Being a fresh ground coffee drinker i got to have my coffee bean grinder handy.
My MR COFFEE grinder will just barely run (hit or miss) on a 300WATT PSW Inverter. The inrush kills it... Runs great on a 400WATT MSW mdl I have in my truck.. I started at 150W went to the 300W and then finally ended up with the AIMS 600WATT PSW Inverter. I got mine from AMAZON for $149 5-6 years ago.
Having only one GP27 battery will hamper alot of INVERTER use. Two 6VDC golf cart batteries (225AHs) in series will be a great deal for you...
I'm running my 255AH capacity battery bank now and do almost everything we do at regular camp grounds except air cinditioning and high wattage microwave use. My 255AH capacity holds me up to around 12.0VDC the next morning when i re-charge using my 2KW Honda generator for a three hour run. I now use the Cuisinart Grind and Brew coffee maker and make my coffee for the day when I am running my 2KW Honda Generator re-charging my battery bank at 8AM each morning. The Cuisinart only takes 5 minutes to brew a pot of coffee into the thermos carafe... Stays hot all day long
Roy Ken