I agree but for first level I use the test light.
I have had circuits show ok on a volt meter, but did not light the bulb in the test light.. I've had 'em light an LED but not the incandascent bulb in the test light.
I've never had to go the 100 watt route.. but I have one in case I do
100 watt test lights...
You can get a 12 volt version of a trouble light or drop light as they used to be called.. Or you can make one by taking a common 120 volt unit and cutting the plug off and wiring battery clips on.. Replace the bulb with a 12 volt screw in rough service (75 or 100 watt sizes are common in RV and Automotive stores, some hardwares) and you have a nice 12 volt high load test light.
I have one that is bigger too.