I know max solar input is 200 watts, but what is the allowable max input voltage? can I tie 2 100 watt panels in series and still be ok with voltage?
Since the maximum PV input is 28 volts as stated above, two panels would be over the voltage limits. You can however connect to panels in parallel and the limiting factor would be the voltage of your panel(s) output x 8 amps.
Ok because im using Renogy 12v 100 watt panels,their specs say they have an optimum operating V of17.9V and open circuit V of 21.6V, so i will combine them in parallel as you suggested, thnx for your response, ps i also purchased the AC180 a few days ago and im really impressed with it.