I'm loging data with MicroPython REPL prompt. 

2017-10-30 22:24:43 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
017-10-30 22:28:14 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-30 22:37:07 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-30 22:44:56 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-30 22:53:51 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-30 23:12:39 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-30 23:20:20 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-30 23:27:02 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-31 00:00:04 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-31 00:48:16 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-31 10:47:06 ets Jan  8 2013,rst cause:1, boot mode:(3,0)
2017-10-31 10:53:40 ets Jan  8 2013,rst cause:1, boot mode:(3,0)
2017-10-31 11:01:31 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-31 11:12:33 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-31 11:16:01 ets Jan  8 2013,rst cause:4, boot mode:(3,0)
2017-10-31 11:23:41 ets Jan  8 2013,rst cause:4, boot mode:(3,0)

Writed python script to figure out problem, it seems that watchdog timer reset ESP board.  Trying to increase wdt timeot. Link

from machine import WDT
wdt = WDT(timeout=2000)  # enable it with a timeout of 2s
wdt.feed()