After announcing the Surface Power Cover, which acts as both a keyboard as well as an external battery, back in September, Microsoft is finally releasing the accessory later this month. The Power Cover is almost double the thickness and more than double the weight of the Type Cover 2, but it will add up to 30Wh to the tablet, or up to 70 percent more battery life. Just like all of Microsoft’s Surface covers, the Power Cover will snap onto the tablet, but this particular version also charges the device while it’s in use.

No backlit keys on the Surface Power Cover

That extra battery life will be useful for the original Surface Pro, or the Surface 2 and Surface Pro 2 that it also supports. Although the typing experience on the Power Cover will be similar to the original Type Cover, it will not include the backlit improvements that the Type Cover 2 ships with. Microsoft is taking preorders for the Surface Power Cover in the US, Canada, and Japan, and it’s priced at $199.99 with a shipping date of March 19th.

Alongside the Power Cover, Microsoft is also expected to launch LTE versions of its Surface 2 tablet shortly. A Surface 2 tablet complete with AT&T-ready LTE support passed through the FCC recently, and WP Central reports that the devices have started arriving at Microsoft Stores ready for an official launch. We’ve reached out to Microsoft to comment on the Surface 2 LTE availability, and we’ll update you accordingly.

Update: Microsoft claims Surface 2 battery life can increase up to 70 percent using the Power Cover, while the Surface Pro and Surface Pro 2 battery life increase is up to 60 percent. Both estimates are based on video playback, so the end result will vary. A spokesperson says the company has "nothing further to share" about LTE Surface 2 availability.