Yes, it will, and it doesn't have to be 50 hours continuous. The key is that you will want to charge up the battery. That can be done in several overnight charging sessions if you want. It will take a total of 50 charging hours (minus discharge while in use) to charge up the clock battery.
May I ask how many days the clock battery should last before having to be recharged? I've done the 50-hour thing several times and I still have to reset the clock after not using the scanner for 2 or 3 days.