Will this relay board work?

Alright guys I am going to be using an Arduino in my car to control a lot of my off-road lights. (7 of these: http://www.RigidIndustries.com/product-p/srseries10.htm)

So I need a relay that is 12V right? So I’m thinking this one here: http://www.sainsmart.com/16-channel-5v-relay-module-for-pic-arm-avr-dsp-arduino-msp430-ttl-logic.html

This will work right? I will be able to control up to 16 relays (that can control my 12V electronics) independently correct?

Thanks for the tips guys.

With a relay there are two consideration:

  1. the coil
  2. the contacts
    There’s no correlation between the two.

The coil rating is a voltage and usually a resistance. That way you can anticipate the current demand to energise the coil and open/close the associated contacts. You don’t have to have a 12V coil to control a 12V circuit. Your board has a 12V to 5V switching regulator.

The contacts are given a voltage max and a current max. Your application shouldn’t exceed either, lest arcing and sparking result.
The VAC and current specs are often different from the VDC and current specs. You can see the contact ratings in one of the pics in your relay board link. The relays on your board are labelled for 10A output.

RIght I understand the basic properties of how a Relay works. I know the coil needs to be able to be triggered by the Arduino (less than 5V?) and the contacts (that I will control my lights with) I assumed had to be 12V because the lights are 12V. How would I figure out the right rating for the contacts then?

They don't provide a schematic, but from the looks of it there is interface circuitry on that board providing for 5V control of its relays.

They give a "35W" figure for those lighting assemblies, so I suppose that implies, nominally, 3 Amps or so.