fixing power limit display

[discip]

@Ralim

Since the first digit was cut off, the displayed value was misleading unless one was careful to notice that the scrollbar didn't blink after 95 was reached.

Not sure if this solution is correct as the Pinecil V2 side says max 88W.
But after seeing the wiki I'm even more confused as there are several different statements about the maximum wattage allowed. Also, the current MAX_POWER_LIMIT is 220.

Do we need to lower the MAX_POWER_LIMIT or should this fix be implemented?

[River-Mochi]

Pinecil says 88W as "safe" number from the manufacturer but can theoretically go to about 120w.
I have personally pushed it to 110W in extreme testing - we need at least 3 digits for pinecil V2. which is why I had old ticket that Ralim fixed which was when V2 kept resetting as soon as I hit 99.9W it would reset to 0W. Ralim fixed that a while ago specifically because V2 can do 3 digits of watts.

TL;DR manufacturer will only support it at 24V max, which is the 88W as they are also worried about people using more than 24V on the DC barrel jack; unofficially, it supports PD3.1 usb-C chargers to 28V
ohm calculator will show ~126w theoretical max at 28v, 6.2ohm tip. in reality we can't ever get 126w but we can get close.

they base the 88W on 24V max and a 6.5 ohm Tip resistance (again to be conservative from manufacturer so that people don't complain).

in reality most of the tips are 6.2 ohms. 24v , 6.2ohms = theoretical max of ~93w
6.5 ohm , 24v = 88w (printed on the side to be conservative. head of Pine64 confirmed this )

In reality, we have been testing Pinecil V2 for over 7 months now with special EPR PD3.1 chargers at 28V which gives Theoretical max of 126V. my testing with PD3.1 28V , I'm only getting about 110W because V2 goes from cold to 320C so fast 2-3 seconds that it never gets chance to do more than the 110W I've pushed it to using special test methods.

with a DC barrel charger (dumb brick type - no smart chips/negotiation, then people should stay at 24V or less) but PD3.1 EPR 28V 140W , 5amp chargers so far have been good with Pinecil V2, and have not killed it and do 3 digits of watts power.

[discip]

@Ralim
Sorry to bring this up again, but I don't quite get why the MAX_POWER_LIMIT is 220.
Shouldn't that be something like 140 according to #1641 (comment)?

[River-Mochi]

maybe it was typo for 120w? 220w is a lot.

220w would theoretically need 37V, 6 amps. PD3.1 epr future will be 5amps, 36V then 5amps 48V.
Based on 6.2 ohm tip, it's not a doable number for PD3.1
(based on 8.0 ohm tip we need 42V to get to 220W).