Controlling a Fan with the Cerbo GX

[@EXPLORISTlife]

*Diagrams, Step by Step Programming Info & Parts List can be found in the accompanying blog post:* explorist.life/cerbo-gx-fan-control-for-better-ventilation/

[@RVingwithG]

I’m a big FAN of this channel 😅😊

[@CurtisDrew1]

Great timing for me. I'm currently sorting out my Victron inverter install in my Class A RV and will be setting up my Cerbo right after that. I always learn faster by watching others do it, over pouring hours reading written instructions.

[@tpgmsg]

FYI the relay according to the specs in the manual does 6 amps up to 30VDC not 4 amps😊. I am using this relay for a battery heater and it draws 4.5 amps. Great vid by the way and very timely for me.

[@EXPLORISTlife]

Ah, yep! I got the Cerbo relay and the Multiplus relay switched. Cerbo = 6A up to 30A and Multiplus relay = 4A up to 35V.

[@sbramel93]

Realized immediately after seeing my MultiPlus (that’s installed inside a tight space) reach 115 degrees on the outside enclosure that I needed cooling fans. This tutorial made it so easy, thank you so much! I have a 24v system and was easily able to find 24v brushless ball bearing computer fans on Amazon.

[@gottabyke1]

Just in time! I was looking for a thermostat on Amazon last night and then open my email today and see this video. What eerily good timing. Also, I never even thought to check whether or not the Cerbo GX could accomplish this. Seems like a much cleaner option and cheaper too if you already utilize the Cerbo. Thanks Nate! Saved me a few bucks, so I'm happy to pass it along.

[@EXPLORISTlife]

Hey, @gottabyke1! I appreciate that. Thanks for watching! 🙂😀

[@jamescullis]

This is the perfect solution for me in Australia where the fan vent space gets very hot, adding PC fans controlled by a sensor will work nicely, thanks Nat

[@djsmithe]

The Cerbo GX is an amazing little unit.

[@HaskieSubscriptions]

Thanks for all the great info over the years Nate. I have a system with a Cerbo and a Touch display, but I've been getting a craving to make my own display using data that's pulled directly from the Cerbo. For starters, I think it would be cool to have a lit seven segment display for how much my solar is bringing in, SOC, tank levels, etc. But later I think it would be fun to add a speaker and have it play a sound when my batteries get low or something. I realize VRM does all this in some capacity, but an always on display above my dinette would be pretty convenient. I'm a programmer and have made projects with microcontrollers before, so I shouldn't have too much trouble with that part of the project, I just don't know how to get the info from the Cerbo (although I'm pretty sure it's possible). Have you ever done any projects that have done that? Do you by chance know any big topics that I can start researching to get started with this?

[@EXPLORISTlife]

Hey! Thanks for that and glad it has been helpful. Since you've got some programming know-how; to point you in the right direction of what you are after, check out the 'modifications' forum of the Victron Community. It deals with all of that stuff with custom programming through the Venus OS: community.victronenergy.com/spaces/31/index.html Also the Node-RED Victron Forum: community.victronenergy.com/topics/4571/Node-RED.html That should at least give some direction.

[@HaskieSubscriptions]

@@EXPLORISTlife You're the man Nate. I've watched a couple of parts of a Victron web seminar on Node Red since you replied and it's really blowing my mind. This is precisely what I needed. This is going to be FUN. Thanks again.

[@VictorandMJ]

Thank you, Nate, this is video is made right in time for our situation. We just installed the Cerbo GX and two cooling fans and haven't gotten wire them yet. Well done 😊

[@briancase3936]

Nate, thanks for the video I just purchased a Cerbo and I have the unused temp sensor from my multiplus and I didn’t know I could use the temp sensor from the multiplus for temperature reading of my battery bank! Now I don’t have to go out and buy a temp sensor to ventilate my battery compartment. I thought at first the sensor lug needed to go to a lug on the battery thanks for clearing that up.😊

[@tjmarrinan]

Thanks for the update!! When the Cerbo first came out they hadn’t enabled this but the BMV-712 head unit did (and still does). That is an option if it’s closer to your switched load. Also, a cheap PWM will allow you to reduce fan speed, power draw and noise. Mine is set to circulate air from the main cabin when the battery compartment is too hot or too cold since it is lithium.

