Phone-to-Phone (USB C <> USB C) Charging

[GSDer]

For various reasons I tried Phone-to-Phone charging last night, using my old Nexus 6P to try to charge my Pixel 2 XL. When I first connected the devices, using the USB C to USB C cable that came with the newer device, my Pixel 2 XL was charging the Nexus 6P. So I fiddled with the options on the Notification shade on the Nexus 6P and selected it as the power source. I then observed that the Pixel 2 XL was charging so I set everything down and went to bed.
When I woke up this morning the Pixel 2 XL was dead and the Nexus 6P was asleep but partially charged.
Has anyone tried Phone-to-Phone charging and had better success at ensuring the correct charge direction was maintained?

 

[rxgadget]

Huge possibility to not just damage your phones but cause a fire

 

[Kizzy Catwoman]

Sounds very dangerous to me as well

 

[Rukbat]

The phone can supply power, but it's not meant to supply that much power. Don't use it to charge a phone.

 

[axllebeer]

I used my Pixel 2 to charge an iPhone 5S recently. not efficient and killed my battery. I agree with Rukbat. Just don't do that, not a great idea.

 

[Mike Dee]

You can't get much of a charge because once the two phones equalize it stops charging. I would only use it to give someone a temporary boost if needed.

 

[GSDer]

The phone can supply power, but it's not meant to supply that much power. Don't use it to charge a phone.

What is it meant to charge then? The text indicates devices that support USB charging, which describes phones. The USB-C and USB-PD specifications both make it seem like the Pixel (and older Nexus 6P) comply with these specifications.

 

[GSDer]

You can't get much of a charge because once the two phones equalize it stops charging. I would only use it to give someone a temporary boost if needed.

That's not the case. I used my old Nexus 6P as the power source and charged the Pixel 2 XL and the Nexus 6P ran down to about 15% before I disconnected it; meanwhile the Pixel 2 XL was being charged at a pretty constant 400 maH.

 

[Mike Dee]

That's not the case. I used my old Nexus 6P as the power source and charged the Pixel 2 XL and the Nexus 6P ran down to about 15% before I disconnected it; meanwhile the Pixel 2 XL was being charged at a pretty constant 400 maH.

That's because the Pixel was draining the battery of the 6P and not charging. You didn't end up with a charged Pixel unless I missed something. If you had a fully charged 6P you can't transfer all of it's stored energy to the Pixel. It doesn't work like that.