Thank you for that information, I had no idea. I'll keep that in mind. My 4D ML300L might benefit when I run it on high (1002 Lumens). I imagine it sags pretty quick at that setting.Never used Deoxit, but always clean the terminals on batteries with emery board and isopropyl alcohol. Just about every battery has a thin layer of oxidation on the terminals, some may have picked up a minute film of oil from the manufacturing machinery. Doesn't make any noticeable difference at low current, but makes a huge difference at high current, helping reduce resistsnce at the point of contact.