So to have 80% on the pods and 100% on the car, it would still take 5 hours to fully charge? That seems crazy to me.
It's not that it will take 5 hours to finish charging the pods, it won't charge the pods to 100% until 4 PM. This reduces wear/tear on the battery and should make the battery last longer( in terms of age/years than duration per charge). It's not good for the battery to be charged to 100% and then be held there for a long time. So the optimized battery charging logic will charge it to 80% which is better for the battery. Then based off your past usage pattern, it will calculate a scheduled time where you will likely begin using them again to finish the charge.
You can turn off the feature by going into your iPhone Settings->Bluetooth->Pressing the circled i->Scroll down and turn off optimized battery charging. This will then always charge the pods to 100% whenever they are in the case.