace. It's been on for two days and unplugged for longer, I've made a couple of calls, updated a few apps manually and did some data searches, which add up to 2.5 hrs. usage. It's hot out, though much of the time the phone has been in air conditioning. The monitor says it has 55% charge left.

That's not as long a charge as when it was new, of course, but acceptable, normal behavior. Not losing its charge from just off the charger to not even a trickle during daylight hours, which is what it had done. Do you think a magnetic pocket mirror which is separated by several layers of cloth and a couple more of leather could be strong enough to drain it? I had the same things (purse, phone, phone case, mirror) last year, but did just find the mirror on the same side as the phone pocket, with the fabric/leather between (and moved it to the other side of its section). The big difference, other than attentiveness, is that I had it in a light crossbody pouch with just a couple things for the trade show, as opposed to the Summer purse with the magnetic mirror.

Lisa, I have masses of free space on it.

Anyway, I'm still mystified, but happy that it's behaving so well. I don't really want toast (phablet). :) I'll be charging it tonight, now that I'm home, and I'll see if I can get it back into a semblance of continuing good behavior.

I appreciate everyone's help! Thank-you!

I'd keep the data turned off. I never have mine on, unless I need it. And I seldom do.

My android phone battery sometimes depletes rapidly in my purse. I always think that I must have inadvertently activated an app or the camera.

I have to keep my phone on nowadays, Joan, because of potential emergencies for infirm relatives.

PKponder, perhaps that's it! A version of pocket dialing. The Summer purse is smaller than the Winter one, so I could see how something could press up against it. I think a piece of cardboard might be in order. ;)