Just read and article about why flashlight batteries corrode in the metal flashlights ( like Mag Lites), especially the aluminum tube flashlights (MAG LITE) and how to fix the situation. The fix is to take a piece of unlined white, like typing paper and make a tube the length of the battery compartment. I checked my flashlights (MAG LITE) and they all had some amount of corrosion inside the compartment. I have some big around wire brushes which I used in my Battery Drill and broke the corrosion off the aluminum cases (MAG LITE). I then covered the batteries with white typing paper which is supposed to be a barrier against corrosion. The author went back in time when the Ray o Vac metal flashlights came out and they all had a paper tube, inside the battery compartmen,t which got him to thinking, it was a fix for the corrosion. He said that he did this fix to all his metal cased flashlights (Mostly Mag Lites) three years ago and yes he had some with dead batteries but the cases weren't corroded. I just did all my metal flashlights (MAG LITES) about 10 each, and even some of my plastic cased flashlights, We shall see if this fix stops the batteries from corroding in the case. Made sense to me. Hope it works cause a flashlight (especially MAG LITES) that costs $30-$40 dollars should last a lifetime, I even have a 3 cell Ray O Vac flashlight with the paper tube inside and there is not any corrosion inside and this light is about 50 years old. My brother gave me one of his 4 cell (MAG LITE) with corroded batteries and they were a bugger to remove, cleaned up the corrosion on the aluminum and they work fine, did the paper fix to that one also, we shall see. Cleaned the corrosion area with baking soda and then coated the inside with anti corrosion agent!! SOUNDS RIGHT TO ME.