I lost the charger for my breast pump. The instruction booklet says it requires 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. Would it be safe to use, or should I find a different adapter?
3 Answers
The voltage matches, but the adapter is rated for substantially less current than the pump may require. It might work, but the adapter could overheat, shut down, or fail if the pump draws more than 1.25A. Since this is a device you may use for several minutes at a time, a 12V adapter rated for at least 2A is the safer choice.
A device normally draws the current it needs, so using an adapter with a higher current rating—such as 12V/2A or 12V/3A—is fine. Using one with a lower rating is different: it may cause the pump to run poorly or make the power supply overheat. Also verify the plug size and polarity before connecting it.
It may happen to work for a short test, especially if the pump's stated rating is conservative, but that is not something I would rely on. The adapter is being asked to provide about 60% more current than its rating, which can shorten its life or create an overheating risk. I would replace it with a properly rated 12V adapter.
Correct voltage alone is not enough. If the pump actually needs more than 1.25A, the adapter may limit its output or repeatedly shut off, so matching or exceeding the current rating is the better option.