Office 365 Licensing token roaming, lifetime Token

I want to use Licensing token roaming to keep our users authenticated. I've tested it and it works. But I want to know how long the token will be valid? When will the user be asked to enter his credentials again. Also I like to know if there is any way to set that lifetime to infinity (read: as long as possible). Because a lot of our users don't remember their password and I don't like to reset them every time.