[@telemaster4520]

This is perfect Nate. The cheap Amazon thermostat in my cabinet doesn't hold the parameters well and has to be continually reset. Ive got that temp sensor in storage somewhere gathering dust. Looks like a fun little Saturday afternoon project. Thanks.

[@paulcurtis5496]

Great topic to cover, I chuckled at 79°f, Taj-Ma-Haul’s A/C is set to 65°f. I love solar powered A/C!

[@svStargate]

Nice video! So, if let’s say I have the inverter and solar controller on an enclosed compartment.. should I use the fans to push fresh air in, or extract hot air out? Or both!

[@FulltimingBrinkley3950]

I LOVE your videos! You make things so simple and easy to understand, and you do an amazing job of telling us how and where to get the parts. For those reading this, I have bought parts from Nate’s store and they worked out PERFECTLY! So I highly recommend buying from Nate! Thank you Nate and team!!

[@EXPLORISTlife]

Thank you so much! We really appreciate that!!

[@tiborchren]

Thank you for the video. Finally, someone showed it. A second Cerbo relay could be used to heat the battery based on the temperature sensor from the BMS, would that be possible? Could it be used in combination with temperature based automation like touch buttons in VRM, where the cooling/heating would be turned on/off manually? Would the relays work similarly on MPPT and on inverters?

[@richardbaldwin7055]

This is what I have been looking for. Thank for this and all your great videos.

[@joaomendes7048]

Great video, as always, explained clearly and to the point! Would be great if you did a similar video for the Cerbo to control the AC (220 or 110V) water heater, say, on SOC of the batteries. Thank you.

[@robbehr8806]

Good video!

[@EXPLORISTlife]

Thanks! 🙂🙌

[@One2ManyHobbies]

Can you make a video sharing how to these fans can turn on when the multi-plus is running in Bulk charge (Putting off Heat) or the Inverter is on.

[@chachi5975]

I just put the temperature sensor near the output fan of the multiplus so when it's trying to cool itself I am adding additional airflow to the compartment.

[@svStargate]

The Cerbo-S GX has no input for the temp sensor, but does has relay ports, so is it possible to make a fan work with RuuviTag sensors?

[@danielkrajcik3070]

Yes it should work with Ruuvi. At least I can configure it with Ruuvi using latest FW 3.41 in Cerbo GX..

[@aaronkatzen5973]

Is there a way to calibrate the temp sensors for the cerbo? I have 3 in my system placed in different locations as well as a higher quality temp sensor and I’ve noticed the victron sensors all run 5-10 degrees warmer. Not a huge issue but kind of annoying, especially when trying to program to trigger things are specific temps.

[@navsingh2566]

Hi mate thanks heaps. I was thinking about setting up some sort of fans for my system and your video poped up. Just one question, what is the size of those fans?

[@RollinHomies]

Thanks for sharing. I’m surprised you chose the cerbo for this aux fan vs the assistant relay in the configuration of the mp. Maybe down the road😉

[@craigmckenzie8028]

Could you use the ground wire instead of the 12v positive wire for the relay so you would be switching ground instead of 12v Thanks for the great video

[@EXPLORISTlife]

I think you'll benefit from the talk I gave at the first of last Fridays livestream if you go look on our channel for the replay.

[@chachi5975]

If you wanted to power a larger load couldn't you have the cerbo control another relay that would be able to handle the larger load? I'm thinking it could control tank heaters that way.

[@EXPLORISTlife]

Yep! Absolutely!

[@chachi5975]

@@EXPLORISTlife is that the only type of temperature sensor that works with the cerbo? What about something connected to it via Bluetooth like a Ruuvi tag?

[@EXPLORISTlife]

@chachi5975 At this time, the ruuvitag sensors can't communicate with the relays of the cerbo. Apparently this is in the works, but not currently a feature.

[@chachi5975]

@@EXPLORISTlife I know it can set as an alarm rule but no action is set there. It's good to know that it's in the works. It would be helpful to have something like that done automatically. Thanks for your response.

