APC backups trip even though have photovoltaic home battery backup

[TreeLady]

I have a home office with 3 Back-UPS Pro XS 1500. We installed a rooftop photovoltaic system with two Tesla Powerwall batteries about a year ago, so we still have power when there's a power outage on the grid. The system has an inverter that converts the DC power from the Powerwall batteries to AC before it comes into the house. However, the Back-UPS still trip, go onto battery, and beep even though the refrigerator and other electrical devices work fine. Why? And is there anything that I can do to stop this behavior other than not using the Back-UPS at all?

[TreeLady]

I think I found the answer as explained in this post: https://teslamotorsclub.com/tmc/threads/powerwall-2-ups-connundrum-and-solution.130085/#:~:text=The%....  

In summary - because it was daytime, and my photovoltaic panels were still producing electricity while my Powerwall batteries were fully charged, the system was sending 65 Hz power into our home. Back-UPS Pro XS 1500 have a "good" electricity range of 60 Hz +/- 3 Hz, so max of 63 Hz. Therefore, the Back-UPS reacted to the "bad" electricity coming into the house as though we had no electricity. 

Looks like it's time to upgrade to some new backups that can tolerate a wider range of AC frequencies.

[JonPro]

Hello @TreeLady.  You may want to look at the SmartUPS Online UPSs and contact the local technical support team of your country.

[TreeLady]

Aloha @JonPro,

I appreciate the comment but I don't see much point in contacting support. I checked the specs for the UPS device, and the hertz produced by my photovoltaic system with battery storage is outside the range of tolerance for the APC UPS. I've tried looking through APC's new product line, but they all have the same hertz range so there's not much point in upgrading. The UPS's from other manufacturers don't meet the loads that I'm running or they have the same hertz range as APC, so it looks like keep what I have. I will still have to shut down my office whenever there's a power outage. I can continue to work on my laptop when it's on battery, but I won't be able to print.

[JonPro]

You're welcome @TreeLady