@TAImatem Ah, yes. I've heard the battery memory issue reportedly only occurs if the users pin the capacity on 40-80% without a monthly cycle of deep charge. It is advised to calibrate the capacity by draining the battery near low and charging the battery 100% once a month to negate it.
@pauliunas If it were an ARM based device, like the iPad or any Android smartphone, it is not much of a concern since it's efficient power usage when it is used actively/passively, and I have to be on board with you with the convenience issue.
However, the PF is full PC and of case I would like to benchmark it similarly to the Surface Pro 4 M3. Based on the SP, real/moderate usage with 40 Wh would last the device 5-7 hours (the 9 hours+ battery life is tested on menial light activity, see link below for the reports). People have different usages for 2-in-1, but if it is their main device it won't last them a day without charging twice a day and it would be bad for the capacity/life cycle. This is more true to laptops/2-in-1s if the user require heavy usage all day and requires it plugged-in all the time; and as far as I know there are two main causes/habits really, that ruins internal [Li-on] batteries faster:
- Keeping the battery (even 'smart charged') near full capacity, that is 95-100%; and\
- Using the battery from full capacity to low capacity frequently (100-low%)--even on experience, manually keeping the charge 40-80% doesn't cut it for me.
The battery charge limit that many laptop/2-in-1s manufacturers use (Samsung, Lenovo, Dell, etc) are usually included and can be turned on/off by the users. For me it is a win-win to have it since it is optional to the user, and it actually helps the consumer to things they cannot repair/access.
Keep in mind the point of the BIOS/hardware feature is not disruptive or limit "on the go" battery life since you can go lower than 40% if not plugged-in. The most important feature is capping the battery at 80% (eliminating frequent charge/discharge of battery), which is again a feature that users may like on office/home.
If PF is geared towards people always on the go, this could be useful in conjunction with a power-bank (since it is better to lose a $30 ext. battery), or they can just turn it off and enjoy 100% capacity.
Surface Pro 4 (Notebook) Battery Life - Anandtech
Battery University "Prolong battery life" [Li-On]
What can the user do
A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid. To make this feature user-friendly, a device should feature a “Long Life” mode that keeps the battery at 4.05V/cell and offers a capacity of about 80 percent. One hour before traveling, the user requests the “Full Capacity” mode to bring the charge to 4.20V/cell.
Sorry for long post, mate.