A lead acid battery desulfator is a device that you can build yourself to recondition, recharge and extend the life of your batteries. You can build a lead acid battery desulfator that fits inside an Altoids can for convenient portability. Always exercise caution when working with used batteries because they can leak hydrogen gas, which is toxic and flammable.
Set the Components in Place
Use double-stick tape to affix a piece of perf-board that is slightly smaller than the area within the Altoids can into the bottom of the can. Set a strip of adhesive copper foil onto the bottom edge of the perf-board to act as a ground bus. Set two switches, two resistors, two pots, one field-effect transistor (FET) and one light-emitting diode (LED) onto the perf-board in a way that requires the shortest length of jumper wire connections. Use Krazy Glue to set each component in place. Bolt down the FET with a nylon bolt for further stability. Use double-stick tape to affix thin pieces of cardboard around the perf-board to act as insulation between the metal can and the circuitry of the lead acid battery desulfator.
Drill Holes Into the Can
Drill a hole into the left side of the Altoids can to accommodate the output wires of the lead acid battery desulfator. Set a rubber grommet into the hole to prevent the output wires from touching the metal of the can. Drill three vent holes into the right side of the Altoids can. Drill a hole into the lid so you can observe the LED when using the lead acid battery desulfator. Poke holes into the cardboard insulation at the points where they touch the output wire holes and the vent holes of the Altoids can.
Solder the Wires
Use wires that are thick but flexible as the lead wires of the lead acid battery desulfator. Keep the cables short to prevent losses in the cables leading to the battery. Connect the wires of the lead acid battery desulfator and solder them in place using a thin-tipped soldering iron and 60/40 solder. Use needle-nose pliers to hold the wires in place as you solder. Salvage parts from surface-mount components to use as the electrolytic capacitors. Solder the lead wires into the electrolytic capacitors. Use output leads and clips to connect the lead acid battery desulfator circuit to the battery.