Hi Eric
I went through the whole "shave the beard" thing way back when too. I started out with an Airlite, made by Racal, when then became the Powervisor and then discontinued when 3M bought them out of I recall correctly. The Airlite served me well for a few years, but I then moved up to the one I have now. To answer your questions:
What is the current model number of your unit?
Airstream 200. I do not see that model on the Airware America site anymore. I have the better (Smart) charger to go with it. I have new batteries and a new charger which came to me complimentary from 3M as I also have a Breathe Easy carbon filtered respirator for spraying finishes. The 400 currently listed is supposed to have more airflow, but I have never had a problem with the volume on mine.
How long does your battery last?
Longer than I have had to use them in a single session so far, so I am pretty sure I have the 8 hr batteries. If you mean expected life before I have to replace them, the older batteries lasted me somewhere around six years, although that is going to vary with use.
What's the recharge time?
Not sure, but fast, less time than it takes to wear out the second battery. If you put your battery on the charger at night, it would be ready to go before you were out of bed the next morning.
How do you keep the face shield clean?
Windex. I tried those paste on clear shields, but all they did for me was increase the glare.
How often do you replace it?
Probably not as often as I should. I need a new one now, but they run about $15.00 and will last for a number of years, again depending on how often and how badly you get hit in the face. The scratches are a nice reminder of the things that didn't happen to me! But I am on my second face shield, and it could use a third.
I hope this helps you out some, and if you have more questions, feel free to ask. I am leaving for a demo in NY in a little bit, so I will not be back to the computer until Monday night sometime.
Bill