Victron Venus OS and a Rasberry (1 Viewer)

[Two on Tour]

5.8A ... charging. the Battery Master SHOULD be on as the difference is >0.5V. seems dodgy to me

Oops. misread your post.

It must be doing something right as I obviously don't have a dead starter battery, maybe the BatterMaster is cleverer than we realise.

 

[Hoovie]

Hey,

The SBS is just to monitor the starter battery. Nice cheap easy way that I have in my own van

The dongle is because I need extra USB ports, the Multiplus is connected via a Cat 5.

Battery Master (the VanBitz version) works great with LiFePO4. I have one in my own van as it has always suffered from a periodic parasitic draw. It solved the problem

The Battery Master kicks in when the starter battery gets too low, compared to the LB (0.6v from memory?). This is ideal with LiFePO4 as the resting voltage is 13.2v, so it keeps the SB at around 12.6v.

And yep, the above kit is getting LiFePO4. All being paired with a 460Ah Roamer Gen2 (great bit of kit).

Hope that helps,

Neat idea using the SBS (could have used the 2nd Aux Port on the Smartshunt though?)
Don't understand how the Mk3 Dongle comes into the picture? yes, you will run out of VE.Direct ports once you add in the extra MPPTs, but you would use the VE.Direct - USB dongle, not a VE.Bus - USB Dongle? (I have had to add two of those in my setup to cope with the three BMVs I have installed)
Battery Master. Ok, when I said it is not compatible with Lithium, I mean that a Trickle Charger is meant to work to send extra charging energy to the Starter. Yes, it will operate with Lithium, but it will work regardless of if the lithium is on charge or not, so your parasitic draw is solved by drawing power from the Lesiure battery regardless of charging or not (you could have just connected a wire to do virtually the same thing).

 

[Wissel]

Neat idea using the SBS (could have used the 2nd Aux Port on the Smartshunt though?)
Don't understand how the Mk3 Dongle comes into the picture? yes, you will run out of VE.Direct ports once you add in the extra MPPTs, but you would use the VE.Direct - USB dongle, not a VE.Bus - USB Dongle? (I have had to add two of those in my setup to cope with the three BMVs I have installed)
Battery Master. Ok, when I said it is not compatible with Lithium, I mean that a Trickle Charger is meant to work to send extra charging energy to the Starter. Yes, it will operate with Lithium, but it will work regardless of if the lithium is on charge or not, so your parasitic draw is solved by drawing power from the Lesiure battery regardless of charging or not (you could have just connected a wire to do virtually the same thing).

See what you mean now about the Dongle.

I had to check back to my order and I ordered the VE.Direct-USB, so I've been sent the wrong cable and not noticed. As it happens, I have a few of the Direct cables here that I've ordered since

The Battery Master does exactly what I want it to do - it stops the SB voltage from dropping too much. I'm not using it as a trickle charger, I'm using it to make sure the van always starts

Most of the time it isn't doing anything as it won't kick in unless the SB drops below 12.6v. But if the SB does drop to 12.6v I want it maintained whether I'm charging the LB or not, if that makes sense.

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[Hoovie]

The MK3 Dongle is a fair bit more money than the VE Dongle, so a result there
It can be worth keeping as you will be doing a few more builds I am sure Some of the older Multipluses need a firmware upgrade to work with certain Victron Hardware - and in those situations, the only way to upgrade the firmware is via a direct PC connection - and in those circumstances, you do need the Mk3 Dongle, so handy to keep in the toolbox (Like I said, not used mine for ages, but I keep it just in case and has come into use for that reason).

It is a use for the Battery Master (but it is quite an expensive thing to have instead of a bit of cable and a diode).
FWIW, I use and fit the Ablemail AMT12 Battery Maintainer - cheaper than the Battery Master and user-programmable to use with Lead Acid or with Lithium - and with Dumb or Smart Alternators; AND with normal and high residual draw Starter battery setups.
There is also an override switch where you can enable for it to work whether the Leisure Battery is on charge or not - I occasionally switch mine to override if I am parked up and using the Cab Radio (powered by Starter) to avoid sucking too much power out of it.

 

[Ingwe]

When I go to check on the van every week, I note the SOC of the lithium via the Smart Shunt and then look to see what the Battery Master is showing. If green, then what I do to check the Battery Master is working, is put the ignition key on and turn on the van’s headlights. Immediately the Battery Master light turns to red. This tells me that the Battery Master is working. I also check the condition of the starter battery with multimeter using the test points under the bonnet rather than accessing the starter battery under the driver’s floor.

 

[Hoovie]

When I go to check on the van every week, I note the SOC of the lithium via the Smart Shunt and then look to see what the Battery Master is showing. If green, then what I do to check the Battery Master is working, is put the ignition key on and turn on the van’s headlights. Immediately the Battery Master light turns to red. This tells me that the Battery Master is working. I also check the condition of the starter battery with multimeter using the test points under the bonnet rather than accessing the starter battery under the driver’s floor.

