That s pretty fast for a battery to be changed -12hrs. I ran a Jackson that ran off of 2 AAA batteries for production tig welding and only had to change batteries once every month or 2. The solar unit I have now runs off of the arc. No need to set in sun. Just go at it. Under trucks, between frame rails, under a dump bed, inside tool boxes, inside service bodies, ya name it it worked good.

I definately agree that it is well worth the extra $ for a good auto helmet. Ya can change the shade and delay on most. I run #12 shade with fastest response time(sensitivity)- why lag and expose more of the arc to your eyes? Later- Burn it!! <img src="/forums/images/graemlins/cheers.gif" alt="" />