im getting ready to head to disney world next weekend and I will be plugging up a tv and DVD player. Has anyone used an inverter that plugs into the cig lighter with any luck and what wattage was used? Thanks

 

The cigarette lighter is not designed for long term high current use. Allowing for losses in the inverter if it is on a 10amp circuit 100 watts is effectively the maximum, 150 watts for a 15 amp circuit. Unless it is a very small TV you will likely be pulling too much current.

You would be better off running a separate line to a battery and use that to power the inverter. Be sure an put an in line fuse as close to the battery as you can. A fuse on just the positive line should provide adequate protection but I personally like to fuse both the positive and negative lines. Run the negative line to the battery, not to the frame.

For a moderate safety margin take the total wattage needed and divide by 10. This will give you the current load assuming 90% efficiency on the inverter and a 10% safety factor. Personally I like to divide by 8 for a higher safety margin and to minimize any voltage drop but others may consider this overkill. You will want your fuse(s) to be for this rate and you can search online for what gauge wire you need for the calculated current. Be sure you purchase pure copper wire. Some stereo suppliers sell wire that is only copper on the outside. Personally I just use the wire from Lowes/Home Depot. Welding cable is technically a better choice due to the flexibility but tends not to be available just around the corner/on weekends.

Probably a lot more information than you were expecting but a lot of people are too blasé about this and it can be a safety issue. You have a vehicle that can last for decades. Best to do things right.

Edit: PS - Keep in mind also that a starter battery is not the best choice for long term drains. You don't want to be out in the woods and then discover you can't start the truck afterwards. Consider running things off a separate battery in that case. Although consumer boating/"deep cycle" batteries aren't really deep cycle they are a lot cheaper than true deep cycle batteries and should have the amp/hour capacity for several hours of viewing and you don't need to run wires through the firewall, etc.