(11-20-2020, 11:51 AM)xyzzy Wrote: Anyway, a new PCB rev that will draw more than 3A from the DC barrel connector isn't really viable, since it wouldn't be possible to connect any of the existing power adapters without overloading them. It's not possible to just just "draw less" from the 3A adapter. The charger will try to draw more and the adapter will be unable to keep at 5V and drop voltage, or totally lose regulation, or trip a thermal fuse, or (I see the pine supplied adapter is not UL-listed!) catch fire.
It should be possible to use different size of a power plug connector for the revised PBP board. Or just put some red sticker saying min 4A is necessary. If I would have a choise whether to buy old safe power limited board or 4A capable board with all mentioned risks, I would prefer the latter.
(12-04-2020, 11:10 AM)dsimic Wrote: Once the CPU cores are all kept at 100% utilization for an extended period of time (20+ minutes), the heat soak from the SoC affects the battery charging IC (i.e., TI BQ24171), which goes into thermal shutdown. As a result, battery becomes rapidly discharged because the loaded SoC uses a lot of power and there's atually no charging at the same time. Turning the laptop upside-down and providing additional coolling to the back of the laptop turns the previously mentioned 20 minutes into about an hour, but the BQ24171's inevitable thermal shutdown happens anyway.
What will happen if I will remove battery and use bypass cable instead?
Will the board be able to draw at least 15W from standard power supply?
Would it be possible to draw > 15W from different DC adapter that way?
What will happen if power demands (e.g. 100% CPU + NVMe) will be more than what can be taken from a DC adapter?
Will some hardware throttling be in place or just emergency shutdown / hangup will happen?
I want to build some packages on the PBP, not just the kernel, so I'd like to have as much power as possible and ready to remove battery for that case (anyway most of the time my PBP is at home and I can always re-insert battery for travels).
I also want to install NVMe drive, but additional power drain is bloker for now.
