Constantly buying disposable (alkaline manganese) batteries is neither good for your wallet nor the environment. However, for low-power devices like remote controls, there’s one thing to consider: Converting to sophisticated lithium-ion batteries with charging boards is often overkill for a remote control, as they consume tiny amounts of power over years.
There are two ways to say goodbye to disposable batteries: The smart, straightforward way (which is best for 99% of people) and the true DIY tinkering way for electronics enthusiasts.
Option 1: The Smart Switch (Low Self-Discharge NiMH)
Before you get out the soldering iron, there’s a ready-made, extremely sustainable DIY alternative that serves the exact same purpose – without damaging the casing: LSD NiMH rechargeable batteries (e.g., Panasonic Eneloop).
The problem with old batteries: Older batteries lost their charge after just a few weeks (self-discharge) – making them unusable for remote controls.
The solution: Low Self-Discharge (LSD) batteries retain their charge for years. You insert them once, they work like regular batteries, and when they’re empty after two years, you simply recharge them.
Option 2: The Real DIY Project (Conversion to USB Rechargeable)
If you enjoy tinkering and would like to charge your remote control via USB-C like a smartphone, you can convert it to a lithium-polymer (LiPo) battery.
What you need:
A small 3.7V LiPo cell (must fit in the battery compartment, e.g., 150 to 300 mAh)
A TP4056 USB-C charging board (with protection circuitry)
A diode voltage regulator (e.g., 1N4007 diode or a small step-down converter) to reduce the battery’s 3.7 volts to the approximately 3.0 volts required by the remote control (2 x 1.5V AAA batteries) to prevent the electronics from burning out.
Soldering iron, solder, and wires.
Step-by-step instructions:
- Preparation: Step 1.
Remove the old batteries. You may need to trim the plastic tabs inside the battery compartment with side cutters to make room for the flat LiPo battery and the circuit board.
- Solder the charging electronics: Step 2.
Solder the LiPo battery leads to the B+ and B- contacts of the TP4056 charging board. Caution: Short circuits with lithium batteries must be avoided!
- Adjust the voltage: Step 3.
Connect a diode (e.g., 1N4007) in series between the OUT+ contact of the board and the positive contact of the remote control. The diode creates a voltage drop of approximately 0.6–0.7 volts. This ensures a reliable ~3 volts at the remote control.
- Complete the wiring: Step 4.
Connect the OUT- contact of the board directly to the negative contact of the remote control’s battery compartment.
- Installation & housing modification: Step 5.
Securely place the battery and board in the compartment. To allow access for the charging cable, you will need to cut a small opening for the USB-C connector in the battery cover using a small knife or file. Secure everything with a drop of hot glue.