I would recommend the Brinkmann Max Million II rechargeable spotlight, I have one.
I got mine for $40 dollars from Walmart, but you might have to buy it online.
It comes with two batteries that are rechargeable and can be taken out by just pressing two tabs on the side. The batteries can be charged in or out of the spotlight, so you can have a fresh battery ready to pop in when the first one dies, giving it a very long runtime.
It comes with an adaptor to run it directly from the car's 12 volt DC socket (with or without the battery in), but not to charge it.
The Power On Board HID comes with a car charger, but it can't be run directly from the 12 volt DC source.
When the Brinkmann's batteries are fully charged the charger will shut off so you can leave it plugged in all the time or when ever it's not in use, and then if it loses charge over time the charger will turn back on for a few minutes.
It has a 75 watt halogen bulb, and the beam can be adjusted from spot to flood mode. On spot mode it can illuminate a treeline 1/3 of a mile away, and on flood it can light up a large field or the front of a building.
It seems to have a very good runtime, I have used it a lot and it stays at full brightness for a pretty long time. I think it runs for about 20-30 minutes. The Power On Board HID can stay on at full brightness for an hour.
I have the Sam's Club Power On Board HID and it is a very nice light too, and I also recommend it, but there are several things I like better about the Brinkmann.
I could be mistaken but I think the Brinkmann is pretty weather-resistant
It is also very durable, more so than the Power On Board HID and much lighter weight.
IMO the Brinkmann and Power On Board HID are comparable in performance, the HID throws farther and the Brinkmann has a wider beam for better illumination.
The Power On Board HID does put out more lumens than the Brinkmann, so it would be better to light up a large room. The Power On Board HID also has a more intense beam with a much brighter hotspot.
I highly recommend either the Power On Board HID or the Brinkmann Max Million II Qbeam 2 million candlepower rechargeable spotlight.