I have noticed that 3 of my Android phones heat on low signal (Nexus4, Xperia U, and HTC One) 40~50C. My friend has an iPhone and it doesn't seem to heat as much (30C).
So, why does this happen? Why does low signal drain my battery, and why does it heat too much?
Could it be solved by software? or is it a hardware problem?
When the phone signals are weak, the android OS constantly scan the area thoroughly. This requires more battery power. That's the reason your phone gets so hot when you are in areas with poor reception.
That is the reason it is advised to turn flight mode on when you are is low-signal areas to preserve your battery life.
Yes. and that problem is common to all the android devices. So nothing to worry.
For the comparison with iPhone, the specs of android device of each manufacturer varies from one another whereas it doesn't in apple deceives (Not everybody get to produce a device which can run iOS, thanks to the Apple Inc. patents.) As the android specs vary from device to device, it is highly likely that the battery performance will differ from device to device as well.
Essentially, a lower signal strength will lead you device to use more power that in turn drains your battery faster and causes the device to heat.
The farther away you are from the closest cell tower, more your device needs to put out a higher power level in order to reach the tower. Transmitting at a higher power level requires more energy from the battery.
An elevated power level causes your device to heat in result of the extra effort being conducted.
If you are in a really weak signal area, try turning off Mobile Data. You can still receive calls and SMS (but not MMS).
I am also agree with the point mentioned by @Sid When there is no signal or low signal then system continuously scan the network that require more power from battery and it leads to battery heat-up.
That's why it is suggested that keep Airplane Mode off when it is not necessary.
There can be multiple reasons for the phone to heat up. Battery: If the battery is not working fine then the phone may get heated Charging port: If the heat is at the charging port then there may be chances that the charger is at fault. Too much of downloads: If you are used to continuously download something or the other then there are chances of the phone been heated due to excess load on processor No rest even at the time of charging: love to stay connected and not letting the phone charged then you are harming the life of the battery. Loads of apps and widgets that run round the clock- more pressure on phone: uninstall unnecessary load from the phone to avoid excess use of battery and processor Low air flow: keeping the phone in pocket where the airflow is less can also be the reson for phone heat up Phone exposed to moisture: long calls and continuous contact between hand and ear creates sweat on the screen and over exposure to moisture can also be the reason for hardware fault and thus heating up
