(03-08-2017, 09:18 PM)MarkHaysHarris777 Wrote: [...] apparently there is (although I can not prove this) a 1Gb board with the jumper. I have assumed that the photo of the 1Gb board was correct (as well the 1Gb schematic) , and that the jumper came in with the 2Gb board.
IMHO the jumper is a really dumb engineering mistake; and even the schematic for the 2Gb board has a note (which is an error) "When using DC 5v and battery supply together disconnect J9 1,2,3,4" [...] I leave the J9 jumper on vbatt, leave the battery plugged in, and leave the pine DCIN plugged in... if and when the power goes out (happens in my neck of the woods) the battery (lipo) keeps things running for up to 10 hours. The J9 jumper in vbatt position ensures that the 5v on the pins and the usb will continue.
That was my belief also... that there was a 1GB Pine64+ with a jumper, but I can't see anything to support that. If that is not the case, the shop page is NOT correct as it shows a 1GB pine64 with a jumper, and the schematic is correct.
I'm in two minds as to whether it is a mistake or not. It certainly seems to have been an afterthought. I also usually leave it in the BAT position regardless of external power or not, for the same reason as you. Hence my interest in dual power supplies/battery power option for future designs... as it means the device has a built-in UPS as a bonus. However, I have had problems with automatic power switching designs in the past... with the most disastrous been the power circuitry self-destructing because it automatically did the wrong thing... so it needs to be robust and "fool-proof" (was a very strange interaction between the PMIC in charge mode, 5v boost circuitry, and a battery with self-protection circuit).
However, I do find it handy to have the jumper when back-feeding via the rPi header, or when needing to power a USBHDD that needs more power to spin up than the PMIC will give it.
