DIY Night Light Upgrade with 18650 Battery

The previous DIY article, DIY Night Light with NSA3182 FT100 Processor, discussed disassembling and modifying an infrared thermal night light to improve its lighting duration. The functionality was decent, but the built-in battery didn't last long enough. For instance, if the light gets triggered frequently during the night, it often requires recharging. So, what can you do in this case? If you're interested, keep reading. If you're facing the same issue, one solution is to use an external 18650 battery for power.

The night light comes with a very low-capacity 14500 (Hongli) battery, which doesn't provide enough battery life.

The light is based on the FT100 main control chip.

When triggered, the current for lighting is (voltage 4V).

Standby current is minimal.

To modify it, you'll need to drill holes in the casing, thread wires through, and use 2.54 connectors.

Fix the light board in place and solder the wires.

You'll also need a single-cell 18650 battery holder.

Remove the side protectors of the battery holder entirely, as the battery will be hard to take out otherwise. Forcing it out could easily damage the battery's protective coating.

Find a discarded 18650 battery, wrap it with masking tape to increase its diameter, and use this to expand the battery holder. Then, use a heat gun to warm up and reshape the battery holder.

This makes it much easier to insert and remove the battery. For the connector, you should use a 2.54 one.

You'll also need to cut a piece of adhesive-backed soft magnetic strip and stick it to the back of the battery holder.

Once the battery is installed, test it and the light should trigger as expected.

This night light can be mounted under the metal shelf of a rack, with both the light and the battery holder having magnetic strips. This makes both fixing and moving the setup very convenient.

And that's it—you're done!