I've been running my U800 for several years now and have just recently come up against a situation that I don't fully understand.
My station is fully solar powered in a remote location and feeds into the APRS system. I had just "blindly" followed the initial instructions and installed the 9 volt battery which claims is for backup purposes.
I am now questioning the need for the 9 volt battery due to the nature of being solar powered...it never experiences power failures except roughly every 3 years when the 18ah battery that is fed by the solar panels dies and slowly drops below proper voltage. I just replace the 18ah battery and I'm good for another 3 years or so.
I have been dutifully replacing the 9 volt battery roughly every 3 months...a real pain given the long drive required to reach this remote location. The symptom when the 9 volt battery dies is that no serial data is delivered to the external APRS device. I do not make any console changes as far as settings for the local display (time, etc) because I depend on custom software for decoding on my end and of course the APRS system reads the real-time timestamps. In other words...if the main 12 volt system fails for a while (due to inadequate solar charging-very unusual) the U800 bounces right back as soon as adequate 12 volts reappears. Documentation suggests that the 9 volt battery holds the system settings for as long as 24 hours. Actual failures in my environment are likely to last for as much as a week or more, so the 9 volt battery really does not bring anything to the table for me.
I am suspecting that the 9 volt battery drops its voltage so low that it somehow affects the overall circuit of the U800, even though it may be getting a good 12 volt source from the 18ah battery.
1) Does this sound like a possibility? and
2) Given that the whole system is solar powered, do I even need the 9 volt "backup" battery?
3) Anybody have any experience in the Peet systems running with no 9 volt battery? Any issues?
