I’m looking into using my laptop while off-grid in the field operating amateur radio and am trying to figure out a way that I could charge the laptop from my portable power setup. My question is what would be required to charge the Framework 13 from a 12V battery?
Ideally, I would like to modify a normal expansion card slot with Anderson PowerPoles so that I can hook up to the system I already have for my radios. The only thing I’m concerned about is the electronics required to negotiate the correct voltage and current to effectively charge the battery. Are the necessary electronics to negotiate the power and to convert from 12V to the required voltage already in the laptop or will I need an external board?
The simplest solution would be if I only had to hook up a power cable from the battery to the power pins on the USB-C, but I suspect more will be needed to actually charge effectively.
Does anyone have any insights into this that might help me with this project?
Any car charger that plugs into the 12V (cigarette lighter) port and has a USB-C port should work. Of course, check the maximum wattage on it to make sure it is high enough for your laptop, because most are fairly low power for cellphones, but higher-wattage ones do exist (see Anker). You may have to do some disassembling to get it connected.
Get a quality USB-C PD 12v car charger. Choose a wattage that your 12v supply can handle safely, of course.
You can not just connect 12v directly to any USB-C powered laptop.
Normally, all USB ports will be outputting 5v. The laptop switches to charging after it sees and communicates with a USB PD (Power Delivery) controller inside a USB PD power supply. Could you trick the laptop & have it charge ok without a full, proper USB-C PD 12v car charger? Maybe. But there probably isn’t any off-the-shelf solution to try that. You would need skill in building electronics and configuring chips such as USB PD controllers to even attempt it.
Looking at it now, though, the electronics, at least from what their graphics show, probably won’t fit into a Framework expansion port, so this would have to remain external to the laptop. At 167.5W, your 12V battery supply also needs to be capable of ~14A, although if you are definitely not using the full 167W, you can reduce that.