First tell us what you are powering .. For loads under 100 watts, a one-piece inverter works fine, this is a ciggy-plug (12 volt accessory plug for the political correct) and inverter in one.. I have one in my computer bag.. Now it's an MSW so it may not play nice with SOME chargers, but it works ok with my phones, and my computers and everything else I have used it with.
now understand the phone charger is only about 10 bucks, so if it fails, It fails, who cares.
An alternative is for many things, Most I-stuff, Most Android stuff, you can get a direct 12 volt to "USB" adapters.. I got one at big lots (Again 10 bucks) looks like the letter Y, delivers up to 2 amps, split between the two arms of the Y (The body is the plug) at USB power levels, Feeds my Phone and my Tablet, or my Phone and my Blue Tooth speaker,
Laptop computers often need higher voltages, Like 17 or 19,,, Well There are universal 12 volt power supplies, basically DC/DC converters.. I have two of those lying about somewhere too.. Never used one on THIS computer but do on my other one from time to time.
IGo is one of the companies that makes them, TARGUS and I think Radio Shack is the name on mine.
IF you want to go the inverter route and are worried about MSW messing up your "Delecate electroincs" Well there are some TSW's in teh 150-400 watt range, Now I'd prefer to direct connect with at least 10Ga wire (To the batteries) and a proper fuse, but at low loads they might work off the 12 volt outlet.
