Today we had some fairly significant thunderstorms in this area and of course the grid power went off for a few hours. My UPS unit kicked into gear and was holding the station equipment steady, but not for long.
It seams that the UPS batteries are getting pretty weak. At the time of their use today I had only the Davis console, a Raspberry Pi, and the ViaSat modem pulling power from the UPS. I know the satellite modem is a power hog, so I disconnected it from the UPS to preserve the battery life.
After checking with my power company’s website outage map, I could see that the power would probably be off for at least several hours. My UPS showed approximately 180 minutes of reserve and I started worrying that my WeeWX data file might become corrupted if the UPS initiated a quick shutdown. At this point I figured I would just manually shut down the WeeWX software running on the Pi and let the Davis Console logger keep recording weather data in the background. The problem was that I foolishly could not remember the proper Linux command to shut down WeeWX in the console window. I tried several options with nothing working. I had my satellite modem shut down so no internet either. It was at this point that my fears were realized when the UPS suddenly shut down much quicker than expected. Now everything was dead except the Davis Console. Fortunately it has it’s own batteries that are capable of powering the station for several days. At least I was not losing data as the storms were raging outside.
Eventually a few hours later the grid power was restored and I was fortunate that my WeeWX data file was not corrupted during the sudden PI shutdown earlier. I learned a lesson today to have a written plan when something like this occurs. I now have a nice little laminated card with all of the Linux commands needed to safely shut down WeeWX properly and quickly before any potential data corruption. I also need to look into replacing my UPS batteries as they are obviously not up to carrying any load for very long.