Short answer is no, short of replacing the inverter. Stock inverter is modified sine wave.
But you’re better off using a DC-DC converter to charge a power station. I’ve been using the Etaker F2000, but there are other choices such as the Etaker F1000/F1000 Pro, Bluetti Charger 1, EcoFlow Alternator Charger (which can now charge any brand), Pecron.
Eviction and other brands also make DC-DC chargers, but most of them are intended for charging an aux 12V or 24V battery from the alternator/starter battery and won’t charge any power station faster than the cigarette plug.
What you want is something that will boost 12V DC to the highest voltage that your power station will accept (typically around 24V for small power stations to over 48V for larger ones). This is what will allow you to charge at faster speeds.
(Power stations typically limit charging at 12V to 8-10A or around 100W, because that’s about all that those cigarette sockets can handle, as you’re experiencing with it getting warm. At 24V, you double the power even if the current stays the same, and at higher voltages, many power stations will charge at higher current, too, as they assume they’re not connected to a cigarette plug. So, for example, 48V might not just be four times faster, but nearly 8 times faster, if the charger and power station both support 800W (like the Etaker F2000 and EcoFlow).
Unfortunately, DC-DC chargers aren’t exactly plug and play, but they’re worth the effort if you don’t mind running some wire.
(Wandering a little off topic below…)
If you’re brave/foolish and have an eTorque, it might be possible to tap into the 48V behind the rear seats, and charge your power station from that. Some might object that that will tax the eTorque generator or battery more, but drawing additional power from the 12V starter battery will do the same thing: the generator first charges the 48V battery pack, then the Ram’s DC-DC charger charges the 12V battery, then your DC-DC charger charges your battery station. This would just cut out two steps.
The biggest potentisl issue with this is that it would likely drain the 48V battery by continuing to charge your power station when the truck isn’t running. So you’d need to use a relay, tied to the ignition signal, to stop charging when the truck is not running.
If it sounds like I’ve contemplated this idea myself, it’s because I have. I haven’t attempted it yet, and probably won’t.
