Inverters for in-car X-box

Hi,

I am installing an Xbox in my 350z and splicing into the car's stock navigational sreen.  I have previously installed an aftemarkerket audio system consisting of a pre-amp alpine head unit, two JL audio amps (each with sepearate fused 8 gauge leads from the battery.

Anyway, I bought a monster power 150watt inverter for the Xbox...

http://www.monstercable.com/caraudio2/productPageCar.asp?pin=1921

I bought this and paid the higher price because of reviews on power conditioning and overload protection, etc.  Xbox is supposed to consume 110watts so I figured 150w would be sufficient since Xbox is only AC device plugged into inverter.   anyway with the engine off, inverter on, and Xbox off,  the invertert's 12v indicator light is yellow. per manual, yellow means the inverter is either under-powered or overpowered (I would guess underpower).  In this same state, if I turn the Xbox on, the protection light comes on and the alarm sounds either intermintantly or constantly.

With the engine on, inverter on, and xbox off, the 150w inverter's 12v indicator light is green (meaning all is OK).  If I turn the Xbox on, everything is still fine.

So, the issue is that I would like to use the xbox for reasonable spans of time with the engine off (in a parking lot, etc.)  If I buy a bigger inverter, will this solve my problem, or is the problem rooted in the battery's limited charge and there is no possible way with the current battery to use the Xbox with the engine off?

Here is the bigger Monster iverter (300w).  I would not be very easy to test any theories with this since it requires hard wire installation with 8gauge wire as opposed the 150w which gets spliced right into the lighter adapter.

http://www.monstercable.com/caraudio2/productPageCar.asp?pin=2720

I also looked at much cheaper inverters at Bestbuy, but would be leary about use without fuse protection for my xbox.  Any advice from those with experience on this is appreciated in advance!

JC

Thank  you very much for info.. so yes I did have it splice into lighter adapter and yes it is about 18gauge wire.

As I mentioned, I have two 8 gauge leads already coming back from the battery to each of my JL audio amps.  Once of the amps is a 250watt x 1channel powering two 8" JL w3 v2 subs and the other amp is a 300wx4ch powering all of my mids and tweets.

I would rather not pull everything apart to run yet another lead from the battery and would instead like to use a distribution block to take one of 8 gauge the JL amp leads and split it into an 8gauge to the amp and a 12gauge to the inverter.  But, I have read the the most common setup for a distribution block is a 4gauge run from the battery split to two 8gauge leads.

1. Since my amps (45amps or so continuous) are relatively small and the inverter only consumes 30 amps, would I be OK using a distribution block to split the 8gauge amp lead into an 8gauge and a 12 gauge  to the inverter?

2. Which amp lead would you use (the 250w single woofer amp or the 300w amp?)

3. Which inverter would you use (the 150w inverter or the 300w inverter?) also, keep in mind that the direct runs from the battery are obviously not switched and the 150w inverter has no remote capabilities so I would manually have to turn it on and off (pain in the a$$).  But the 300w inverter has a remote function that I could splice the remote wire to my amps in order to turn the inverter on and off with the amps.  But I don't want to use the 300w inverter if it is just going to sap more juice from my battery which is why I asked if the inverter consumes based on its rating (150 vs. 300) or based on what's hooked up to it?

Thanks again in advance for any info.

JC