[@russfries8088]

@@EXPLORISTlife what would that look like. What would it entail. I’m not an electrician, but I can follow directions. Can I email you directly?

[@tristan-s]

Do you have sensor placement recommendations for a standard victron-driven electrical cabinet? I’d expect that the top of a multiplus ought to get warmest…

[@ppabla5228]

I really like your new trick but my question to you is that enough air flow with those small fan to cool down your storage cabin in the RV trailer.

[@EXPLORISTlife]

Computer fans, depending on the brand, move a ton of air. These ones in particular: amzn.to/4aUeQzY

[@JerryKauffman]

And another timely and well done video! Thanks.

[@michaelskeels4442]

Is there a temp we need to stay under for a multiplus II?

[@wjhann4836]

Nate, is it possible to get other temperature sensing as input - for example the temperature of a MPPT?

[@MsDenisejoyce]

So amazing to find this you show how to ventilate more!!!

[@DallinYoung]

Could the GX be used to start a gas generator in a class A when solar is not keeping up (winter months)? Or is there a better way to auto trigger starting the generator?

[@neomatrix2722]

Great great video I'm A Schneider Electric guy for now but in my heart I'm a victron boy

[@my1little2pony]

can this be programmed for the battery temperature measured by the bms to turn on a relay to run a heater?

[@KU9L]

I have the Cerbo S-GX so it does not have an analog input. Do you think I can install the temperature sensor on my IP-67 Smart Shunt and through Blue Tooth or VE.bus access the temperature data on the Cerbo S-GX to control my relay 2? It would be wonderful if that was possible but putting it all together in my head from the on-line manuals is driving me crazy. The four 12-volt fans I have will use a total of 2.6 amps while running, so it seems that part will work just time.

[@EXPLORISTlife]

I don't think that is an option, no, but you can always give it a shot and see!

[@KU9L]

@EXPLORISTlife Thanks. It was a stretch to hope their SW would grab it just like how their 3rd party tags do it now, but they may not have thought that extra detail important. I did not even know the Cerbo-GX full would have been useful in the resistive input for using it in a scheme for cooling. I remember being surprised that I had the "S" model when I finally pulled it out of the box, so I wasn't aware of the differences until I compared my device to your video showing how to attach the temp sensor. I suppose the MK2 Inverter resistive input is just for battery charging in the event of L.A. batteries? Otherwise I may have to invest $50 in the BT tags or maybe even the $12 stand-alone controllers from AMZ that many are using already. It's all about education & I have learned a lot so far. We support about 75 campgrounds in CO in the USFS, so when our new camp hosts show up with a 50-watt solar panel & a single group-24 battery, as a Fulltimer for 16 years, I can offer them real-world guidance, lol. David

[@philcook1990]

Can this also be used for cabin temperatures to turn on a roof fan like a MaxxAir?

[@UpintheAir.stream]

I am trying to get the relay to activate with the RUUVI Tag Pro, that I have in my refrigerator. I want it to activate a blinking circuit that powers a red led lamp on my wall, so that I know visually anytime my refrigerator is out of safe food temperature. FDA state anything above 40 degress for 1 hour or more, can be unsafe. I think that is a little cautious, but I want to be able to know immediately if it is at an usafe temperature

[@EXPLORISTlife]

Unless they've updated firmware, which I don't think they have, the ruuvi tag is not able to control a relay.

[@UpintheAir.stream]

@@EXPLORISTlife Thank You for answering this, I was trying my best to make sure that I was not missing something, since I am new to the Cerbo GX, BTW I bought my Cerbo GX MK2 from you, Thank You for the fast shipping , and the stickers. I will be getting a Multiplus II from you soon.

[@EXPLORISTlife]

Awesome! Thanks for your business. If you need some more personalized guidance from products purchased from our store, submit a support ticket for some more personalized help: shop.explorist.life/support

[@mrschmiklz]

Uhhhh where are the LED fan lights, guys? Noctua??? Jk. Thanks for the video. It was great.

[@junior4969]

I have 2 stage fans can I use the relay to run both stage some how through nc and no on the 1relay I mean run low stage then as temp climb have the second stage to cut in One wire is power wire then the other 2 wires are both neg wires

[@InDepthAngler]

Is there any way of doing this with a mk1 Cerbo gx?

