May 13, 2013
Fremont, CA
I've shut down all the background apps that I don't use, and generally I get 3 to 4 days between charges (phone turned on all the time, but only actively used for a few minutes per day).

However, I have a problem when I go out of town to go hiking. In the area where I hike, I typically lose the connections entirely - no phone, no data. When this happens, the phone (ZTE N9120 Avid 4G) seems to go into a hyper-search mode, and it typically drains the battery to 0 in about 3 HOURS !!!

I've started manually putting the phone in airplane mode if I know I'm going to such an area, but I would really like an app that would intelligently handle the search, as in "If I lose signal, and can't get it back after 5 minutes of trying, go into airplane mode for 15 minutes, then try again. Rinse and repeat.".

I don't want the app to do anything else, like turning things on and off generally, I just want to manage this no-signal situation.

Is there any app that will do this?? I've looked at GreenPower and JuiceDefender, and Advanced Mobile Care; they all do alot of other things, but they don't appear to actually address this specific issue.
Unfortunately, I think your manual solution is the best. In order for ann app to do that the antennas would need to be powered up (Airplane mode powers them down) and when they don't have a signal or they have a weak signal, they go berserk hunting for a stronger one.

You may be better off hunting for an app that lets you know when your signal is weak or lost and gives an audible / vibrate notification to conserve your battery.
Two things:
1) it sounds like you could also turn off sync to prevent the phone from trying to update
2) sounds like tasker MIGHT be able to do what you want
Couldn't he do this with Tasker? It's not like he's asking it to stay in airplane mode until it detects a signal (impossible, as you say), he just wants it to go to airplane mode for 15 minutes, spend 5 minutes out of airplane mode, and if no signal is found go to airplane mode for 15 minutes again.

There's probably an app for it, but what kind of search would you use to find it? Everything I can think of brings up all kinds of stuff that's not quite right.
You should be able to do this pretty easily with a powerful tool, like Tasker.

I think you can even do it with the less powerful but (free, open-source) Llama (which is what I use) by having the phone go into airplane mode after X minutes of no-service, and then waking up every Y minutes to check for service. I just created such an "Event" in Llama but I don't really have an easy way (nor the time) to test it. In Llama, I think the instructions would be as follows for this "Event".

Conditions (to select):
1) "Mobile data not connected".
2) "WiFi not connected".
Then select "Advanced..." and check "Delay event" and choose the amount of time (e.g. 5 minutes) that you want the phone to wait before going into airplane mode. Also check "Cancel delayed if false". That way the phone will only to into airplane mode if you lose service for 5 straight minutes.

Actions (to take):
1) "Toggle Airplane Mode On".
2) "Queue another event". (E.g. Call it "Sniff for service".) Select the desired Queue delay (e.g. 15 minutes) with an "Action" of Toggle Airplane Mode Off".

The result should be as follows (I think). Any time you lose a data connection (cellular AND WiFi) for 5 minutes straight, the phone goes into airplane mode but the phone wakes up every 15 minutes to sniff for service and goes back down after 5 more minutes of no service.

There might be several other solutions through Llama since you can have Llama take certain actions based on your proximity (or lack thereof) to certain cell towers.

FYI: My phone not only burns through batteries if it loses its cellular connection, but it also burns through batteries if it's even roaming. (My Sprint plan has free roaming onto Verizon, and I'm sure Sprint has to pay Verizon for the minutes/data so I guess Sprint programs their phones to work like crazy to get off of Verizon's service ASAP.) If I turn roaming off, I can save some juice when I'm outside of Sprint coverage. Also, somebody hacked an app that is specific to my LG Optimus S phone which lets me lock the phone into roaming-only mode thereby saving juice if I'm in an area with Verizon service but not Sprint service.
heh... @divinebovine hit the problem right on the nose!! What exactly do I search for, to try to find an app for this?? I tried half-dozen search phrases, but always ended up back at either of the apps that I previously mentioned, neither of which appear to do the specific task that I need!!

I'll check out Tasker and see if it will service.

The problem with just handling the situation manually, is that I don't always know when my phone loses its signal; I use SignalChecker Lite to display this information, but it doesn't do anything automatically.

The weekend before last, I was up on Alameda Island (California)... I checked my phone a couple of times and signal was fine, sitting at about 70% charge... then on the way home I tried to wake it up to check traffic on i880, and it had powered down; when I tried to turn it on, it was at 7%, and turned itself back off again!!!

So, I don't always know when it's in its crazy mode - that's why I need an app to do the thinking for me!!
The problem with just handling the situation manually, is that I don't always know when my phone loses its signal; I use SignalChecker Lite to display this information, but it doesn't do anything automatically.

I see. I (and I think the others) were thinking you'd just stick it in airplane mode before going somewhere with spotty coverage, rather than waiting for coverage to drop.

How about something that plays a notification sound when you lose/gain connectivity? I vaguely remember something like that (except of course with a simple beep) being common in the early days of cell phones, or maybe it was something else that depends on a spotty signal...
Thanks for all the suggestions, all!!
@RazzMaTazz: I was looking at Llama, and it would probably have eventually worked, using the "signal strength" variable that he added in a recent beta version. However, I then looked at Automagic Automation, which (though not free), easily offered the function that I was looking for:
IF (signal lost)
THEN (enable airplane mode)
I tested it this weekend up at Welch Creek Road, and it worked perfectly!! I'll want to refine it a little, but I can easily do so. Well worth $4, methinks...