OT auto/air power adaptors for laptop

My travel trailer runs off solar panels ... I almost never have to use the
generator any more G

I have an inverter, BUT, it comes with the proviso that it doesn't always
work well with equipment that uses wall warts ... in other words, apparently
changing from 12volt to 120volt ( inverter ) then back to 9volt ( whatever )
via a wall wart for charging a cell phone or running a laptop is too much
voltage changing to work well. My experience confirms this and I got a car
charger for my cell phone.


ANYway, I'm thinking of trying to find a way to run my new laptop "directly"
off a 12volt plugin in the trailer and I see some "air/auto power adaptors"
advertised ... for not too cheap .... anyone tried/ using same and can
report on effectiveness?