[@NickMcEntee]

Excellent timing! Thanks for the vid.

[@EXPLORISTlife]

Glad it was helpful!

[@wrightflyerb5]

What firmware version are you running? I cannot get the temperature values to change ...

[@EXPLORISTlife]

It was probably the latest firmware available at the time of making this video. I don't recall the specific number, but you should be able to cross-reference and update as necessary.

[@craiglouw4057]

Legend 💪💪 you know exactly what we need

[@Duffman__]

Can you pair it with Ruuvi temp sensors as well? Can it also work if you flip it? Ie: if an area gets too cold, can it flip a fan on to move warm air to an area until it heats up...? Or do the temps get confused then?

[@oldwave1]

Yes I have done it

[@ticopowell]

Can you set it to activate from a multiplus' internal temperature?

[@EXPLORISTlife]

That's not really what this tutorial is about, but the Multiplus relays can indeed control a fan based on a few different variables.

[@ticopowell]

@@EXPLORISTlife I meant can the cerbo take the multiplus temperature and turn on a fan, or is it limited to it's own temperature sensors?

[@EXPLORISTlife]

I see. I don't think that is a native trigger within the Cerbo, to my knowledge, no. But that's also not somethign I've ever looked for.

[@FFdo.]

can you do this but instead of using the wired temp sensor, using a ruuvi temp sensor?

[@EXPLORISTlife]

Relay switching via ruuvi + cerbo is currently not a feature, unfortunately.

[@tpgmsg]

@@EXPLORISTlife I have just set this up with a ruuvi bluetooth connected to a Cerbo-S GX and it works! The Cerbo-S GX is on firmware v3.12 so maybe the feature is working in the latest firmware. I use this to run a small battery heater at 4.5 amps. Because I want to turn the heater on when the temperature goes below 43F and turn off above 45F, I had to connect it to the normally closed connection on the relay block. That means at 45F and above the relay is active, but because i am using the normally close connection it is in fact off. When at 43F and below the relay goes inactive which turns on power to the normally closed connection and the heater comes on! Quite a mind game but it works. Instead of active / inactive it should be something like activate NO and activate NC. The normally open(NO) and normally closed(NC) are confusing too Also for temp feeds Victron should make it more intuitive. Maybe a temp when it is on and +- temp diff that it stays on until it fails below, if -, or above, if +. Thanks again for all the cool stuff you present in a precise understandable way.

[@vectoredwolf]

I know you're sponsored by Victron, but could you do one of these with a Raspberry Pi running VenusOS too? Thank you! Or at the very least, add it to the blog post? I've been using an off the shelf 12v temperature based fan controller separate from my units (one is PWM one is not). And I'm not sure it's programmed in a helpful way. Finally please convince Victron to give us Temp details from our Multiplus?

[@ieism1]

It's worth noting that Victron sells two different temperature sensors, I believe only one of the would work for this application.

[@EXPLORISTlife]

The one from the Multiplus works and the one from the parts list I made in the blog post works as well.

[@johnplyler7054]

Thanks so much Nate. This is exactly what I need.

[@EXPLORISTlife]

Happy to help!

[@LowPriceEdition]

Nice. My batteries sit in an unheated enclosure. I'll be using this to circulate warm air from the camper into the enclosure when it gets too cold.

[@EXPLORISTlife]

Nice! Sounds like an awesome project!

[@BTNomad]

Excellent! Thanks!

[@husky-1997]

You are the bee's knees, thanks a lot

[@EXPLORISTlife]

Thanks! 🙂🙌

[@mflo1970]

Very good

[@EXPLORISTlife]

Thanks!

[@sutliffgnassi9925]

79 F & 80 F may both map to 26 C internally. 79 F = 26.1 C, 80 F = 26.7 C, & 26 C = 78.8 F. So depends on how much detail they retain internally, and whether the display routines truncate or round. I bet you won’t see this behavior if you change it to display in C.

[@Kevin_Aus]

For a large system which might need lots of automation, control, etc.. this is absolutely worth it because it's relatively easy to understand and program yourself. But for basic functions like what is shown here there are much easier and cheaper solutions.

