Intro

How to charge smart watch without original magnet cable while the new ordered cable is being delivered.

Aliexpress

Magnetic Portable Charger Wireless Charging Dock Type-C/Micro Port for Oneplus Watch2 OPPO Watch X/4pro/3 Pro/3/2/SE

🔺 Issue Description

In some cases you can lost or forget special magnet charger for Oneplus Watch 2 or other similar smart watch/band.

🔧 Issue Fix

Since it's charge via USB and have 4 contacts (pads) one can assume that two of them is ground and power inputs.

I don't know if it has reverse polarity protection, but it should. If you have the actual charger cable just measure the voltage to verify it.

✔ Fixed

Using DIY probe holders I connected 5V from USB cable to the watches and now it's charging. You can also use laboratory power supply, but be careful, voltage above 5V most likely kill watches.

Conclusions