Arduino And Relay, some help for this little 12v project

Hello all,

I am trying to connect a 12V fan heater to the arduino,

the result that i would like to get is using the arduino UNO to power on and off the heater,

i am little bit confused about using relay and i have got some question about it,

but first i will tell you what i am using in this circuit:

the battery of the circuit will be a 12V 45Ah car battery ( not connected to a car )

the heater is 12V 13A 150W.

Genuine Arduino UNO

Now the first question is what kind of relay module should i use? for example is this one i chose ok ?


1,normally open interfaces Maximum load : AC 250V/30A, DC 30V/30A;
2, Using SMD optocoupler isolation , driving ability , stable performance ; trigger current 5mA;
3,The module voltage is 5V ,12V, 24V are available ;
4 , The module can be set high or low triggered by jumper;
5 , Relay control terminal voltage and trigger terminal voltage jumpers can be powered completely isolated before and after class , to do after two different voltage requirements ( such as a relay with 24V, trigger with 5V), you need to contact customer service to change the parameters , prices have different ;
6 , Fault-tolerant design , even if the control line is broken , the relay will not operate ;
7 , The power indicator ( green ) , relay status indicator ( red );
8 ,Interface design humane, all interfaces can be connected directly via terminal wiring leads , very convenient;
Technical parameters:
Relay version Quiescent Current Maximum current Trigger Current
5V 5mA 190mA 2-4mA
12V 5mA 80mA 2-4mA
24V 5mA 50mA 2-4mA
Module Interface Description :
1.DC +: Module DC power supply positive ( positive terminal voltage trigger );
2.DC-: DC power supply module negative ( negative terminal voltage trigger );
3.IN: Signal trigger terminal ( same as the default trigger voltage power supply );
4.JD +: positive voltage relay control terminal;
5.JD-: negative voltage relay control terminal;
6.DC + and JD + with a short jumper , DC- and JD- cap with a short jumper , triggering the same end and relay control terminal voltage;
7 high and low trigger mode selection , as shown , when the jumper is connected with the L side , IN terminal is low triggered when the terminal is connected to the high level trigger H;
8 normally closed terminal (NC): relay normally closed terminal;
9 common terminal (COM):. Relay common;
10 normally open (NO):. Relay normally open.


The relay will be powered by the arduino 5V/GND + signal like in the picture? ( attached )

any suggest to make this working efficently and to choose the relays in the future is very very welcome,

thank you guys

Please post a link to the relay since

Maximum load : AC 250V/30A, DC 30V/30A

is doubtful with the relay you show in the image. - Scotty

do You know the reason ?

Relays that can handle 30 A at DC usually are a lot larger.
With 30 Amps at 24 volts, you can do some nice spot welding.
If you have smaller contact surfaces like the relay you are showing, it is very likely that it will fail after just a few switches with that kind of loads.

I will try in few days and i let you know. thanks very much