Why APC Battery Backup Not Charging? – Troubleshooting Guide

APC battery backups are always ready to continue powering your devices in the event of a power outage. However, that’s only possible if the battery can successfully recharge. So, why would an APC battery backup fail to charge?

Your APC battery backup won’t charge if there’s no incoming power supply. Besides that, a loose battery connector plug, wiring problems, or a blown fuse will also prevent it from charging. Lastly, old batteries will also fail to charge at the end of their service life.

Troubleshooting your APC battery backup is pretty straightforward. This guide will walk you through the likely reasons it’s not charging and what you can do to fix it.

Why Is My APC Battery Backup Not Charging?

APC battery backup units are pretty straightforward devices. So, if you find that the battery isn’t charging as it should be, here are the most likely reasons:

#1 No Incoming Power Supply 

What it is: Your APC battery backup should always be connected to a power source. That way, the battery will remain charged until a power outage occurs. When that happens, the battery will continue supplying electricity to your crucial devices to keep them operational.

How it failed: The first step of your troubleshooting process is ensuring that your APC unit receives a continuous power supply. Without that, the battery will have nothing to charge itself with.

More specifically, check these points on the APC unit’s power supply:

• The circuit breaker, i.e. the circuit breaker at your main electrical box that supplies power to your APC battery backup.
• The wall socket, i.e. the wall socket you use to power your APC unit.
• The power cable, i.e. the power cable that connects your APC battery backup to the wall socket.

A fault or issue at any of the three points listed above will prevent your APC unit from receiving the power it needs to charge.

How to fix it: The solution to this problem will depend on which part is affected. So, here’s what you’ll want to do:

• Circuit breaker: Firstly, check that the circuit breaker is in the ON position. If it isn’t, then push the switch to the ON position.
• Wall socket: Next, check that the wall socket you’re using for the APC unit is working. You can test it by plugging another device into that socket to see if it works. If it doesn’t, plug the APC battery backup into a functioning wall socket.
• Power cable: Lastly, check the power cable that connects the APC unit to the wall socket. It should not have loose connections or any signs of damage. If necessary, replace the cable.

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#2 Loose Battery Connector Plug

What it is: Inside each APC unit sits the rechargeable backup battery. That battery connects to the APC unit’s electronics through one or more battery connector plugs that supply power to recharge the battery.

That connection also allows the electronics to monitor the battery’s condition and sound any alarms if necessary.

How it failed: Another reason the APC battery backup isn’t charging is that one or more of the battery connector plugs is loose or has come undone. When that happens, the electrical power can’t flow to the battery to recharge it.

How to fix it: The solution to this problem is to open the APC unit and ensure that all battery connector plugs are firmly attached. That way, the battery backup can charge normally whenever the APC unit is turned on.

#3 Internal Wiring Faults

What it is: Aside from the battery connector plugs, the inside of an APC battery backup also has plenty of wiring to connect the components.

For example, there are wires connecting the battery to the main control board that controls its functions, including its charging activities.

How it failed: One thing that can prevent the battery from charging is one or more internal wiring faults. For example, the internal wiring could have loose connections.

Alternatively, some wires could have also overheated and burned due to an electrical fault.

As a result, electrical signals and power fail to go where they are needed, which stops the battery from recharging as it should.

How to fix it: Solving this problem will require a closer inspection of the wires inside the APC unit. You’ll have to disconnect the unit from its power supply to open it up.

Then, damaged wires should be replaced as needed, while loose wires should be pushed firmly into place.

Read: Why Is My Roomba’s Battery Not Charging?

#4 Blown or Burnt Fuse

What it is: A fuse is a sacrificial device that destroys itself to protect a circuit from electrical faults. Devices like the UPS battery backup rely on an electrical fuse to ensure that issues like power surges or short circuits don’t damage the entire unit.

How it failed: After you’ve finished troubleshooting causes #1 to #3, it’s time to consider that the electrical fuse might have burnt or blown out.

One way to check if the fuse has blown is to inspect it closely. Any visual signs or smells of burns indicate that the fuse has blown, likely due to an electrical surge.

How to fix it: Electrical fuses are not serviceable parts. Unfortunately, that means you can’t fix it. Instead, you must replace it with a new one so your APC battery backup can continue charging.

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#5 End of Service Life

What it is: All APC battery backups have a limited lifespan, typically between 3 and 5 years. Some batteries might last longer, though the ones discharged and recharged often will wear out sooner.

How it failed: The final reason your APC battery backup isn’t charging is that the unit has reached the end of its service life. 

As the backup battery ages, its internal chemical reactions will stop functioning correctly. That will lead to the battery failing to charge and store power to be used during a power outage.

How to fix it: Unfortunately, the only solution here is to replace the battery in your APC unit. Ideally, you should replace the battery as it approaches the end of its service life to ensure it works during a power outage.

Replacing the battery is a straightforward process. First, you’ll have to open the casing to remove the existing battery before connecting the new one the same way.

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Frequently Asked Questions (FAQs)

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

How Long Does An APC Battery Backup Last?

An APC battery backup typically lasts from 3-5 years. However, the expected lifespan will differ between battery models. Check the user manual to understand your model’s service life so you can replace it before it fails entirely.

Can A UPS Power A Wifi Router?

Yes, you can plug many devices into your UPS through its power outlets. But, then, suppose a power outage ever occurs. In that case, the UPS battery will continue powering those connected devices so that you can continue to use them normally.

How Does An APC Battery Backup Work?

An APC unit works by continually charging the backup battery inside. It connects to a wall socket on one end to receive incoming electrical power. Then you can connect other devices to the unit through its power outlets. Should there be a power outage, the backup battery will continue powering the devices.

Read: Can Roomba Have Two Home Bases?

Which Battery Does APC Use?

According to APC, they use Valve Regulated Lead Acid (VRLA) batteries. They use the same battery type on all their single-phase UPS battery systems.

Can I Use My APC Without Battery?

Yes, you can use your APC without a battery. As long as the unit is plugged into a working wall socket, you can continue to power your devices by plugging them into the unit’s power outlet. However, the APC cannot power your devices during a power outage without a battery.