I found this pump:


Now, I want to control it from an Arduino.

Is this a good relay to use?


I want to use a 12v battery for the pump.

  • You don't need a relay - a simple N-channel MOSFET will do the job. Oh, and don't forget the flyback diode. A pump is just a motor, after all.
    – Majenko
    Oct 13, 2016 at 12:04
  • You need to check the voltage rating and the current rating of the relay. So in your case, the relay should have a rating of at least 12V DC, and 0.35A of current. Both values are really low, so almost any relay will work. The relay you linked to doesn't have a DC rating, only an AC. But I don't think that's a problem in this case.
    – Gerben
    Oct 13, 2016 at 12:23
  • 1
    @Gerben A general rule of thumb: DC rating is 1/10th - 1/20th of the AC rating. Current remains constant. It's all about arc extinguishing - AC auto-extinguishes at the zero crossing, DC doesn't.
    – Majenko
    Oct 13, 2016 at 12:58
  • @Majenko thank you. I didn't know about that rule of thumb. I knew it was lower. Since the pump in question is only 350mA, the 10/5A relay from pololu should work.
    – Gerben
    Oct 13, 2016 at 14:12

2 Answers 2


I see people are recommending mosfets (which is the best option). Keep reading this if you still want to use relay. There are two kind of relays, mechanical and solid state. Mechanicals are cheap but they can be noisy (they make sound) also they have low life expectancy compared to solid state relays. On the other hand solid state relays are faster with everything else but they are expensive. Also you need to check voltage and max current rates before buying.


About the relay, you can buy a low cost relay from aliexpress like the following one or other variant.


It's well within your desired voltage and current range and works readily with arduino.

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