Explanation of why the Battery won't charge to 100%.
Except for the Intel® NUC 9 Extreme Laptop and the Intel® M15 NUC Laptop Kit - LAPBC, all the other Intel® NUC Laptop Kits may not charge to 100%.
When the battery gets charged to 100%, the battery will not begin charging again until the battery charge goes below 90%. As soon as the battery is at 89% or lower, the battery will start charging, unless the battery charge level is set lower than 100% in the Battery Health Optimizer section of Intel® NUC Software Studio, see below.
If the Battery Health Optimizer section of Intel® NUC Software Studio is set to lower than 100%, customize will be selected and the number next to the up and down arrows will be set to less than 100%. Select Charge to 100% to set the battery to charge to full.
The Intel® NUC 9 Extreme Laptop and the Intel® M15 NUC Laptop Kit - LAPBC, do not support the above feature.