It's quite rare that actual signs of your phone battery's deterioration show up. However, there are some subtle indications you can use as a telltale sign that it's about time for iPhone battery replacement. 

If any of these warning signs are present on your iPhone, you may need to replace it sooner rather than later — because in the long run, even if you don't notice the battery issue now, it will only get worse and cause more problems down the road.


Here are a few subtle signs that might indicate your iPhone needs to come in for service:


• Your phone won't turn on at all. You can probably power it on, but the battery is completely dead, so there's no reason for it to work.

• The phone takes more than a minute to turn on. If you have a new iPhone, you'll notice that after about 15 seconds of idle time, the phone will start up and keep going for a while (although this may vary depending on your phone model). 

• The phone shuts down right after turning on. You pop the back open and charge the battery, but when you hit the "on" button, the screen goes black, and nothing happens. 

• The battery is completely dead — and no charge will get it to full life again. If you pop the back-off and plug it in, it shows that it's charging but will never get past 1 percent. 

• The phone gets hot every time you charge or start using it. This happens to all cell phones — because they have integrated circuits and other elements of their design that require energy to power up — but if you notice your iPhone gets extra hot when you try to turn it on, this is a sign your battery is already on its way out.

• Your phone won't receive a signal from the tower or wifi access point. This can be a problem because it prevents you from texting, checking email, or using the internet.


Conclusion


If you notice these signs — or if any of your friends or family members can tell you they're experiencing them — it's time to get your phone in for service.