Battery life and signal strength

Discussion in 'iPhone' started by bp1000, Jul 11, 2013.

  1. bp1000, Jul 11, 2013
    Last edited: Jul 11, 2013

    bp1000 macrumors 65816

    Jul 7, 2011
    I'm trying to understand the effect signal bars has on battery life.

    I've moved providers and my old provider gives me 4 bars and -84 to -89 / -15dBm to -6dBm and the new provider 3 bars but it fluctuates between 1 and 3 bars at -97 to 103dBM / 0dBm to 3dBm transmit power.

    Is that significantly worse power consumption to affect battery life? It seems worse but hard to tell with these things.

    New carrier has much better 3G coverage and 10x the speeds. I get 3G everywhere but maybe only 1 or 2 bars in places where as old provider falls back to 2g a lot.
  2. Lucille Carter macrumors 65816

    Jul 3, 2013
    Poor reception is a factor in battery consumption, not a doubt about it.
  3. CTHarrryH macrumors 68000

    Jul 4, 2012
    I find that signal strength is the biggest single factor to me for battery life. I do generally the same thing with my phone every day. Where I used to live I had great signal strength except inside some buildings - my battery life was great. If I spent a lot of time in those buildings or where I live now which has poor signal strength my battery goes down twice as fast.

    Bad signal strength means the phone has to sometimes try several times to get messages or send them etc. While it is doing this retry it uses the battery more.
  4. madsci954 macrumors 68030

    Oct 14, 2011
    Yup, and it's not just iPhones. I used to use an old flip phone before I moved to smartphones, and it would last several days on one charge. But if I left it in my work locker, which was already in a poor reception area, it would be dead after an 8 hour shift. Even with a full charge the night before.
  5. bp1000 thread starter macrumors 65816

    Jul 7, 2011
    It does seem that way

    Im seeing around 25% decrease in battery life since switching to this new network. Measured in the same place. Same average usage.

    That's going from 4 bars to 2 bars average.

    I was hoping a bad signal on 1 bar would show the most problems.
  6. Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    Lower signal quality tends to use more battery. On standby if you lose signal, the phone will use more power trying to re-acquire a signal than it would with a constant signal. Also with a weaker signal the phone may have to retransmit more and therefore use more power that way.
  7. bp1000 thread starter macrumors 65816

    Jul 7, 2011
    Would a smartphone also increase battery usage with a full 2G signal by trying to find a 3G signal again?
  8. Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    It depends on how the smartphone was coded. If it knows you haven't switch cell towers, why try finding a 3g signal again?
  9. thelatinist macrumors 603


    Aug 15, 2009
    Connecticut, USA
    Exactly. Cell phones are limited, I believe to 1 watt maximum transmission power; but most of the time they use significantly less. If a phone is in a marginal area, it can maintain a signal by increasing the transmission power -- but it comes at the cost of a huge hit to battery life. And in such areas you are far more likely to have an intermittent signal that requires constant reconnect attempts.
  10. bp1000 thread starter macrumors 65816

    Jul 7, 2011
    So as I gather from your info

    Fringe areas / black spots are likely to use much more battery than compared to having a consistent 2-3 bars.

    So as signsl decreases so does battery life, which is hit particularly hard when the signal is so weak it has to boost transmission power and keep hunting
  11. AutoUnion39 macrumors 601


    Jun 21, 2010
    Low signal areas are a killer for battery life, especially when your phone keeps switching between HSPA/LTE/EDGE.
  12. takeshi74 macrumors 601

    Feb 9, 2011
  13. MistahMumford macrumors 6502


    Nov 12, 2011
    Exactly. I use my phone more at home than I do at work but it dies faster at work where I'm consistently at two bars of 3G (turn off LTE in my building). At the house though on Wi-Fi I can pound on this thing with the usage and it'll last me almost the entire weekend.

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