Problem- CCR 1036 12G-4S

Hi,
Yesterday an unexpected error occurred with my routerboard 1036. I am powering it form 24v dc from two batteries, it had been working for about one week, but yesterday I connected it to the internet and after about two hours it stopped working at all. I tried to power it but no led work, and it doesn’t start at all.
So I don’t know what is the problem.
Isn’t there a protection circuit for voltage? Does connecting the routerboard directly to batteries damage it?
Could be the problem a software problem, because this problem came after I connected the internet? (someone said that the routerboard could upgrade itself and locked!!!)
I am waiting your help> Thanks.