As said, you need a pure sine
inverter to charge a toothbrush. Or a Canon camera
battery charger. Modified sine blows them up instantly. (not literally, they just die). Very tedious.
I do have a universal 12V to 19V thing for my laptop (actually it's adjustable for voltage and has plugs for every type of laptop socket.) from Aldi but it kicks out so much EMC that you can't use the radio or the telly when it's on.
Having had bad experiences with 12V-USB plugs, the sort that plug into a cigarette lighter socket, or built into a panel, I now only use the mains charger supplied with the device. My devices have the latest high speed charging which basic USB outlets don't support.
Which is why I use a 300W pure sine
inverter for everything. It will even power the slow cooker as I drive along, about 125 W. It sits in the sink with a bungee over the lid. Hot meal ready at the end of the day. It came with a cigarette lighter plug as well as a cable to hardwire. Don't even think of using the lighter socket cable, that would only be suitable for very light duty. My ducato has an (I think) 18A outlet but it blew the
fuse for that straight away.
I'd say 300W is about right for light duty, I wouldn't want to run it continuously at 300W despite supposedly being rated for it. Yes obviously they take a lot of current if run at full rating, but if you are not doing that they take much less. You do have to remember to turn them off when not in use, they take a steady drain of maybe 0.5A even with no load. The bigger the
inverter the bigger this drain. Bigger is not always better.