You need to install a second car battery to keep your power tool running. The longer the DC cables to the battery, the better. I have measured a DC draw of 150 amps with a 1/2 horsepower 10 amp or 1200 watt non-clog submersible pump. Starter repair shops in the Central Florida area can build a powerful alternator for about $80. With these additions to the vehicle, it works great on construction sites. This inverter is designed for use in multi-battery off-grid solar systems. The more batteries the better. Search YouTube for videos of continuous work for more than 6 months with an average download of 50%. It runs on AC power and a refrigerator with multiple batteries attached.