This misses the point I am trying to make - or maybe confirms it!
The voltage of the Starter Battery drops and immediately the Battery Master comes on. IRRESPECTIVE of the charge status of the Leisure Battery when it is Lithium.
A Battery Maintainer is only really meant to be active when the Leisure Battery is on charge. On YOUR system you will likely be drawing power from the Lithium to go to the Starter Battery even when the Starter is fully charged (and the only reason it dropped voltage is the headlight load) and the Lithium could be down to 25% SOC (before the Lithium starts to plummet).
So you are transfering power from a lesser charged battery to a better charged one potentially - is that a good solution?
If you were to say you would not turn on the headlights if the lithium was low, that really misses the point. If the Starter battery voltage was under around 12.2V, it could be taking power from the Lithium even if it is close to dead.

If it were a Lead Leisure Battery, it would not come on in that situation as it is designed with Lead Acid battery characteristics and is wrong for Lithium for the reasons above.


Anyway, if people like the way this works for them, that is fine. If they don't care about the pitfalls, no worries, but I would never fit a Battery Master on a Lithium setup.

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[Hoovie]

When I go to check on the van every week, I note the SOC of the lithium via the Smart Shunt and then look to see what the Battery Master is showing. If green, then what I do to check the Battery Master is working, is put the ignition key on and turn on the van’s headlights. Immediately the Battery Master light turns to red. This tells me that the Battery Master is working. I also check the condition of the starter battery with multimeter using the test points under the bonnet rather than accessing the starter battery under the driver’s floor.

Any reason why you don't just connect the Starter Battery to the Aux input of the SmartShunt to monitor it that way? be a lot easy than lifting the bonnet every time.

 

[Raul]

Wissel, why don’t you use the 4A pin from multiplus board for starter? It’s designed to charge a second battery, a starter when dc bus voltage is above starter battery. You have common -ve.

 

[Ingwe]

Any reason why you don't just connect the Starter Battery to the Aux input of the SmartShunt to monitor it that way? be a lot easy than lifting the bonnet every time.

I asked the installers why they didn’t do this and they said they preferred to keep things simple. They said that the van’s control panel could give the starter battery voltage. I suppose I could just do as you suggest but looking under the bonnet isn’t much of an issue as I also check the coolant regularly after we needed a new radiator in Portugal. €1350!

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[Hoovie]

Wissel, why don’t you use the 4A pin from multiplus board for starter? It’s designed to charge a second battery, a starter when dc bus voltage is above starter battery. You have common -ve.

I think that output is only operational when there is EHU present, so of limited use. (It may be live as you describe, just based on the voltage level but I don't think so).

 

[Wissel]

Wissel, why don’t you use the 4A pin from multiplus board for starter? It’s designed to charge a second battery, a starter when dc bus voltage is above starter battery. You have common -ve.

I realise I could read the manual, but I feel like crap and I'm being lazy.

The 4A pin to charge, assume this only charges when on EHU?

Not fitted a Multiplus before.

 

[Hoovie]

I asked the installers why they didn’t do this and they said they preferred to keep things simple. They said that the van’s control panel could give the starter battery voltage. I suppose I could just do as you suggest but looking under the bonnet isn’t much of an issue as I also check the coolant regularly after we needed a new radiator in Portugal. €1350!

Hmmm. Sounds like they gave an excuse for being lazy TBH.

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[Ingwe]

Hmmm. Sounds like they gave an excuse for being lazy TBH.

Possibly. How hard is to make the connection from the starter battery to the Smart Shunt?

 

[Raul]

Well I was 100% sure as the manual says, and you guys mention, only charges when ehu is life. But, I’m getting readings of 13,1-13,2v on the starter when van stood for 2-3weeks with no charge to starter. Also I have a dash cam and a motion cam of the starter. So this lead me to believe, as the solar chargers and raises the voltage on the LB, the multiplus 4a pin is the only link to the starter, so must be a minimal charge, even if no ehu plugged in.

 

[Hoovie]

Possibly. How hard is to make the connection from the starter battery to the Smart Shunt?

It is just a matter of running a cable (say 1mm2) from Starter Battery +ve to Smartshunt, so it depends really where your Smartshunt is.
You can also connect to any point where you can pick up a +ve from the Starter Battery. So if you have a Battery Master, for example, one of those connections will be Starter +ve, and you could tap into that. Or the Input on a B2B Charger.
When connected to say a Battery Master or B2B, you might find you are getting a slightly lower voltage due to cable drop. And you should have a fuse on the cable near to the battery (the SmartShunt comes with two cables. Your installer probably kept the second one)

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[Ingwe]

It is just a matter of running a cable (say 1mm2) from Starter Battery +ve to Smartshunt, so it depends really where your Smartshunt is.
You can also connect to any point where you can pick up a +ve from the Starter Battery. So if you have a Battery Master, for example, one of those connections will be Starter +ve, and you could tap into that. Or the Input on a B2B Charger.
When connected to say a Battery Master or B2B, you might find you are getting a slightly lower voltage due to cable drop. And you should have a fuse on the cable near to the battery (the SmartShunt comes with two cables. Your installer probably kept the second one)

The Smart Shunt is fitted right next to the B2B charger and both are at the back of the passenger’s seat. I’ve attached a photo taken during the installation. So the distances between the shunt, B2B and starter battery are short. If I’ve followed you, I could connect a fused lead from the B2B charger to the Aux input onthe shunt?

