Power bank that can be charged with apple "lightning" cord recommendation

[orbital]

I imagine that if you test each of those batteries, that you'll find that at least one of them isn't coming up to full charge.

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Tested and topped all off at 4.2V

Been running them in a P70 emitter light for ceiling bounce today because it was cloudy,,
runtime is similar to my Samsungs'.
Also, I soldered small magnets on two of them for my Fenix headlamp, they need buttontop cells.

No issues.

 

[Lynx_Arc]

Won't fast charging the cell phone battery stress the battery and shorten its life?

If done properly batteries that are discharged can be charged a lot faster without damage and ramp down in current as it accepts more and more charge. I believe chargers and batteries are more smart now vs when Qualcomm's fast charge 2.0 came out which is what my phone uses. My phone is 5 years old on the original battery and I try not to charge it above 90% or discharge below 20% I typically run it between 35 and 85 percent charge. It is likely that phones don't charge batteries to 4.2v perhaps 4.0v like tool batteries are 20.5v which is about 4.1v/cell
I typically don't charge and use my phone even half as much as most folks do and have only drained it to 0 twice and charged it to 100% only a few dozen times when I forget it is charging.

 

[orbital]

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Forgot to add,
all six cells were within 0.015V immediately after removing them, which is negligible.

The cells are fine, the little controller in the powerbank board was flaky and not turning Off,
thus discharging slowly, and that part is no longer {..}