Will it cause an issue if I hook up a 800 watt inverter to the 12 volt battery so I can use a drill or other small power tool ? This is on a 2010 Prius.
You will be drawing around 70 Amps from the battery/12V system. There is a 100 or 150 Amp fuse in line with the inverter/charger, but if your battery is good most of the current will come from it. If the car isn't running (I don't recommend running it that way) all current will come from the battery and the fuse won't be impacted. I don't recommend running it that way because in roughly 30 min of use at full power the battery will be fully discharged. DO make sure you use heavy leads to the battery terminals - #6 or larger wire finely stranded. DO make sure you scuff off the oxide on the terminals before you bolt down the connections. DO make sure you use zip ties to keep the cable from rubbing on things as the car goes down a rough road.
