This is only an issue if it refuses to charge.
That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device. It is NOT like an iPhone.
Your computer performs best when connected to AC power. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, even with the power adapter connected, the charged state may even decline during stressful work.
When used only on battery, your computer has no extra cushion of power, and will perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)
Plugged in is Not necessarily actively charging. There are up to three micro-controllers cooperating on battery and charging issues. It uses smart charging to charge in the optimum way, and only when necessary.
In general, you should ALWAYS connect AC power when it is possible to do so, and only run on batteries (which will be somewhat slower) when no AC sources are at hand. Your Mac will NEVER over-charge.
