I lost the charger for a breast pump, and the instruction booklet specifies a 12V, 2A output. I found a 22.5W universal adapter that can be set to 12V, but at that voltage it is rated for only about 1.25A. Can I use it, or do I need an adapter capable of supplying at least 2A?
3 Answers
A 12V, 2A adapter is the appropriate minimum. Using one rated for 3A or more is normally fine, as long as the voltage, connector, and polarity all match. The adapter’s current rating is its maximum available output, not the amount it forces into the pump.
The voltage matches, but the adapter is under-rated for the current. The pump may fail to start, shut down, or make the adapter overheat if it tries to draw more than 1.25A. It’s better to use a regulated 12V adapter rated for at least 2A; a higher current rating is fine because the pump only draws what it needs.
You could try it briefly, but I wouldn’t rely on it. Some devices use less current than their label suggests, while others will repeatedly cut out when the supply is overloaded. An overloaded, poorly made adapter can also become hot or fail, so it’s safer to get the correct replacement.
Also verify the plug size and polarity, especially whether the center pin is positive or negative. Matching the voltage alone isn’t enough.