What does “Power Saving Function” mean? Sandra Salvatore June 19, 2018 03:49 Updated Follow With 10% power or less, lights will automatically switch to lowest lumen output. Related articles What is COB? Are Kryptonite front and rear lights waterproof? What does “Memory Function” mean? What is Lumen? The rechargeable batteries do not charge. Comments 0 comments Please sign in to leave a comment.