Uni for use in Motorhome

  • The Uni is specifically positioned as 'adventure-friendly', allowing you to monitor and control a camper. I'm interested in using Shelly to fully automate all functions of my Motorhome, but I'm struggling to figure out how to do that.


    1/ Shelly Uni can't really control lights (or any other appliance) directly, since the output currents are limited to 100mA. So, I'm assuming the Uni should be used to digitize analogue switches, correct?


    2/ If so, what Shelly product do I use to switch on/off any 12V battery powered RV appliance (lights, door locks, etc.). My understanding is that all other Shelly products that support low voltage, need a stabilized 12V power source, which is not available in an RV.


    It would be great if someone could explain end-to-end how to enable 12V light control in a camper using Shelly products

  • Hi.


    I'm really no expert on Shelly UNI, since I just got my first one today, so I am yet to experiment with it. As for the other Shelly's I have installed plenty.


    The way I see it, try to think about the Shelly's (1, 1L, 2.5, 1PM, etc...) as relays. They have a way of switching something on and off. Shelly 1 even has what we call a "dry contact". This means that you can have different input and outputs of voltage.


    Shelly Dimmer 2 and Shellhy RGBW2 are also relays, but in both their cases, they offer a certain degree of control, as they allow you to fine tune things as you please.


    As for the Shelly UNI, it tends to allow you to operate things. For me it will be used to opperate old devices or appliances. So instead of just powering up or turning off a socket where I connect my coffe machine, I can actually opperate the button I use to either pour an expresso or a long coffee. It means that you control the machine functions and not just its power supply.


    Based on what I investigated before buying it, it allows you to even take a step forward than this example, as it brings you the possibility of connecting sensors to it, while you can still operate machines or appliances actions. Sensors + controllers = loads of possibilies if you're looking for automation. Of course they only work with lower tensions, like from 12V-36V, but still it is amazing what a litle device like this can do.


    What I am yet to figure out is the way to properly work with them. I'm saying this because all other shelly's come with proper cover, and have well built structures. This one kind of makes me think that will bring about issues when you're trying to hide it or make it fit some small space, as it can be damaged while you're working.



    I hope this was any help and if someone finds I said something wrong, please do correct it.

  • Hi.


    That makes sense. Since the Uni can't really be used as a relay for lights, you need another Shelly device (1, 1L, etc.) to accomplish this. The challenge is that none of the other Shelly devices support flexible input voltage.


    So I don't really understand how Shelly can be used for automation in a motorhome context (as they claim on their website).

  • Hi.


    I think that was marketing. In fact you will be able to use UNI for stuff in your motorhome, since cars work with 12V battery. So if you have old appliances in that van, you will be able to turn them into smart devices.


    Just out of curiosity, do you have anything specific in mind for the motor home automation? Because it actually depends on what you actually want to do. For example, if you have a device like a doorbell on your van, UNI can notify you that someone is ringing it.

  • I'm planning on automating everything that has a switch, including lights, doorbell, starting the generator, turning on the water pump, etc.


    The UNI is not the problem. The problem is the relay. As far as I can tell, UNI is the only Shelly device that can be powered by an unregulated 12V source. But the UNI relay cannot directly switch on lights, etc because of the amp limitations. No other Shelly relay runs on unregulated 12V. Hence I'm stuck.

  • But shouldn’t the UNI‘s outputs be able to control common 12V relays that you use to actually switch the load? I’d just try it and see if the voltage range you encounter (under 12V from a depleted battery with engine off to more than 14V with engine running) works for it. From what I’ve read here the Shellies aren’t particularly sensitive when it comes to the input voltage.


    I’d say it’s well worth a try.


    Good luck,

    Georg

  • I'm planning on automating everything that has a switch, including lights, doorbell, starting the generator, turning on the water pump, etc.


    The UNI is not the problem. The problem is the relay. As far as I can tell, UNI is the only Shelly device that can be powered by an unregulated 12V source. But the UNI relay cannot directly switch on lights, etc because of the amp limitations. No other Shelly relay runs on unregulated 12V. Hence I'm stuck.

    Hi.


    I don't think that's correct. Shelly one can accept 12V for input. If you check the official webpage you'll find the following wiring diagrams:


    shelly1_wiring_ac.jpg

    shelly1_wiring_dc.jpg



    Shelly RGBW2 is usually used on LED strips, which, in the vast majority, work with 12V to 24V. So if you want, shelly 1 is no problem for all the light switches and sockets that you want. Still, keep in mind that shelly 1 is a relay, so you'll be using it for on and off, power up or power down actions.

  • Actually, from what I can assess, from the diagrams, yes. I think you can use it as relay. People may start wondering "what is the shelly 1 for, than?". The answer is simple: you can't use shelly UNI with higher voltage. So unless you are working with 12 to 36V, you cannot use UNI. Also, the UNI's pottencial is a waste to simply being used on relay operations. And of course, it looks way more fragile than the other shellys that have a proper case.

  • Yes, Shelly 1 can accept 12V, but it's REGULATED 12V. The power supply in motorhome will vary between 12V and 14V depending on the state of charge of the batteries and Shelly 1 will not like that.


    The workaround is to install a DC voltage regulator so that anything downstream of that is 12V, irrespective of the battery charge.