"USB supplying power to attached device" notification

This started about a month ago. Was not really a problem; could still charge normally & when I did charge the notification would disappear for several days. Starting this week, the notification was constant (could not be removed); tried rebooting, safe mode, cache clear, & FDR. I also tried to disable from developer options. Starting Wednesday the battery started draining fast & on Friday I could not charge phone. Some people have had this problem on other phones (per internet search) but very few & not any 6P.

This morning I used spare cable (usb into computer, regular micro plus adapter to phone) Inserted into phone with a LOT of pressure; started charging; also worked using battery pack. At least I may be able to charge now; but notification is still there & battery is still draining probably 6 to 7 % per hour with no usage & screen off.

If the battery life does not improve by tomorrow; I will probably go to Verizon store & get a very cheap phone. We are going on an extended camping trip (old & retired) next week & I don't want a phone that may or not work & charging could be a problem (can not depend on having electricity except in truck).

Any suggestions would be appreciated.