Can A UPS Battery Backup Catch Fire?

An uninterruptible power supply (UPS) is meant to be a backup for when there’s a power disruption. But, unfortunately, it can also suffer from several problems. In severe cases, it can even catch on fire.

Yes, a UPS battery backup can catch fire. Several reasons, like clogged air vents or fans, short circuits, cooling system failures and excessive float voltages, can happen. Bottom line: a UPS will catch on fire due to reasons that lead to overheating or electrical faults.

Check out this guide to discover the most likely reasons a UPS might catch on fire and how you can prevent them.

Can A UPS Catch Fire?

Yes, an uninterruptible power supply or UPS can catch fire. That’s why it’s crucial to maintain the device regularly and monitor it closely. Should the UPS experience any problems, you must fix them as soon as possible.

There are several reasons why a UPS might catch fire. Still, all those possible reasons share two things in common:

  • Overheating: It’s normal for a UPS to run a little warm. However, there are plenty of problems that can cause it to overheat. Should that overheating become too severe, it could cause the UPS and its components to catch fire.
  • Electrical faults: All UPS devices contain batteries and the electronic components that manage them. All of them can suffer damage and excessive wear that leads to electrical faults. Unfortunately, those faults can trigger electrical fires that burn the UPS battery backup.

The most dangerous threats to a UPS are excess heat and electrical faults. In the next section, we’ll take a more detailed look at the problems that can trigger either of those things and cause your UPS to catch fire.

Read: How To Troubleshoot UPS Battery?

What Can Cause A UPS To Catch Fire?

Below are the most likely reasons a UPS battery backup unit can catch fire and how you can repair or prevent it from happening:

Blocked Or Clogged Air Vents

What it is: UPS units have air vents built into their casings. An air vent’s purpose is straightforward: it increases ventilation and allows heat to escape the UPS into the surrounding atmosphere.

Some UPS models might include a fan to increase that ventilation further. Still, whether or not there’s a fan, there will undoubtedly be air vents.

How it fails: Wherever there’s airflow, there’s dust. That’s true for the air vents on a UPS as well. So while most dust will get blown away by the air, some will get stuck in and around the air vents.

Connect with an Appliance Repair Tech

Click here to use the chatbox to speak with one of our technicians.
No in-home service calls. No appointments.

Over an extended period, more dust will build up around the vent until it becomes severe enough to restrict airflow.

When that happens, heat generated by the UPS can’t escape. The unit will eventually overheat to a point where the dust or internal components will catch fire and burn the UPS.

How to fix or prevent it: The good news is that this problem is entirely preventable. You can avoid it by regularly wiping the air vents clear. Alternatively, a low-power vacuum can suck away dust and maximize airflow through those vents.

Read: How To Check UPS Battery Health?

Short Circuits

What it is: Earlier, you read that electrical faults can trigger a chain reaction causing a UPS to catch fire. Well, one of those electrical faults is a short circuit.

Short circuits happen when the electrical current flows in the wrong direction, causing an overload and leads to excessive heat. That heat will combust and start a fire that burns from within the device.

How it fails: A short circuit can happen for several reasons in a UPS. For example, low-quality components inside the battery degrade and lead to an electrical failure. Or, those components could have suffered damage during transportation or a repair.

Besides that, the battery’s positive and negative plates become connected, leading to a short circuit.

How to fix or prevent it: Firstly, you should always invest in high-quality batteries and components for your UPS. Never skimp on things like battery replacements as the risk of a fault is higher.

Besides that, repairing a UPS manually can be very challenging or dangerous. So, it’s always best to let a qualified technician do it for you to prevent unwanted outcomes like short circuits.

Read: What Happens When UPS Battery Fails?

UPS Or Room Cooling System Failure

What it is: Above, you saw that all UPS units come with air vents to keep themselves cool. Still, different UPS models will have various cooling features built into them.

Aside from air vents, larger capacity UPS devices might also come with built-in fans to remove hot air from within the device.

Furthermore, industrial or heavy-duty UPS units, like those you’d find in data centers or server rooms, will require much more intensive cooling. Therefore, these units are typically placed in spaces that have a cooling system of their own.

For example, those rooms have air conditioning units that always keep the room cold.

How it fails: A UPS backup battery can tolerate excess heat for a short period. However, it can immediately catch fire when its fans or the room’s air conditioning fails, and the UPS reaches dangerous temperatures.

How to fix or prevent it: This problem is preventable with regular cooling system maintenance. You must clean the fans and air vents regularly if you have a standard desktop UPS.

Besides that, you must also replace any spoiled or broken fans immediately.

However, if you’re using a heavy-duty or industrial UPS, the room’s cooling system should have backups (also called ‘redundancies’). 

For instance, if one air conditioning unit fails, there should be a second one to act as a backup and keep the UPS safe.

Read: How To Tell If UPS Battery Needs Replacing?

Excessive Float Voltage

What it is: Your UPS float voltage is another crucial factor you must be aware of. The UPS is meant to be plugged into a power source despite being fully charged. 

The float voltage is the voltage that the UPS maintains for its battery. When that voltage is correct, it will maintain the full battery without overcharging it.

How it fails: Your UPS has electronic components that control how it charges and maintains its batteries. Inside, you’ll typically find a printed circuit board (called the control board) that houses all those components.

The control board and its components also control the float voltage and prevent the battery from overcharging. Unfortunately, suppose those components are faulty or damaged. Then, they can cause the battery to overcharge, generate excessive heat, and catch fire.

How to fix or prevent it: Suppose you discover that the electronics in your UPS are faulty or damaged. In that case, you must replace the control board as soon as possible.

More importantly, immediately disconnect the UPS from the wall socket. Leaving it plugged in will increase the risk of a high float voltage and UPS fire.

Read: What Are UPS Battery Failure Symptoms?

Frequently Asked Questions (FAQs)

Here are more questions and answers to help you troubleshoot your UPS:

Why Is My UPS Overheating?

Your UPS is overheating because its air vents and fans are clogged with dust. If your UPS requires low ambient temperatures, check that the room’s air conditioning is functioning correctly.

How Do I Clean My UPS?

Clean your UPS by brushing away dust in or around the air vents and fans. You can also use a vacuum on its low-power setting to clean your UPS. Never use a wet cloth to clean the unit.

Do UPS Need Maintenance?

Yes, your UPS requires regular maintenance. That includes cleaning away any dust from its air vents and fans. Besides that, you should also run the self-test feature (if it has one) and check for any error codes.

How Much Airflow Does A UPS Need?

You should give your UPS at least two inches on all sides to ensure it has sufficient airflow and ventilation.

Why Is A Cooling Fan Needed In A UPS Unit?

A UPS generates heat from within, particularly when charging or discharging its battery. The cooling fan helps to remove that heat and keep the UPS within safe operating temperatures. Protection Status