The following information is for someone who would be interested in getting a better PD Charger for the GPD P2 Max with higher wattage of power output, since the supplied PD Charger only delivers a maximum output of 18W.
Question asked on IGG:
What is the Maximum PD power input can the laptop receive, charge and withstand. I was planning to get a Anker Atom PD Gallium nitride (GaN) charger which pumps following outputs:
5V ⎓ 3A
9V ⎓ 3A
15V ⎓ 2A
20V ⎓ 1.5A
Here is what GPD says:
This is also possible, the motherboard of P2 Max limits the maximum input current to 2.1A, but there is no limit voltage, and the maximum voltage supported by the PD protocol is 20V, so theoretically the maximum input power supported by P2 Max is 20V==2.1A ( 42W). However, we do not recommend this because the higher the power, the hotter the battery is. The official standard charging head is limited to 25W, which is 12V==2.1A (25W)
Right @Bluegizmo83 , I just had a moan at @aravind in private bless him saying similar. I’m beginning to get extremely frustrated by false claims made by GPD.
P2Max draws 28W when charging the battery and being used at the same time. Closer to 15w when fully charged - have a battery that gives output details (Goal Zero Sherpa 150 AC) - and another one that couldn’t provide enough usbc jiuce to get it charging
So, I’ve spoken to GPD about the power issue. Regardless of the profile chosen (5V, 9V, 15V or 20V), the current is hard limited at 2.1A. That means if you use a 60W, 20V adapter, it will cap at 2.1A and is safe from GPD’s perspective. It also means that if you use an underpowered adapter (like 12V @ 2.0A), it also assumes the adapter is 2.1A and the P2Max will attempt to consume up to 2.1A regardless of what the adapter or profile can handle. If the device pulls more current than the adapter can handle (aka: anything up to 2.1A), it will cause the device to reset charging (aka: stops accepting power, then starts again). Typically when this happens, it will loop in resets and is probably bad for the device plus it doesn’t really charge during that time.
to;dr - If you want a backup power adapter for the P2Max, any 20V over 2.1A would probably be the easiest to find and safe due to GPD’s hard limit on current.