New M2Z controller discharging iPhone 6s+ Battery

[Rusty in Bend]

I've done a bunch of online research on this, but everything is "years" old and fits more into "common sense" than any solution epiphany. I've been flying my P4P+ for a couple of years with the integrated screen, so never had to monkey with my phone until my Zoom came today.

Problem: First flight of 10 minutes my iPhone went from 65% battery to 15% and warnings.

Background: It's not the battery that's the problem, as I use this phone for days at a time on WiFi and Bluetooth without needing a charge. The battery in the iPhone is righteous. Shutting off apps and things like that are just goofy suggestions. This is a BIG problem, not an incremental problem with apps taking a percent or two over time. Another data point is that the phone gets "hot" when that has never happened in any other situation. One final piece of weirdness is that as soon as I plugged in the phone, it went from 15% to 35% in about 45 seconds. Then it started charging normally. I'm on the latest IOS, so I know that's not the issue.

Questions:

1. Anybody have any revolutionary ideas that don't fit into the "incremental suggestion" category?
2. Would it work better if I used the full USB connection vs. the side-mini-port? (That's what I try next after my phone recharges.
3. Is there any setting that could keep my controller from discharging my iPhone?

I love(d) my P4P+ integrated controller screen. I'm wondering if I made a mistake moving away from that very solid form-factor that always gave me tons of battery life in both screen and controller.

Any ideas out there in Mavic-land?

 

[Rusty in Bend]

Update ... and weird.

When I use the full-size USB port with a lightning cable, I run through 25 minutes to a drone battery warning, and only discharge about 15% of my iPhone battery. Clearly there's an issue with the side-USB-port somehow discharging the phone battery unnaturally.

 

[idunno]

Have you tried turning the feature on that charges your phone via the remote?

 

[AvatarWings]

I wonder if there is something wrong with the cable on the side. You probably don't have another cable to try, but it may be worth considering...

 

[Rusty in Bend]

idunno ... you're kidding, right? Does that "Phone Charge" feature even really exist, or are you just jerking my chain?

 

[idunno]

I am serious. Its under the third tab in the settings. Just double checked.

 

[Rusty in Bend]

OMG ... that's really a "thing". I found the setting. Thanks!