Suggestion and a maintenance question

I purchased a EcoFlow 3 Ultra about 6 months ago. Everything works great. The only wish I have is there is a way to expand the battery bank to enhance the storage capacity. I understand the product is not intended to be expanded. However, this information was not identifying during my search through most of the AI tools. I wish there is a way to change it. Other than that this device has been working fine, and has able to provide power to my refrigerator for over 10 hours and with spare. With the recent power outage we have experienced, this unit has become our lifesaver during two occurrences. It has been a great investment. I also made it a point to recycle the stored battery backup every two months. Now the question is, is it necessary? Or should I continue to do that every two months?