Every cell phone owner knows the frustration of losing power at just the wrong moment. Whether you are navigating your way around the city, on a business call or conducting research on your way to a meeting, the second you lose power, your productivity is frozen.

If your phone cuts out or won’t start at all, you will likely wonder if the phone itself is damaged. Luckily, cell phone batteries rarely cut out suddenly. There are symptoms of a bad cell phone battery to give you a better idea of what is going on. If you catch these signs ahead of time, you may be able to get the battery fixed at a cell phone repair service.

If your phone isn’t working properly, you should inspect for these eight symptoms of a bad cell phone battery:

Symptom #1: The cell phone battery charge doesn’t last.

We’ve all been there. Our phone was just charged this morning and by early afternoon, the battery life is down to 5%, even without excessive use. Cell phone batteries are designed to have a certain number of charge cycles. Fortunately, the general decline of a battery will usually happen over the course of these cycles. In other words, it will happen slowly.

At first, you may find yourself surprised that you have as little charge left as you do. While this slowly becomes the new normal for your phone, the battery continues to decline, giving you plenty of time to recognize that your cell phone battery maybe on its way out.

Symptom #2: There is a rapid decline in the battery life.

Sometimes, one of the most obvious symptoms pf a bad cell phone battery is how quickly it loses its charge. You may unplug your phone with the charge listed at 100%, but see it drop to 80% or 90% right away. While it is not uncommon for phones to lose a few percentage points in battery charge right away, an immediate drop off 10% or more is likely a clue that your battery is compromised.

Symptom #3: The phone is rapidly overheating.

While cell phones can get hot with use, constant heat can be a symptom of a bad cell phone battery. It’s a good idea to check the temperature of your battery while your phone is charging. If the temperature seems to be increasing each time you charge, chances are your battery is showing signs of failure.

Symptom #4: The phone is swelling.

Swelling or bulging in your phone can be dangerous. Cell phone batteries that are deteriorating can rupture and cause swelling. If your phone shows any signs of swelling, stop using it and take it in to be replaced. Phone batteries are generally safe, but it is better to make sure everything is working properly than risk damage to your phone or yourself.

Symptom #5: An outlet is required to charge your phone.

If your cell phone battery works only when plugged in, it is likely nearly dead or already there. Until you can arrange to have your battery replaced, you will need to stay close to a power outlet when you need to use your phone.

Symptom #6: The phone restarts on its own.

This can be a frustrating symptom of a bad phone battery. If your phone restarts itself while you are in the middle of something, without being prompted, you almost certainly need to have it replaced.

Symptom #7: The phone displays unreliable battery numbers.

While it is easy to understand and predict the declining charge on a battery when it is working well, a battery that is compromised will often quit unexpectedly, when there seems to be plenty of battery life left. This is a sure symptom of a bad phone battery. Take it for further analysis, whether the cause is a corrupt file on your phone or the battery itself.

Symptom #8: The phone has no power at all.

If your cell phone battery doesn’t charge after being plugged in, it could be a sign that your battery is already dead. Try testing the charger with another phone to make sure you have a battery issue and not a charger problem.

If you know your cell phone battery is struggling to keep and hold power, there are several things you can do to preserve its life. For example, avoid charging your phone too often. Batteries hold their power better when they are charged from a fully-drained status. If you charge your phone daily, out of habit, try charging it every other day, or when the battery is fully-drained. Also, avoid leaving your phone in extreme temperatures, either hot or cold, as both will prematurely drain your battery.

We hope these symptoms of a bad cell phone battery are useful in helping you to problem-solve as you figure out if your phone needs repair, or if you simply need a new battery. Remember, if you do need a new one, be sure to find the right kind of help—a trusted cell phone repair shop, one that will provide good service and will recycle your old battery properly.