Power Out

We have power outages everyday for a few hours multiple times a day. Normally it's not a problem. We just go through out our day and it comes back on. We also have a backup battery that we can run some fans and lights. Every once in a while for some reason the power will go out for a long period of time. Last night was one of those nights. It was out most of yesterday then came on for a few hours then was out for over 15 hours. The battery didn't have enough time to fully recharge so this morning it died completely and so did the one fan that was running. It was out for about 10 mins and the power came back on. We were so thankful when it came back on cause 110F or 42C is too hot out to just have one or no fan running.