In the XPS 15 9530, there are options in the BIOS to manage battery charging. I believe the default is Adaptive and there are some other pre-defined profiles, but if you choose Custom you can specify a bleep to limit max charge. You can also specify a minimum charge that the battery has to self-discharge to before the system will start charging it again -- so for example if you set your max charge to 80% and your minimum charge to 50%, then once the battery reaches 80%, the system will continue to run on AC power, but it will NOT keep the battery topped up. Instead, the battery will be allowed to self-discharge down to 50%, which normally takes a few days, and only then will the system charge it back up to 80%. This increases battery longevity, as long as you can deal with the potential inconvenience of only having a 50% charge available when you disconnect from the wall.