When my wife is at work, not on wifi, her battery will last all day. She comes home and she's at about 80% and then within a couple hours of getting home and connecting to our wifi, she's at about 15%. Everything I've research says that wifi takes less power than 3G/4G/LTE, but it seems to be exactly the opposite in the case.
What can I look for?
Protect & Prolong life of your iPhone's Battery:
She must be using it pretty continuously or at least keeping the phone awake, because Wi-Fi turns off 30 seconds after the phone goes to sleep. Wi-Fi uses 30 mw continuously when the phone is unlocked. Cellular uses 50 mw to 500 mw depending on signal strength, but only for a few ms at a time.
Lawrence,
That's what doesn't make sense to me. She was home sick today and slept for about 4 hours. When she went sleep, it was at 86%. When she woke up it was at 17%. She does use it heavily normally, but that seems odd to me. I can try the standard things...brightness, app refresh, turn off hotspot and all that and then see if it makes a difference. I just think it's strange that it drains so much faster at home than anywhere else.
Thanks for the reply, Lawrence.
I just think it's strange that everything online seems to indicate that wifi should take less power than LTE, but her battery drains like crazy when she's home on our wifi network. I've tried looking at battery utilization, but that is inconclusive. I'm not sure where else to even look at this point.
Without a more in depth analysis its hard to say. However, Wi-Fi uses data (and thus energy) continuously when connected whether data is being transferred or not. Cellular data only uses energy for the duration of each transmission. Also, cellular only uses substantial energy for sending; it uses less than Wi-Fi when receiving.
You are assuming the drain is from Wi-Fi. But if the phone is locked it has nothing to do with Wi-Fi. Go to Settings/Battery and see which apps are using the most energy.
Why does my wife's iPhone battery drain more than twice as fast on my home Wi-Fi than when I'm away on LTE?
