# Cell phone power question--how quicky discharged **URL:** \ **Category:** Factual Questions\ **Created:** [August 16, 2007, 3:34am UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775 "2007-08-16T03:34:08Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [August 16, 2007, 3:34am UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/1 "2007-08-16T03:34:08Z")
I have a friend who told me tonight that she’s driving about 400 miles tomorrow. She has to pass trough West Virginia. Parts of WV have poor cell phone reception. She claims that if she starts out with a fully charged phone, by the time she gets to the end of her journey, after 7-8 hours, not talking on her phone more than perhaps 10 minutes during the trip, her phone is basically down to one power bar–discharged. Her explanation is that someone told her the phone spends so much time searching for a tower, that it uses too much power. I call bullshit. Can anyone give me a reason why this _might_ be true? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [August 16, 2007, 3:40am UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/2 "2007-08-16T03:40:43Z")
[QUOTE=samclem] I call bullshit. Can anyone give me a reason why this _might_ be true? [/QUOTE] Yep, it’s true. Cell phones attempt to connect to the network periodically in order to “tell” the network where they are. If they send out a “here I am!” signal at the lowest signal strength and don’t get one back from the network, they ramp up the power and try again. So, yes, being out-of-network will cause a cell phone to run down its battery faster. ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [August 16, 2007, 3:49am UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/3 "2007-08-16T03:49:04Z")
If a phone cannot be connected to a system it does have to search for a system. This means it has to have the radio on to listen for the system. If the phone is in a system and knows it the phone will only turn on the radio every couple of seconds to listen to see if there is an incoming call. Keeping this listening time down to a minimum is how phones increase their stand by time. ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [August 16, 2007, 9:46am UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/4 "2007-08-16T09:46:05Z")
You can get the same effect by spending time inside a well-shielded building. Your cell phone will rapidly run down its battery while attempting to find a network. I used to have a cell phone (CDMA/AMPS) that would get noticeably warm in that situation. ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [August 16, 2007, 12:57pm UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/5 "2007-08-16T12:57:02Z")
One other thought: Any chance the battery is old? Performance does start going downhill at some point, in my experience. But if her charge otherwise lasts a long time, that’s probably not the situation. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [August 16, 2007, 1:01pm UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/6 "2007-08-16T13:01:17Z")
My Wife and I have the same problem. If we leave our cell phones on at home they will discharge in about 8 hours. This is one of the reasons I rarely leave it on. While I was in Boulder over the weekend, I was amazed that it stayed charged for two full days. ---
**Author:** ![butler1850](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@butler1850](https://boards.straightdope.com/u/butler1850)\ **Post date:** [August 16, 2007, 2:35pm UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/7 "2007-08-16T14:35:43Z")
I see this exact same issue when I head north of cell coverage in NH to go hunting/camping. On a full charge, it will completely deplete overnight. In good coverage areas, it can last for 3-4 days. My new phone doesn’t seem to have this issue. ---
**Author:** ![Potato\_Pancakes](https://avatars.discourse-cdn.com/v4/letter/p/65b543/32.png) [@Potato\_Pancakes](https://boards.straightdope.com/u/Potato_Pancakes)\ **Post date:** [August 16, 2007, 2:57pm UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/8 "2007-08-16T14:57:45Z")
Yeah, this is why I don’t keep my phone in my desk at work. It’s more of a drain on the battery that way. ---
**Author:** ![vetbridge](https://avatars.discourse-cdn.com/v4/letter/v/b5e925/32.png) [@vetbridge](https://boards.straightdope.com/u/vetbridge)\ **Post date:** [August 16, 2007, 3:13pm UTC](https://boards.straightdope.com/t/cell-phone-power-question-how-quicky-discharged/415775/9 "2007-08-16T15:13:28Z")
I also have witnessed this effect. My battery will be fine for 2 days in my home. Traveling through areas with “Roaming” occurring, I am lucky to go a day. During a cruise in the Caribbean, I would be lucky to have the battery last 5 hours after a full charge.