# Wurkkos DL46 Battery Repair > Bringing back a secondhand flashlight after someone pulled out its built-in battery, by reinstalling the cell and resoldering its leads. Canonical page: [Wurkkos DL46 Battery Repair]() Project date: Sep 2026 Updated: 2026-10-14 Category: Electronics repair Status: Repaired and working Tags: Repair, Soldering, Disassembly, Li-ion - **My work:** Teardown, cell reinstall, tab soldering, and reassembly - **Device:** Wurkkos DL46 · board DL46_C-B0 - **Source:** Bought as-is on eBay with the battery torn out ## In short I repaired a Wurkkos DL46 flashlight bought as-is on eBay after someone tore out its built-in battery. I reinstalled the cell, resoldered its leads with the correct polarity, and reseated the rubber O-ring before closing the working light back up. ![A blue cylindrical battery with a metal tab at one end, next to the flashlight's black front cover and its round driver board with MOSFETs and an inductor.]() The cell, front cover, and driver board separated after the battery was ripped out. ## Overview The Wurkkos DL46 is a flashlight with a built-in Li-ion (lithium-ion) battery that isn’t meant to come out. I bought one on eBay sold as-is because someone had ripped the battery out of it. Its leads had been pulled off the cell, leaving the battery loose from the driver board, the circuit board that controls power to the light. I got it working again by opening the front end, putting the cell back in the body, and resoldering the board’s leads onto the cell tabs (the metal connection strips on the battery). Here’s how I did it, step by step. ## Tools and parts I used - A small Phillips screwdriver - A soldering iron and solder - The flashlight’s rubber O-ring (a ring-shaped rubber piece), which sits on top of the battery ## Step 1: Peel off the front sticker The front end, which faces the same way as the light, is covered by a plain black sticker. I peeled it off to find two screws holding a black plastic cover over the board. The cover has holes for the five charge-indicator LEDs (light-emitting diodes), a small opening for the button, and a keyhole opening for the gold contact. _With the sticker peeled off, two screws hold the black plastic cover over the front end._ ## Step 2: Remove the plastic cover I took out the two screws and lifted off the cover. Underneath is the circuit board, marked `DL46_C-B0`, with the USB-C port, the button, and the indicator LEDs. _Under the cover, the board with the USB-C port, button, and charge LEDs, held in by three more screws._ ## Step 3: Unscrew the board Three more screws hold the board to the rim inside the body. With those out, I lifted the board free on its battery leads. Its underside has MOSFETs (electronic switching transistors) and an inductor (a component that stores energy in a magnetic field). ## Step 4: Put the cell back and resolder the leads I slid the battery back into the body, then soldered the board’s two leads back onto the cell tabs. I checked polarity (which connection is positive and which is negative) before soldering. Reversing the leads on a driver board like this can damage it: - **Positive:** the metal tab on the battery board. - **Negative:** the wire coming off the edge of the battery board. _The cell back in the tube, with the board’s leads going back onto the battery tabs._ ## Step 5: Seat the O-ring This is the step I found easy to miss. The thick rubber O-ring goes between the battery and the rim the board screws into, and it keeps the cell from moving around inside the body. Without it, the battery can shift and pull on the new solder joints. ## Step 6: Close it up I screwed the board back onto the rim and put the plastic cover back on with its two screws. The light is fixed and working again. ## Related reading - [OpenFloat Archery]() - [DIY Electric Bike]() - [3D-Printed Rainbow Violin]()