I had an old LED COB light that the power conversion circuit failed, so I decide to gut it and turn it into a lantern / flashlight with a spare 6V sealed acid battery, using a simple DC-DC (boost) converter board.
The 6V lead acid battery eventually died so I converted the unit to accept 6V~12V from outside. The whole lanter was made from whatever leftovers/excess materials I have in my lab, including a PC fan I got for free after rebates years ago. The case is made out of the case for a roll of lint-free alcohol wipes.