APC Battery Backup Burning Smell. What Are The Causes And How To Fix Them?

APC battery backups are silent devices that often go unnoticed until a power disruption. Aside from producing little or no sound, the unit should also have no smells. That’s why a burning smell from the APC battery backup indicates a severe problem.

An APC battery backup will give off a burning smell if unremoved packaging materials are overheating and burning. Besides that, a faulty or damaged battery can also produce the same odors. More importantly, overheating and short-circuits are dangerous problems that make burning smells. 

The following sections will guide you through the precautionary steps you should take if your APC backup battery is giving off a burning smell. Then, you’ll discover the reasons for that smell and how they can be fixed.

What To Do If Your APC Backup Battery Has A Burning Small?

First and foremost, you must understand that a burning smell from your APC battery backup can be hazardous. Never underestimate the danger that an APC backup battery can pose if it gives off a burning smell.

So, before you begin to troubleshoot the unit or try to repair it, here’s what you must do first:

1. Disconnect: As soon as you detect a burning smell from your APC unit, shut it off and disconnect it from the wall socket.
2. Unplug Batteries (If Possible): If you know how to open the backup battery casing, you should also unplug the internal battery. You should only do this if you can do it safely with the necessary knowledge and experience.
3. Bring UPS Outside: Next, bring the UPS unit outdoors and place it in a safe, well-ventilated area, so no one breathes in the smoke or other fumes. You should put it far away from the building as it might catch fire.
4. Call A Technician: You should call a technician to service the UPS. Fixing it yourself can be very dangerous unless you have the necessary skills. So, if you’re unsure at all, let the professionals handle it.

Read: How To Reset APC Battery Backup?

Why Does My APC Backup Battery Have A Burning Smell?

Now that you’ve put the backup battery in a safe location, here are the most likely reasons for that burning smell and how a professional might repair each one:

Unremoved Packaging Materials

What it is: The first cause to consider when there’s a burning smell in your APC battery backup is the presence of unremoved packaging materials.

All battery backups come with packaging materials that keep them safe during shipping, especially when you buy them brand new. That will include boxes, packing peanuts, and other items that prevent damage to the unit.

Besides, some models also have a pull tab between electrical contacts within the device. Those tabs ensure that no electricity flows through those contacts while the device is stored or shipped to a buyer.

You should remove all packaging materials from your UPS before you use it for the first time.

Why it happens: Unfortunately, some packaging materials might go unnoticed when buying the APC battery backup unit. 

So, when you plug the battery backup into the wall socket and begin using it, the unit’s heat will cause the packaging materials to burn slightly, giving off that burning smell you noticed.

How to fix it: The solution to this problem would be to remove all packaging materials before you use your APC battery backup. You should inspect the unit thoroughly to ensure that you didn’t overlook or miss any packaging materials that came with the unit.

You can also check the user manual to be sure. There is likely information in the manual about steps to take before using the battery backup for the first time.

Read: Why APC Battery Backup Not Charging? – Troubleshooting Guide

Faulty or Damaged Battery

What it is: The batteries inside your APC unit can also suffer from faults or damage. A damaged battery will present various symptoms, including bulging and a significant drop in performance.

More importantly, a faulty or damaged backup battery can also overheat and give off a burning smell.

Why it happens: Backup batteries typically become faulty or damaged due to extended wear. In other words, the older the backup battery, the more likely a problem like this might happen.

However, you can also experience the same problems if you replace your backup battery with a lower-quality one.

How to fix it: Firstly, the faulty or damaged battery must be removed immediately. Leaving it connected to the APC unit is dangerous as it could overheat and explode or produce more toxic smells.

Secondly, the battery must be replaced with a new one. Faulty or damaged batteries cannot be repaired.

Read: How To Troubleshoot UPS Battery?

Overloading And Overheating

What it is: Another reason an APC battery backup gives off a burning smell is that the battery and circuitry are overloaded. That overloading will generate plenty of heat, giving off that burning smell you notice.

Why it happens: An APC backup battery becomes overloaded when you plug too many power-hungry devices or appliances into the unit.

As those devices drain power from the APC backup battery, the unit will experience a current that’s too high that causes the battery to generate too much heat. 

In turn, that heat will burn the battery’s casing and other plastic parts inside the APC unit.

How to fix it: You can fix and prevent this problem from happening by ensuring that you don’t plug heavy-duty appliances into your backup battery. 

The user manual is the best reference for this, as it states the capacity of your APC model in particular. From there, you can check the power demands of your devices and appliances to ensure you’re not overloading the APC unit.

Read: Why Ups (Battery Backup) Is Beeping Continuously?

Short-Circuited Electronics

What it is: An APC battery backup consists of an internal battery and electronic components that control the unit’s functions. The most common example is the control board, a printed circuit board (PCB).

The control board can experience short circuits and other electrical faults like other electrical components.

Why it happens: When a short circuit happens inside your APC battery backup, the affected components will overheat and burn. That will lead to several outcomes, including a powerful burning smell that you will quickly notice.

How to fix it: Short-circuited control boards and other electronic components are not repairable. Therefore, the only solution is to replace them with new ones.

Replacing those components inside an APC battery backup can be risky if you don’t know what you’re doing. So, always err on the side of caution and let a qualified technician do it for you.

Read: How To Check UPS Battery Health?

Frequently Asked Questions (FAQs)

Here are a few more frequently asked questions and answers to help you troubleshoot your APC battery backup:

Why Is My UPS Warm?

You’ll find that your APC UPS feels warm when operating normally. That’s because the electric components inside experience electrical resistance that converts some power to heat. As long as the unit doesn’t become too hot, it’s functioning normally.

Do UPS Batteries Leak?

Yes, UPS batteries can leak. However, leaks become more severe as the battery ages and experiences extended wear. Besides that, low-quality batteries also are at higher risk of leaking.

Do UPS Batteries Smell?

No, there should be no smells coming from your APC UPS battery. However, suppose you notice any smells, like a burning or rotten egg smell. In that case, you should disconnect the unit and send it for servicing. Those smells are a sign that the battery is experiencing a problem.

How Can I Keep My UPS Cool?

The best way to keep most UPS units cool is to place them in a well-ventilated area away from any heat sources. However, heavy-duty, industrial UPS units might require air conditioning to stay cool. Always refer to the user manual to find the manufacturer’s recommendations for cooling the UPS.

Should A UPS Be Hot?

It’s normal for a UPS to be slightly warm. However, a UPS that’s hot to the touch is experiencing a problem. Disconnect the unit immediately for safety reasons, then send the unit for servicing by a qualified technician.