I assume you are on a Mac?
While this isn’t precisely a solution, when you’re frightened about lightning cables continuously disconnecting/reconnecting to your Mac and may’t get a strong connection to switch knowledge, then you definitely may wish to run the command sudo killall -STOP -c usbd in terminal which is able to scale back the facility draw from 2100 mA all the way down to 500 mA.
The USB 2.0 customary permits the host (i.e. your Mac) to offer 500 mA of energy to your connecting system. Nonetheless by some “Apple magic”, iOS units related/charging from a Mac can draw a further 1600 mA of energy (as much as 2100 mA of energy), offered you employ an Apple accepted/official lightning cable. That is regardless of lightning cables being USB 2.0 cables that ought to solely draw a most of 500 mA as per the USB 2.0 specification. For this reason on Home windows, related iPhones will cost a lot slower (since they will solely draw 500 mA) while on macOS, join iPhones can cost sooner at 2100 mA.
Sadly, due to this “Apple magic”, I’ve discovered lightning cables may be fairly delicate to the smallest of faults (i.e. a single pin is barely bent, particles/mud on the pins, and so forth) that may make the 2100 mA energy draw fairly unstable when related to a Mac. In order the Mac-iPhone connection is making an attempt to barter a continuing energy draw of 2100 mA, any fluctuations causes the Mac/iPhone to suppose one thing has gone defective and makes an attempt to repair it by disconnecting/reconnecting in very fast succession (we’re speaking milli seconds). That is extra prevalent when your iPhone is on a really low cost and extra prone to have an effect on Mac laptops (significantly on the left IO ports, however proper IO ports are additionally prone). That is to not say it would not occur on desktop Macs, nevertheless it appears extra prevalent for MacBooks unusually…
Anyway, I digress, by working that terminal command, you pause the usbd course of, which is the “Apple magic” course of that configures iOS units to cost from an Apple Mac as much as 2100 mA energy draw. As soon as that course of is stopped, the Mac will restrict the facility draw to your iPhone at 500 mA, which is rather more secure and thus will permit you to join and switch knowledge positive, (albeit it can cost as sluggish as on Home windows).
If you’d like extra particulars on the problem with usbd course of, I’ve achieved some thorough troubleshooting and defined fairly a bit about it in my very own query right here: iPhone-Mac connection concern and what does the usbd course of do?.
Additionally observe, while technically the lightning cable is defective, I discovered that it is actually the smallest of faults that causes this instability concern, even when the cable bodily appears completely positive and nonetheless costs completely quick when charging immediately from an influence adaptor. I’ve had numerous of official Apple lightning cables (purchased immediately from an Apple retail retailer) expertise this concern inside simply 2 weeks of utilizing the cable. That is regardless of being very cautious with not bending the cable, preserving the pins away from particles/mud, guaranteeing the pins don’t get broken, and so forth. There may be actually nothing you are able to do about that sadly. Nonetheless, as I stated, they’ll work completely positive charging from a wall charger, or join completely positive to a Mac if it is drawing solely 500 mA of energy.
Once more this won’t clear up your query, but when it is a lightning cable that is continuously disconnecting/reconnecting and all you need is a secure connection to switch knowledge, then I would advocate working that terminal command to pause the usbd course of, which is able to drop that energy draw to a way more secure 500 mA (which is what the USB 2.0 customary specifies anyway).
Good luck
Edit: Whelp, I did not see your remark referring to degrading your battery while performing an iTunes backup. Nonetheless, I am going to go away this put up up in case it helps you or others sooner or later
