Assuming a properly engineered device, the battery shouldn't actually be constantly charging. It should intelligently switch between power sources, as well as e

Assuming a properly engineered device, the battery shouldn't actually be constantly charging. It should intelligently switch between power sources, as well as enabling and disabling charging of the battery as needed. I think what is more of a concern would be the possibility that some laptops now tend to unthrottle the CPU when on AC power (or more accurately throttle their already LV CPUs when on battery), which can mean the internal temp gets pretty high and can be bad for the battery. That being said, we have no guarantee that the power management is being done properly, but Apple seems to really have a handle on the power usage of their devices (even if they can't quite figure out their connectors or software). It's definitely a concern on lower end laptops.