What makes a cellphone battery become hot once in a blue moon when normally it hardly even gets warm?

The few times this happened, my cell was in my pocket with the camera on. The rising heat of course got my attention.

@mazingerz88 Ok. How long was the camera on and was it a long time ago?

External temperatures maybe are in play here.

Too many programs open in the background. Make sure to give permission to most of them to only run when opened and make sure you close all your tabs. When you have a lot of tabs open they are still pulling energy from your phone. My new phone was like that and it’s because I have a lot of games on them and kept switching from one game to another. Also, the higher specs of a game will cause your phone CPU to work harder. I could kill my battery charge a lot faster depending on which games I played.

So I got rid of the games that sucked my battery dry and only kept the simpler ones. Try doing these things and if your battery is still running hot then you may need a new phone. Oh, and make sure you have wifi off when you aren’t home. Your phone will keep roaming for a signal and that will also kill your battery. When home you can also cut off your blue tooth if you don’t need it for anything much.
Playing movies on your phone will also make your phone work harder and doing video calls can also make it work harder especially if you aren’t using wifi from your home.
Another thing. Don’t play games on your phone while charging. This will diminish your battery’s life.

@rebbel and @Pandora it has never been hot even on the hottest of days, (40°C) it hardly gets warm but on a cold fall day, hot. By the way everything the same activity wise. (Edited)

What kind of phone do you have, @Flo?

@chefl If you have changed nothing in usage and this is something new to your older phone check to see if your phone has been cloned. Run whatever virus protection you have and clean your phone out. Maybe your data is just full. There should be programs on your phone that allow you to see the health of your phone and your battery usage.

If all of this checks out then it may be you just need to change your phone battery. I don’t know how effective those health checks are but if the phone is over 2 years there is a chance that it could also be your phone is just going bad. Try switching the battery first. If it still continues then your phone is probably just going bad.
Also did you maybe ad a new cover to your phone that may be holding in heat or have left it in a hot car recently?

Mine did that once. It is a 2018 vintage Motorola MotoX. I had it in my pocket like a usually do but this time I felt a hot spot.
I shut the phone off and turned it back on. Everything was fine after that.
Now I only turn on GPS location if I am traveling or in an unfamiliar area. I turn off Bluetooth and only turn it on if I need it. And I shut off my wifi when I am not at home. Those three things made a huge difference in battery life. .

@Pandora “Re. If you have changed nothing…” it’s not my phone, and by the way it’s the battery that gets hot, once in a very long while, If the person didn’t need to remove it and then put it back to solve a probelm he wouldn’t have any idea the battery was that hot.

@chefl Not understanding your last reply, but do what you think is right. I was just trying to help you figure it out. I can’t mind read phones, just stating what are the most common problems.

@LuckyGuy What made it hot?the GPS and the wifi and bluetooth? I don’t think the person is using GPS etc. Also re. the wifi the when not at home part I don’t understand. It’ll come to me maybe.

@Pandora I was responding to your first post. Re. your 2nd post, it’s not my phone, I’ll let the person read it. Adding: the activities are the same (and none of battery consuming things) and yet it’s only 2 times per yr average that it got hot.

No games, very few apps, no use of GPS, no camera on etc.

The temperature of lithium ion batteries rises rapidly when asked to discharge rapidly. In other words, just use less power and your battery will generate heat more slowly and therefore stay in a reasonable temperature range.

Any program that runs constantly will cause heat and drain the battery. Games and GPS programs, and audio/visual programs, tend to need to do things constantly, but it could be any apps programmed to run intensely.

So it depends what programs are running. Sadly, mobile devices are notorious for running programs that people other than the user really want to be running.

@chefl When you are away from your house your phone’s wifi is constantly working, trying to make a connection. It is pinging back to other wifi routers when you get in range. Since you have no intention of convecting to storage routers there is no point having it on. If you have “location” turned on your phone is constantly processing gps signals. If you don’t need it, turn it off. These are really easy settings on an Android phone.

My phone sometimes gets hot due to apps getting stuck on (intentionally or due to programming errors). e.g. FB and CNN. Usually killing the app will cure it. Sometimes I have to reboot the phone to make it quit.

@LuckyGuy I see what you mean.

@All, nothing other than browsing the internet. No heat producing activity.