First Battery Assembly failed to show level of power after 6 weeks. Flashlight was not working. I contacted Seller to claim the warranty. I was upset regarding proof pictures demanding, but I waited for few days to cool down and took several pictures to show it failed to charge. The seller sent me a brand new without requesting to return the failed unit. I got free time and battery to perform a failure analysis and I teared down the battery into pieces to measure voltage. I learned the Jumping Battery failed due the failure of the circuit board. I hope the seller sell the circuit board to repair. Great Seller ! Reviewed by a Mechanical and Electrical Engineer