[@EXPLORISTlife]

Well... nobody is buying a Cerbo GX just to run a fan. They are buying a Cerbo GX to monitor all of the various Victron components in their electrical system and since they have the Cerbo GX, they may want to use it to control fans; which is what this video is about. If somebody already has a Cerbo GX in their electrical system, there aren't any cheaper ways to turn fans off/on through a temperature controlled automation since it's just the cost of the fans, some wire, and a fuse; all of which you'd need with any other type of ventilation solution.

[@halleluYAH144]

Great info, thanks! Any ideas to pair a CGX with a higher amp capacity external relay to switch on/off a 25a water heater element (600w/24v)? I'm looking to control my tanked water heater efficiently, much like how the fans are controlled.

[@chachi5975]

Use the cerbo relay as the trigger for the higher amperage relay powering the heating element. You can program it to be based on SOC so it's only on when you are fully charged to whatever parameters you choose. I have mine set up for "solar dumping". When I'm fully charged, it turns on a relay that controls the water heater and shuts off at 95% (or whatever I choose). My water heater is still working on AC power so the inverter needs to be on and the relay is and AC relay controlled by a DC input.

[@halleluYAH144]

@@chachi5975 This is GOLDEN!! Thanks for the advice! This is the missing link to complete my diy thermal heated floor project without having to fork up THOUSANDS from limited sources! I don't have a CGX yet, but I will soon. May I ask, is your water heater tankless or tanked? I ask coz if it's tanked with capability to swapout to a dc heater element at 12v, 24v, or 48v, you can potentially bypass the use of the inverter/AC to save you some power. The CGX could keep the heat at that sweet spot as thermometer would from just capable batteries and solar.

[@chachi5975]

@@halleluYAH144 I just copied the link that I used to make that work. It's a little tricky but he explained it well. I originally had it set up so when I was fully charged, I could save propane for my absorption refrigerator. I have since switched to a 12v compressor fridge and now have the victron BMV relay wired to turn on the water heater element when it's switched on. I have a travel trailer with a water heater tank with propane/AC heating element. I had the same thought as you with the 12v element but the thermostat on the water heater wasn't compatible. I was trying to keep the inverter off to save power as well but my thinking has changed a bit. Since I'm only using that feature when I'm fully charged, I'm not worried about inverter losses (3.9A) for my multiplus. When I'm camping I'll turn on the water heater AC element but it won't turn on until I'm fully charged and I have it set to turn off at 95% so I have hot water for dishes and a shower, but still plenty of power for the coffee maker in the morning! I hope that gives you some ideas. BTW I simply have the outlet wired to the relay so I could control anything powered by AC and plugged into that outlet. It used to be the fridge and now it's the water heater.

[@halleluYAH144]

@@chachi5975 gotcha! Didn't think about AC uses. Could open up other doors in future. Perhaps turning a cheap deep freezer into a fridge with the thermostat relay setting to turn on/off..hmm. Thanks again for sharring!

[@chachi5975]

@@halleluYAH144 yes the thermostat is available with the cerbo, the BMV is limited to voltage and battery percentage I think. The key to that is the AC relay that's triggered by a DC control.

[@chriswaldfogel2151]

Nate, would you be able to achieve the same results if we are using the smart battery sense for our temperatures? It looked like there was also a bluetooth tab when you went through the menu screen. Thank you as always for all that you do for the rv community!

[@robertlittiken394]

Separate Cerbo GX question. I’ve notice my Cebro GX occasionally reboots. Have you ever experienced this?

[@brin6449]

Look in the settings, there is an option to reboot if it loses network connectivity.

[@grahamunderwood9353]

so basically you could run a fan onto a orion b2b charger to cool it and get a optimised charge

[@EXPLORISTlife]

if it's derating due to overheating, sure!

[@fraserstewart7359]

raspberry pi 🎉

[@davidg.johnson7208]

Geez! All that just to run two cooling fans! Why not just buy two USB fans and have them run by solar!

[@EXPLORISTlife]

If that's what you want and what works for you, then do that. 🤷🙄

[@ianrichardson3228]

My vent extractors have 50c size thermocouples to switch them

[@alanblyde8502]

🙄

[@larryphillips4164]

Epic