Built a small 18650 charger this weekend... wanted a package smaller than the small Xtar with voltage display...

Batteries and Chargers Chargers
1

Decided to use a single 18560 holder and the little USB charging board that HJK tested. I also used the red led voltmeter, it activates at the lowest voltage of 2.5vDC. The parts are attached with black silicone and hold rather well.

I did forget to calibrate the voltmeter before mounting it and it is off about .06 volts. So, I will cut it off and recalibrate it.

I would like to find a better battery holder, this one does not fit button top protected cells well, they are to long.

Matt

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Pretty cool.

3

cool, nice work. how do you calibrate the volt meter ?

4

I use an older Fluke bench meter and a slightly newer Fluke multi-meter and average the voltage on a power supply and calibrate to it. There is a small trimmer on the back of the little meter that will calibrate it.

Matt