Battery Weight? Does the weight of the battery really make a difference? Yes, in a way it kind of does, not necessarily for carrying weight, but what I have found that the heavier it is the more it bounces. Also the heavier it is the tighter you have pull the strap on your head. Lithium batteries are lighter than alkaline by almost 40%. I have been using the Energizer Lithium AAA’s weighing in at 0.269 oz (7.6 g) each, compared to the Energizer Alkaline AAA’s at 0.431 oz (12.2 g) each. Now we are talking about 15 grams which is equivalent to 3 nickels. Is that enough to worry about, that’s your call.