DIY Battery Charger: LM2596 Module Guide

If you find yourself with numerous nickel-metal hydride toy battery packs but lack a suitable charger, consider crafting one yourself. Utilizing an LM2596 constant current constant voltage module, you can assemble a charger with ease. Begin by sourcing a defunct power adapter casing.

Next, acquire a 0.36 voltage gauge and integrate it into the casing by drilling appropriate holes, as illustrated below. 

If intending to power the charger with a 12V 1A adapter, install a 5.5|2.1 socket accordingly.

Additionally, keep a small wooden stick handy for adjustments. 

Pay close attention to the main module's heat dissipation, securing all components firmly with hot glue.

For output, employ connector pins to ensure compatibility with standard battery pack plugs. 

The wooden stick is used to adjust the power output voltage and current, so you don't have to stick a screwdriver in every time to adjust.

Once assembled, test the charger's functionality, noting its performance nuances. While the module's minimum charging current of 30mA may limit its efficacy with nickel-metal hydride batteries, it proves highly effective with lithium batteries and supercapacitors.

Furthermore, the charger offers the added utility of battery voltage measurement without requiring a power supply check. To enhance safety, contemplate integrating a diode into the voltage gauge to prevent damage from reverse connections. However, be mindful of potential deviations in gauge accuracy and non-linear voltage drop characteristics associated with diode integration.