I recently purchased a quad core Winbook TW100 Windows 8 tablet, similar to the TW801. The tablet gets OK active battery life running for 5 hours. It doesn't last as long on standby as I expected. It is often dead when I pull it out my backpack for a couple days.
Microsoft Windows uses "power plans" to manage the power consumption of windows based devices. Power plan options that let the user trade off performance versus power consumption.
It turns out this is related to the way windows 8/8.1 manages power for tablet and other always connected devices using a feature called instant on or InstantGo. These devices come with a single power plan and new sleep modes that are tightly integrated with the tablet/PC specific hardware. The Windows Power Options panel shows only the Balanced power plan as seen in this image.
This feature, implemented by Tablet OEMs, lets Windows tablets / PCs wake up / receive notifications and other network traffic while the machine is ostensibly powered down. Tablets and other lower power devices are highly integrated built with combined CPU / wireless and other functionality built into a single component called a System on Chip (SoC).
Microsoft provides information about this new sleep mode and how to study power usage on one of the windows blogs.