It's impossible to say how long will it take for the pen to charge because no information is provided about the software or the supported devices. Also, the official website is discontinued making it impossible to acquire documents or technical papers in PDF or other format that can be used to get the necessary details. Contacting is still not an option since I believe their emails were tied to the same domain, and if it's discontinued, then all the emails you would send will be returned back into your inbox.
