Apple-Exclusive Mophie Charger stops charging iPhone automatically before reaching 100%. Why?

[timidhermit]

Recently, I purchased an Apple-Exclusive Mophie Powerstation Plus that has the built-in Lightning charging port and charging cable (the model is no longer being sold by Apple). I tried to use it to charge my iPhone 5S and iPhone 6 Plus. The charger initially appears to be working fine. However, when the iPhone reaches around 90% or so in charge, charging becomes extremely slow and eventually stops automatically. If I want to re-enable charging, I have to hit the button on the Powerstation Plus to restart. Still, the charger will eventually again stop charging on his own.

Is this an iOS feature that is somehow blocking the charger from charging the phones to reach 100%? Or is there a hardware malfunction with the Powerstation Plus? Does the fact that this is the Apple-Exclusive model of the Mophie charger have something to do with this peculiar charging behavior?

 

[Itsedstech]

Do you have optimize battery charging turned on in your settings?

 

[NJHitmen]

Do you have optimize battery charging turned on in your settings?

I was going to ask the same question. Even with this feature turned on, the battery should still eventually hit 100% - but this would at least explain the slowdown in charging speed.

 

[Ralfi]

I was going to ask the same question. Even with this feature turned on, the battery should still eventually hit 100% - but this would at least explain the slowdown in charging speed.

If the OP was checking the battery during their usual down time, then the iPhone may not resume charging until just before their typical hours of operation.