Buying an original APC battery cartridge #7 can cost you a pretty penny. Luckily you have the option of assembling your own RBC7 and replacing it. This DIY approach can actually help you save more than half the cost of purchasing an original replacement.

If you’re worried that the warranty will become void once you start fiddling with the battery, then you need not worry. APC covers the entire unit for 2 years after which it becomes void anyway. If 2 years have passed, then you can start on your project without worries.

You will need:

• Two replacement 12V 18Ah UPS Batteries
• A phillips screwdriver
• Double-sided tape

Step 1. Remove the old battery cartridge from your unit

Make sure to power off the UPS before opening the unit. Pull the front plastic face way from the box and flip it on the top of the UPS. You will see a metal plate, unscrew and remove it.

Step 2. Check the new batteries

Use a digital voltmeter to check the voltage of the batteries. If they show a reading any less than 12.55v then you may have to opt for another one.

Step 3. Remove the plastic covers, fuse and Anderson connector

Remove the two plastic terminal covers found on to of the two 12V 18Ah batteries, they are held by double-sided tape. Once this is done, unscrew the cable with the Anderson connector and the 100A fuse. Make sure not to damage these parts as you will need them when assembling your new RBC7 cartridge.

100A Fuse	Anderson Connector

Step 4. Assembling the new RBC7 battery cartridge

At this point, you need to place the batteries beside each other similar to the way the factory batteries are placed. Use double-sided tape to stick the new batteries together.

Reattach the cable and fuse. Start with the cable, if you install the fuse before the cable, there is a risk of shorting out the battery.

You can now attach the terminal covers using double-sided tape. They add extra protection to the battery terminals.

Step 5. Reassemble your APC UPS

Put the UPS unit back together by reversing everything you did in the first step. When you are done turn on the UPS and leave it unplugged for a couple of minutes in order to make sure it runs on battery power without a problem. Finally, plug in your UPS and leave the new battery cartridge to charge overnight.

If you feel that assembling the batteries may be tiresome for you, then you can always opt for a pre-assembled RBC7 battery cartridge. Click here for pricing.

Step 6. Calibrate

After the batteries have been charged, the next step is to begin the calibration of the UPS. This is done so that the readings on the capacitor and the runtime are accurate. Load the UPS to about 30-50% watt capacity and connect a non-varying load to the UPS. Disconnect external power using a circuit breaker and let it run until the UPS completely shuts down. This step may take up to an hour.

Step 7. Charge Again

Set your UPS charge overnight once again. Your UPS is now ready to use!