Microsoft says the company is "working quickly" to find and fix a battery drain issue that is currently affecting many Surface Pro 3 tablets.

Many owners of the 18-month old tablet have been reporting on their battery drain problems on Microsoft's support forums (via WinSuperSite). The issues seem to center on the models that have the SIMPLO batteries installed.

MSPU got a statement from Microsoft on these problems:

We are aware of some customers reporting a scenario with their Surface Pro 3 batteries in which the system is reporting lower battery capacity than expected. This is a top priority for our team, and we are working quickly to understand the root cause. If you are experiencing this scenario, please contact Microsoft customer support.

Some people who have tried to get their batteries replaced have already been told by Microsoft that the price will be $450 outside of the warrenty period, even though Surface division leader Panos Panay mentioned in a two-year old Reddit AMA that price would be just $200.