APC smart ups 1500 battery replacement hot swap

I love my APC 1500 smart UPS. It gives me confidence that my home computers are protected from power spikes and brownouts in my area. But as with all devices that have an internal Lead Acid or AGM battery, they will require replacement after 3-5 years. This is normal.

Just as a car battery these internal APC UPS batteries are kept in a condition that is not ideal. They are often kept at a fully charged state and then driven very low when there is a blackout. Often the charging circuit creates heat which makes the batteries hot over time.

The one great thing about the APC Smart-UPS 1500 battery replacement is that it is hot swap. This means that the power can be left on while you replace the battery.

Which Battery for APC 1500 Smart-UPS use?

The APC 1500 smart uninterruptable power supply uses two internal AGM 12v – 18 amp hour batteries connected in series. This battery bank is called an APC RBC7 Battery Pack.

These batteries are very popular for their high capacity and small form factor. They are often found in high-performance jump starters for semi-truck trailers and uninterruptable power supplies (UPS) such as the APC Hot swap UPS.

The cheapest way to replace these batteries is to buy them individually such as the Universal UB12180 12v Battery. This way you can then make up your own RBC7 pack by reusing the Anderson plug and the 100 amp fuse from the old RBC7 battery pack. This will save you around $100 for only a few minutes of work.

Product Specifications for Replacement RBC7 Battery Pack – 24 Volt, 18 Ah Battery with SB 50 Anderson plug.


The above APC Smart UPS 1500 battery replacement hot swap easy. You don’t even have to turn off the power.

APC back ups pro 1500 battery replacement procedure.

apc back ups pro 1500 battery replacement

Start by shutting down your UPS, computer, and disconnecting the power supply to the APC 1.5KVA Pro Smart-UPS. You can also hot swap for always-on computer gear.

  • Remove the front cover by prising it off with a large flat screwdriver.
  • Place the cover on the top of the APC UPS. Be careful as there is a small ribbon cable connect the front display.
  • USe a Philips screwdriver to remove the 2 screws on the top hinge plate.
how to replace the battery in APC 1500 smart ups yourself remove front cover
  • Pull down this plate and unhinge it from the bottom.
  • Pull the RBC7 APC battery bank out of the frame. If your batteries are old and have swelled up this may be difficult.
battery for apc 1500 smart ups
  • Unplug the 50 Amp Anderson connection plug.
  • Use a Philips screwdriver to remove the 4 screws holding in the fuse and the Anderson plug into the APC RBC7 battery bank. Keep these as we will reuse them.
remove Anderson 50 amp plug from RBC7 battery
  • Fully charge the new 12v 18ah batteries individually using a quality multi-step charger before placing them inside the UPS. I use a Ctek 5 battery charger.
  • Bolt the new 12v batteries together along with the fuse and Anderson plug. This will make a new RBC7 battery pack. It is best to use double-sided tape between each battery. This will help keep the batteries together as a block.
DIY battery for apc 1500 smart ups
  • Test the new battery bank to make sure you are getting 24v at the Anderson plug connection. If you are only getting 12v you have wired up the battery bank in parallel and this is wrong. These batteries must be wired up in series.
  • Reuse the black protective terminal covers. you can stick these down with double-sided tape or some hot glue.
reuse battery termainal covers from old rbc7 battery pack
  • Plug in the Anderson plug and push the battery back into the APC 1500 Smart-UPS case.
  • Place back the metal hinge and screw it back up
  • Carefully push on the front power indication cover and tap it closed.
  • Plug the APC 1500 Smart-0UPS into a wall outlet and test for correct operation.

The low battery alarm should now be gone and the full battery indicator lights will be shown close to 100% full.

APC UPS beeping with red light

If your APC UPS is beeping with a flashing red light this usually means there is a problem with the power somehow. Often this is just a loss of mains power so check your fuse box for a tripped breaker or fuse.

