As an update for you BBold:
First, I've never gotten great battery life, and I have the sleep problem, so my unit is not some miracle exception.
Today at the coffee shop coming off a fresh reboot I only opened Drawboard PDF, Outlook, mysms texting app, and OneNote, and detached at 100% on both. The battery drained linearly and I was at 24% of the CLIPBOARD after 3 hours flat. This is the best I've
ever gotten, and seems it lived up to the billing by MS. I think the key is that my fan never turned on, especially since I never opened a browser. I had WiFi ON, location off, bluetooth on, power saver on, brightness 50%. CPU was typically operating at 4-9%,
RAM at ~4 GB. I was basically just reading and annotating a PDF with the Pen the whole time.
When I re-attached, my keyboard was still at 100% and the calculated total battery was 80%. This makes sense since 1/4 of the battery was at 1/4 capacity (screen), and 3/4 of the battery (keyboard) was at 100%. So if you projected this out (multiply by 5)
I could theoretically get 15 hours total at this drain rate.
Now, in practice in full laptop work mode, I tend to get 6-7 hours, or ~4-5 if I don't hold back. So I think that:
- The clipboard will drain much more slowly when detached due to the inherent connection power leakage (hopefully they fix)
- The battery really is capable of the 12 hour performance but with very limited actual function. The professional reviewers got 12 hours but they only had one video player program open with no other interaction.
- The real key is to keep the fan off by keeping the CPU usage low.
I would encourage you to try the actual simple video playing drain test, or else the limited programs open detached like I did to see if your unit is actually defective or if it's just a case of MS stating the "best case scenario" battery life and misleading
us, which you may or may not want to deal with.