There is a new crop of AirPrint printers from the major companies, but I haven't looked to see if any are portable. One option is to use a DC-to-AC inverter in your vehicle to power one of the non-portable AirPrint printers.
By setting up the printer's WiFi to host an Ad Hoc network, you can print directly to it without having a separate WiFi router.
Nope---amazingly enough, not a one. There is a fairly substantial list of Airprint capable printers out there mainly by HP & including Epson, Canon etc. but they're almost all all-in-one behemoths....
Basically they're using Airprint dedicated printers as a way to move older, bulkier technology.
Nothing's sillier than carrying around one of these elephants with a slim moblie device like the iPad.
There is a solution ... I've been happily printing for a while from my iPad to my battery-operated HP H470 with absolutely no wires (and no router / pre-existing WiFi connection - it operates in AdHoc mode). Literally just the iPad and the H470 - in fact, one time in a marquee in the middle of a muddy field with no power and a long way from the nearest WiFi connection, so it can be done from literally anywhere.
I also couldn't find any info on a true mobile printing solution for iPad (or iPhone/iPod for that matter) but felt sure it must be possible, somehow - so once I'd sorted it all out, I wrote down the solution and the steps to get it to work in the hope of helping others:
Hope that's helpful!
I found a way to set up a mobile printer to work with iPad, but it requires you have an iPad with the mobile hotspot feature. I've created a parts list and a youtube video to help you get it set up. They can be found here:
I found a working solution.http://www.brothermall.com/Mobile-Printers/Model/PJ673/Overview. Brother has a mobile printer only for the ipad that prints over adhoc. They sell car adapters and ac adapter for any situation. Since it just came out there is not many videos about it and it has a $500 price tag. This is a video for the previous cheaper model https://www.youtube.com/watch?v=gQwoxpDD6dI and how it works. And I also found another video of the actual 673 (ipad model) https://www.youtube.com/watch?v=KVp77vT3VaU. The brother website says an app must be used to make prints. I have just emailed the company now to see if the printer is compatible with embedded print options on other apps.