Cell phone mystery

[malonetd]

I don't have an answer for you, but my thoughts have always been the same as yours. I have a friend who gets poor reception at his house and my phone's battery always seems to die so much quicker there. Like you, I assumed it used extra energy searching for a signal.

I would love to hear someone knowledgeable weigh in on this.

[TheConfessor]

I've always had the same experience with batteries discharging faster when the phone has to work harder to find a connection. You might want to use your Ask The Expert lifeline. I suggest Bill Nye, The Science Guy.

[Amanda]

My best friend's grandparents own an old house on the coast of Maine (with no cell phone reception), and my friend had her birthday party there last year, and everyone's phones kept losing charge. At the time we attributed this to the ghosts that haunted the third floor, since one girl who was there was an avid watcher of Ghost Hunters and on the show they say ghosts suck energy out of phones and batteries and whatnot. Later another friend who works at an Inn says that happens all the time where she works because there's no cell phone reception. So either you were living with ghosts, or your hunch is correct.

[Cartophiliac]

What you've all said above jibes with what I've heard...

Another thing I learned recently, but should have been able to figure out on my own: Setting your phone to vibrate runs down the battery soon than just a ring tone. Takes a lot of juice to make your phone dance.

[jesseg]

A weak signal is definitely the cause. Even though my girlfriend lives on the Upper East Side in Manhattan, I still get terrible reception from Sprint in her apartment. If I forget to set my phone to roam-only, my battery will be dead within a few hours. I've noticed that when my phone switches from Sprint to roaming, the backlight lights up. I'm sure that that, in addition to changing networks, is what drains my battery.

[jzerocsk]

Yeah there's 2 components, I believe - one is that the phone basically kicks up the gain looking for a signal. The other (which may no longer hold sway with modern cellphones) is that once connected, network optimizations also reduce the battery consumption.

I actually read once that salt marshes actually help radio signals travel farther. Not sure how true that is.

[NZ Bruin]

I agree Ken...

The worst, however, is when you accidentally leave your phone on when on a flight. Take-off with a fully charged battery, land with a fully discharged battery - not ideal!

[hairgami_Master]

Here's a thought: If you live in an area where your carrier's data service is the "Edge" (not David Evans) and you vacationed in an area where the carrier had the more robust 3G network, your battery life will be less than what you're used to. The answer is more difficult to ascertain because I assumed you wouldn't allow in-laws to bring phones to the beach.

[Don WW]

Witches.

[burgels]

This always happens to us in remote areas. We generally turn our phones off unless we need them to keep them from draining their batteries searching for a signal.

[Baylink]

I *do* have an answer for you, and not anecdotally. :-)

When a cellphone or pager is locked up with its system, it goes into a low power idle mode where it monitors one timeslot (generally, out of 6, I think) on the system's control channel, looking for a packet that says *it* should wake up and ring. The other 5/6s of the time, the radios are all shut down and don't draw power.

When it can be in this low-power mode, the battery life is what you'd expect.

When it can't find a system to lock up to, then it has to listen to *all* the timeslots in idle mode, not just one, and the power consumption at idle is something like 6 to 7 times as high.

This apples to modern CDMA and GSM air interfaces, as well as the ones used for paging in the past, POCSAG and FLEX, and probably others.

I had a PrimeCo/Verizon CDMA phone (the QCP-1900, by name) surprise me this way on a roadtrip about 10 years ago; it was the first time I took it out of the Tampa metro (which was all they covered at the time), up to Ocala FL. Was dead by the end of the day, when 2-3 days was the norm.

[MiniBen1]

My friend who sells cell phones once told me that when you get to a more rural area and your phone does not detect a digital signal, it switches to analog. Now, with a digital signal your phone only searches out for a connection every 10 seconds, or so, but with analog it's constantly searching for a signal and this will drain your battery really fast. Like the earlier poster who doesn't get reception in his GF's apartment, no signal there, switches to analog, drains the battery.

[Baylink]

Well, if you still *have* a phone that speaks analog, since the entire AMPS service was turned off nationwide over a year ago...

[ChadHahn]

I went to visit my mother in a small town in Iowa that had no cell phone reception. My cell phone would go dead overnight looking for a signal.

Chad

[Alice Mayer]

I had a PrimeCo/Verizon CDMA phone (the QCP-1900, by name) surprise me this way on a roadtrip about 10 years ago; it was the first time I took it out of the Tampa metro (which was all they covered at the time), up to Ocala FL. Was dead by the end of the day, when 2-3 days was the norm.

[jessy27]

Ken,
I live just outside Virginia City in Nevada, everytime I go there (it was settled in 1850) my phone will be dead by
the time I get home. It's got to be ghosts lots of ghosts in Virginia City.

[steveosiris]

I don't have an answer for you, but my thoughts have always been the same as yours. I have a friend who gets poor reception at his house and my phone's battery always seems to die so much quicker there. Like you, I assumed it used extra energy searching for a signal.

I would love to hear someone knowledgeable weigh in on this.

The reason why the phone battery dies much faster is because your phone wastes a bit of battery while searching for a signal. If there is a weak signal, this will cause the phone to die much faster. If you have an iPhone, you can change the type of signal you are getting if you turn the 3G off when there is a bad signal, and this should conserve your battery. Also, if you have your cell phone linked with your residential VoIP PBX software, it could conserve battery because Voip drains a lot less battery than 3G. Hope this helps.
-Steve