You will also see your mains power indicator got out or turn red on the UPS. Sometimes a higher or very low mains input voltage will trigger an alarm as well.

If the battery indicator is flashing and it is beeping once every 3 seconds this usually means that the internal battery has failed. As there are 2 internal batteries connected in series it only takes one battery to fail for the alarm to show up. This will also be accompanied by low battery reserve power.

It is best to replace the internal battery after 3 years as a preventative measure. This is because the internal battery will be very degraded after this period, and your run time without mains power will be less.

Why is my UPS beeping

Apart from a power loss your UPS could be beeping due to a bad battery. If the UPS senses a low battery voltage you could have a battery that is failing. Replace the battery to clear the fault.

A high power load could also cause the UPS to start beeping. Be sure to stick to appliance’s that are rated for use with your UPS.

For more Beeping codes and error faults check out APC website.

Is it safe to run a UPS with a dead battery?

I will say No! Often the UPS will detect the failed battery and will disconnect it from the charging circuit. You won’t have any backup power and if the UPS did try to switch over in a brownout or blackout event your computer will still crash.

Continually charging a shorted out battery will create extra heat and could cause a fire. Be safe and replace your USP battery every 3 years.

12v Lead acid and AGM also known as Absorbed Glass Mat have a use-by date which decreases with use and is subject to heat. Continually charging and discharging your battery fully will decrease its life especially if your fully deplete the battery which is not recommended.

Once your APC back ups pro 1500 battery needs replacement, then it is best to unplug it until you are able to replace the battery. It will be safer than having a UPS with a bad battery.

Does my APC Smart-UPS have “Hot Swap” Batteries?

APC UPS hot swap battery

Some people and businesses can’t afford downtime on their PC. This could be because of a web server or a computer controlling an important piece of hardware. A great solution is the ability to change out the battery online. This is called Hot Swap.

All Smart-UPS models, with user-replaceable hot swap batteries, will have part numbers starting with SU, SUA, SMC, SC, SMX, SMT, SURT, SRT, and SRC. Check the rear of your power supply for the model numbers.

My APC smart ups 1500 battery replacement is hot-swappable, but due to the battery swelling up I had to disconnect the power.

The procedure to replace these batteries will be dependent on the model number. But it will be safe to pull out the battery bank online and plug in a new fresh battery pack.

If you have any difficulty removing on older RBC7 battery due to it swelling up you will need to use some brute force. It will take some extra pulling power to get it out. Otherwise, the whole APC UPS top cover will need to be removed. This is why the power must be removed to the UPS.

Problems you may face replacing your UPS battery

Occasionally you may run into some problems replacing your internal UPS batteries. The biggest issue I have faced is if the 12v battery is very old it may begin to swell and deform the storage case

This makes it very hard to pull out these batteries. The best way I have found is to place a towel or pillow on the floor and gently shake the UPS batteries out. This can be difficult due to the weight of the combined UPS and batteries.

If this fails you will have to completely strip down the sides and top cover of the computer UPS. If you stick with the 3-5 years preventative maintenance of your UPS batteries you will have no problems.

Conclusion – APC Smart UPS 1500 battery replacement hot swap

Many people think that once the UPS internal alarm starts that the UPS is dead and can’t be reused. This is false and may only require 1/2 hour of your time to replace the internal batteries.

All uninterruptable power supply batteries can be replaced. With the advancement in AGM battery technology often you can get higher amp ratings so your UPS will last longer without power.

My original APC 1500 smart UPS is on its 3rd battery pack in 10 years. This UPS is a workhorse and is never turned off. I’m very happy with APC and the included monitoring software. Stick with brand-name computer UPS hardware and it will last a lifetime.

The hot swap capability means anyone can do it with only a Philips Screwdriver and some time. If you make up your own RBC7 battery pack then the cost is even further reduced.

Be safe and feel confident that APC is protecting your expensive computer gear.

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