DIY: Upgrade Aicevoos 58D to Lithium Battery

In the previous DIY article, DIY Multimeter: NJTY T92 vs. Aicevoos 58D Comparison, we discussed the comparison and teardown of the NJTY T92 and Aicevoos 58D. Considering that the voltage of 3 AAA batteries ranges from 3.6V to 4.8V, which is exactly within the discharge range of lithium batteries, if you're interested, you can follow this article to convert the Aicevoos 58D multimeter to use a lithium battery.

You'll need to prepare a suitable lithium battery. A 5000mAh battery is too thick to fit, and an 800mAh battery is too small. A 1000mAh phone battery is just the right size. If it sits for too long and the protection board gets too close, it won't charge due to the protection board, so you can simply remove it and use a 4056 board for charging.

After installing the battery, if the buzzer on the board is too thick and prevents the back cover from fitting, you can replace it with a smaller speaker, which will make the sound slightly quieter.

You'll also need to add a lithium battery switch to ensure the battery remains usable if something goes wrong with the lithium battery.

You can attach a transparent plastic strip to the 4056 indicator light and extend it outside to show normal charging status.

If the protective casing is too thick and unnecessary, you can replace it with a strong magnet from a speaker to attach to the back cover, acting as a magnetic protector.

As for the charging port and indicator light status, you can smooth them out a bit more to make them look neat.

And that's it—you're done!