power inverter recommendation

Trying to find reviews of power inverters on the commercialized web has driven me completely nuts. The bottom line question is, what setup will actually work for my Dell Inspiron 1720 with 17" screen and NVIDIA 8600M GT video card?

The laptop will be used while camping with the car not running. I just installed an Odyssey deep cycle battery so I'm not worried about killing my car's battery. I am worried about how many watts I can pull through the cigar lighter and what's actually enough to run the laptop.

The cigar lighter wiring is 18 gauge AWG wire and is protected by a 20A fuse. The only other devices in this circuit are some interior car lights which shouldn't be drawing much power. I figure I can get away with a 15A pull easily. Any reason I'd be wrong? 200W continuous power seems to be the theoretical maximum of what I could safely pull through the plug.

The car is old, a 1984 Chevy Citation II V6. Consequently, the cigar lighter is next to the ashtray and I can't put a big fat inverter in the plug. It has to be something with a skinny plug and a short wire attached to it. Either that or a slim "pistol neck" plug, like I have for my cell phone charger.

I have a 3rd party 90W output AC brick (original Dell fried) with the following specs. Input 100-240V~2A 50/60Hz. Output 19.5V .-.-. 4.62A. An original Dell brick specifies 1.5A input, not 2A. I am concerned that this brick could be inefficient and may draw as much as 100V * 2A = 200W. Other possibility is this is only a max rated load, so surge power would be ok. Anyone know for sure?

I plan to also use an AGPTek external battery charger, although I haven't bought one yet. The problem is my laptop DC input appears to have fried, it won't recognize adapters as Dell-specific anymore and the battery won't charge. Why and what to do is a subject for another thread. Here, I'll ask is there any reason a modified sine wave would hurt my battery when using an AGPTek external charger? Read some gloom and doom about "batteries" and MSWs somewhere but I don't know what to believe.

Problems I keep running into:
- often "200W" inverters don't provide 200W continuous power, it's just slimy marketing
- reports of noisy inverters. That would be annoying.
- inverters that are junk or damage circuits
- inverters that just don't have any reviews

Help! Someone tell me a solution that they know works and is reliable. Also, you do play 3D games on your laptop, right? I want something that works with a "for real" load.

 

Well I couldn't wait any longer for advice, so I pulled the trigger on a Wagan 2402 Smart AC 200 USB. It was the only continuous 200W unit on Amazon that nobody seemed to have a horrible snarky complaint about. Hope I picked well, as I've never heard of Wagan before, or most of the other power inverter makers actually. It's all coming from China nowadays regardless of name brand so who knows. Black & Decker didn't get a good review, and Duracell wasn't actually 200W continuous.

I also bought the AGPTek charger, based on the only review I could find that said it worked for some Inspiron somewhere. Hope it works for mine.