Can I convert it to 12vdc or 110AC directly without battery?
I do not know the answer. I have used this charged just once so far. It is packed away with my Camping stuff but I also believe I did have it plugged in and turned on even before battery was charging and it worked. I tried looking up your question here online as well quickly, but to no avail. Sorry for delay I was finally checking e-mails as saw this question now. Got to go, Not sure if helpful but I tried!! Take care.
I dont know you will have to call the manufacturer.