Vince's Cambodian flashlight (Patreon)

Taking apart Vince's Cambodian rechargeable flashlight

Vince the crew chief routinely travels around the world working on events. While in Cambodia he bought this rechargeable flashlight for us to take apart. The circuitry is very minimalist but still allows a rechargeable battery to be charged directly from the mains via slide out plug prongs. The use of a miniature lead acid battery (the acid is usually soaked into a fibre in these), means that charging can be implemented as a basic trickle charger, with the battery venting the electrolyte slowly as gas at the end of the charge cycle. For this reason they recommend charging the flashlight for less than 15 hours. If left charging continuously, the lead acid cell would gradually lose all its electrolyte as gas and go high impedance, with the simple charging circuit putting out a higher and higher voltage. Sealed lead acid batteries are also very prone to damage through electrode sulphation when over-discharged, so they recommend charging the unit as soon as possible if the LEDs go dim, and topping the charge up every two months when not in use. The instructions also warn against using the flashlight while charging as "Otherwise it would burn the electric stuff and elements." The very simple charge circuit means that this unit will also charge on 120V, albeit at a lower current. They claim a run time of 48 hours when fully charged, but in reality the light will start bright and rapidly get much dimmer. After 48 hours of use it will be a very dull glow at best. If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- https://www.bigclive.com/coffee.htm This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty. #ElectronicsCreators