There are types of auto darkening hoods that use both solar and battery both. In those I think many of them the batteries are of the rechargeable type and the solar does both charge the battery and operate the helmet.
Some where I heard that of those kinds of helmets you would be best to leave them out of the container to get ambient light even when not being used so the solar charges the rechargeable battery. It seems like something you might not be doing and adversely affect the battery charge and maybe the life of the battery too.
If the rechargeable battery was easily attained and the user could change the battery not voiding warranty and it had the same kind of warning and test I can do on my helmet, I would think it be something I'd be OK with.
I just know 2 Alkaline AA batteries are cheap and easy to find and the cost low enough that I think I'm set for quite a while.
By the way the adding the magnifier lens option on my helmet does not seem to be something done very quickly as you have to remove the protective screen and put it back afterward. Since I had not tried it yet, it may not take too long to do, and I hope so.
In any case if the protective screen gets scratched or dirty and cannot be cleaned, it is good to know parts to replace it yourself are available. From what I remember it came with one free replacement protective cover screen with the purchase of the helmet.
The helmet I got is still selling for about the same. It is $100 which some have said that is not a very good helmet you are not safe or something. I don't think so. There are some features like adjusting how fast the darkening starts, the amount of light it will respond to start it darkening, and the amount of shade you get once it darkens, that I think it is fine for me.
Some auto darkening helmets have a switch to change for use with TIG, but mine is only right for use with MIG welding for some reason. Some one here probably knows about the specifics of why there are different types or switch on some helmet.
MT