Hello all from a newbie to this forum, and even to laptops! I just ordered an Amstron NDC-40 car ADAPTER (DC TO DC) for my newly acquired Dell Inspiron 8200 because I grew frustrated by the costs, and unreliability of the Li On batteries, as I'm sure others have. I'm really not using the laptop for the car, but I have TONS of 12V lead acid battery packs (10 amp) that I used to use for portable video lighting, so I figured I'll use THOSE. I was going back and forth with a friend about the old INVERTER vs ADAPTER issue, and I FINALLY figured I made the right decision, re affirmed by info on the FAQ section of mp3car.com! I didn't get the adapter yet, but I'll keep you posted on how it works. I'm GUESSING I should get 2 hours out of my 10 amp lead acids, since the Inspiron wants 4.5 amps @19 volts. If I get close to that, I'll be a happy camper, because you can get those batteries for about $16 each (there's two 6 volt 10 amp batteries in each pouch), and I used to sling these on my shoulder with the strap for my video lights. This doesn't make for the most convenient portable solution (certainly not the LIGHTEST one), but I prefer the lead acid technology over the new Li On, because of the RELIABILITY! Some of these lead acids are as old as 1997, and they're still kicking! I put a "floating charge" on them about once a month. Time will tell if I made the right decision....

Jim