LI-ION BATTERY CHARGER-12V 1A

Battery Charger there. Based on the label in the image, this isn't just a simple power supply; it’s designed specifically for charging 3-cell (3S) lithium-ion battery packs.
​Here is a breakdown of what those technical specs actually mean for your devices:
​Technical Specifications
​Output Voltage: 12.6V. This is the peak charge voltage for a 3-series (3S) Li-ion pack (4.2\text{V} \times 3 = 12.6\text{V}).
​Current: 1A. It will charge your battery at a rate of 1 Ampere per hour.
​Polarity: Center Positive. The diagram on the label (the dot inside the C-shape) shows that the inner pin of the yellow-tipped plug is the positive (+) terminal, and the outer barrel is negative (-).