I have an iPhone 6. Bought in 2017, so only 1 year old or so. Battery was working perfectly fine. I would get 2 days out of a charge with my level of normal use. Then I charged it using the cigarette lighter USB charger, and it hasn't worked right since. Now, instead of 2 days use, I only get 1/2 day. The battery drains four times faster than it did just the day before charging it in cigarette lighter. It's almost unusable now, because it drains so fast. DETAILS: I ran out of battery on the road, and needed to take photos and use GPS. I was at 0% battery. I charged it using the device in the pictures attached. (takes a long time to charge it, I don't think it gets enough voltage or something this way). It got up to about 5% battery. Then I stopped to take photos. Battery ran out again. Charged it to about 3% again as I drove. Got out, took more photos. Battery died again. Same thing. Charged to about 5%, then drained it again taking video. Then plugged it in, used the GPS as I drove home. Ever since, the battery's been dying 4x faster than normal. It's warm to the touch (even when I haven't been using it). I tried charging it all the way up with normal wall charger a few times. No improvement. Strange thing is, if it's in airplane mode, sometimes it doesn't hardly use any charge at all. 6 hours overnight and it's still at 100% in airplane mode. When not in airplane mode it drops 10% every hour, even when not being used for anything (and all apps are closed). Today I used the phone and it's down from 100% to 16% in 4 hours. Anybody know how what might have happened inside the iPhone or how to fix it? Does it need battery replacement?