beaglebone green wireless is shutdown

Hello folks

My name is Felipe and I looking for solution or some hint to my newest problem.
I got a BBGW running BeagleBoard.org Debian Image 2016-11-06. My project is get many measurements from differents sensors like conductivity, dissolved oxygen, and others. and put this values into web server using mobile broadband. The problem is that system is shuting down. I looking in log files I don’t get many information. the most relevant information that i got is in /var/log/auth.log and says.

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Feb 9 11:06:01 beaglebone CRON[1050]: pam_unix(cron:session): session opened for user root by (uid=0)
Feb 9 11:06:03 beaglebone CRON[1050]: pam_unix(cron:session): session closed for user root
Feb 9 11:07:33 beaglebone login[574]: pam_unix(login:auth): check pass; user unknown
Feb 9 11:07:33 beaglebone login[574]: pam_unix(login:auth): authentication failure; logname=LOGIN uid=0 euid=0 tty=/dev/ttyGS0 ruser= rhost=
Feb 9 11:07:36 beaglebone login[574]: FAILED LOGIN (1) on ‘/dev/ttyGS0’ FOR ‘UNKNOWN’, Authentication failure
Feb 9 11:08:01 beaglebone sshd[1107]: Accepted password for debian from 192.168.7.1 port 37207 ssh2
Feb 9 11:09:01 beaglebone CRON[1153]: pam_unix(cron:session): session opened for user root by (uid=0)
Feb 9 11:09:03 beaglebone CRON[1153]: pam_unix(cron:session): session closed for user root
Feb 9 11:09:23 beaglebone systemd-logind[357]: Power key pressed.
Feb 9 11:09:23 beaglebone systemd-logind[357]: Powering Off…
Feb 9 11:09:23 beaglebone systemd-logind[357]: System is powering down.
`

my system have a beaglebone green wireless, 1 PCB that feed beaglebone from charger controller that connect to battery and power supply.

Thanks for your attention
Regards
Felipe