if my laptop is fully charged, still keeping the charger plugged in to the laptop is good or bad?

Hi rooney10057,

Welcome to the Community,

The power supply to the battery is automatically cut off once the battery is 100% charged.So even you keep the AC adapter plugged in it does not harm your battery.However to save power its better to unplug  and continue to use the system with battery once battery is fully charged.

To have a better battery life,just ensure you charge the battery before the charge becomes critically low.Its better to charge the battery before it drops to 20 to 30 % charge.

Also read Battery FAQ : http://www.dell.com/content/topics/global.aspx/batteries_sitelet/en/batteries_faq?c=us&l=en&cs=19

Thank You

Hi,

Is this applicable to all models?

I have an Inspiron 7548 with 4k display.

Thanks.

Some of this is true for ALL Lithium-ion batteries. However, you should NOT unplug the battery when fully charged. Every time you unplug the power and use it on battery, you degrade the battery; they are only good for a finite number of charges. In addition, if you use it on battery at your desk, and then need to go portable, you might not have much use time left.