I will vouch for Jim's claim that distance from the transmitter greatly increases drain, and not signal and searching increases the drain even more. I used to literally work in some farmers field, where cell signals might not be present. I was often at construction sites in farm land in very rural areas. Cellular and wi-fi signals were scarce.
CyberPower makes a very good convertor/charger for use in a vehicle, which have very "dirty" power. These will clean up the power and protect your devices.
Brent
On Nov 1, 2019, at 9:44 AM, Jim Saklad via Groups.Io wrote:
Dane Robison wrote:
I'm in a bad spot ¡ on the road, no wifi, and a dying iPhone battery. When I plug?my iPhone X (running iOS 13.1.3) into my MacBook Pro (running Mojave 10.14.6)?using the USB-to-Lightning cable that came with my phone and charges it every?night, I get the usual "Trust This Computer?" message with options to Trust or?Don't Trust it. The problem is, that message isn't on the screen long enough to?click a button before it disappears. It then comes back and repeats the cycle 9?times, after which the phone does not indicate it's receiving a charge.
For anyone interested, I still don't have an answer but I found that putting the?phone in Airplane Mode allowed it to charge. I've since restarted the phone and it?still exhibits the same behavior when not in Airplane Mode.
We mostly never turn off the various radios on our iPhones ¨C the Wifi, the Cellular,?the Bluetooth, and even the GPS receiver.
But the farther we are from their targets, the more energy those radios use to?maintain(or TRY to maintain a connection.?
Turning them off (i.e., Airplane Mode) can greatly reduce the iPhone¡¯s energy use.
Also, charging from the laptop is limiting your charging rate to about 5 watts or less?(I think; later model MBPros with USB-C ports *may* do it faster).
But you can get a good dual PD (power delivery) car charger that will provide 18?watts:
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You will need a quality USB-C to Lightning cble, of course, if you don¡¯t already have one.
Brent