 

[Hoovie]

Yup. A fused cabled from B2B input to SmartShunt Aux. In the VE..Connect app, you will probably need to enable the aux input to be "Starter" (or "secondary" or "aux" - can't really exact name. Basically whatever is not "Mid-point" or "Temp") and jobs down

 

[Ingwe]

Yup. A fused cabled from B2B input to SmartShunt Aux. In the VE..Connect app, you will probably need to enable the aux input to be "Starter" (or "secondary" or "aux" - can't really exact name. Basically whatever is not "Mid-point" or "Temp") and jobs down

Right, going to get a lead ordered. Thank you very much.

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[Hoovie]

Right, going to get a lead ordered. Thank you very much.

This would do the job .... https://amzn.to/34ysfAR

(well done on translating last message - predictive text made it look very odd!)

 

[Ingwe]

This would do the job .... https://amzn.to/34ysfAR

Thank you. The photo doesn’t show the ends of the cable. Not s problem for the B2B input as that is a screw terminal but for the aux terminal on the shunt? I was thinking of getting the Victron one (even though, as you say, one came with the Shunt and has been kept by the installer)

 

[Hoovie]

Thank you. The photo doesn’t show the ends of the cable. Not s problem for the B2B input as that is a screw terminal but for the aux terminal on the shunt? I was thinking of getting the Victron one (even though, as you say, one came with the Shunt and has been kept by the installer)

Those fuse leads are usually a loop so you cut it somewhere in the middle to give two bare ends.
You could get the Victron one and it would of course fit the best, but their prices for a basic cable tends to be a bit OTT!
For the shunt, in the ideal world you want a cable end with a bootlace ferrule, and at the B2B end you want to make it simple a bare end that you push into the terminal and clamp down on below the existing cable.
I can make you a cable if you want, but the cost of postage is such it will be extortionate compared to some of the Amazon & eBay Prices (I don't know how they can supply delivered at those prices!)

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[Ingwe]

Yup. A fused cabled from B2B input to SmartShunt Aux. In the VE..Connect app, you will probably need to enable the aux input to be "Starter" (or "secondary" or "aux" - can't really exact name. Basically whatever is not "Mid-point" or "Temp") and jobs down

Thank you for the guidance. Just to be totally sure, the fused cable goes from the +input terminal on the charger, to the Aux socket on the shunt. I know I’m slow.

Edit: what value fuse do I need?

 

[Ingwe]

Those fuse leads are usually a loop so you cut it somewhere in the middle to give two bare ends.
You could get the Victron one and it would of course fit the best, but their prices for a basic cable tends to be a bit OTT!
For the shunt, in the ideal world you want a cable end with a bootlace ferrule, and at the B2B end you want to make it simple a bare end that you push into the terminal and clamp down on below the existing cable.
I can make you a cable if you want, but the cost of postage is such it will be extortionate compared to some of the Amazon & eBay Prices (I don't know how they can supply delivered at those prices!)

Sorry, our posts crossed. Yes, the Victron prices are up there. I bought a VE direct cable (in case I ever need to connect directly to my MAC) and my eyes are still watering!
I went to the van this morning and was pleased to see that the Battery Master was doing its thing. The SOC of the leisure was 85% and the starter was 12.7v.
I tried to have a look at the BSB charger (and shunt) but couldn’t figure out how to remove the plastic cover of the passenger chair. In the front, the plastic cover just clicks out. I tried doing the same at the back bit it didn’t budge. Didn’t want to use too much force in case I broke something but looking at the photo above, it seems that there are two big holes into which the plastic cover obviously pushes into. So, when I have the lead (and it’s a lot warmer) I’ll have a go.

 

[Hoovie]

Thank you for the guidance. Just to be totally sure, the fused cable goes from the +input terminal on the charger, to the Aux socket on the shunt. I know I’m slow.

Edit: what value fuse do I need?

Fuse .... bigger than the draw, less than what the cable can support.
For your use, something like a 1A fuse is fine, so for a spade fuse, just use the smallest you are likely to have (1A, 2A, 3A, that kind of size).

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[almichie]

What an amazing Post, I’ve got everything now and have programmed the Raspberry Pi and got everything working here before fitting the MH. But I am concerned about load versus top up… I read an earlier post with the same issue.

I have the Victron 75/15 smart solar, smart shunt, Rpi and Huaweu MiFi box which I understand to be ~10watts. My solar panel is unknown but it looks 150-180watts worth. I have 2x 110Ah AGM leisure batteries With a battery master linked to the starter battery. Can anyone say if I am just going to deplete the batteries fitting this all ?

 

[Two on Tour]

What an amazing Post, I’ve got everything now and have programmed the Raspberry Pi and got everything working here before fitting the MH. But I am concerned about load versus top up… I read an earlier post with the same issue.

I have the Victron 75/15 smart solar, smart shunt, Rpi and Huaweu MiFi box which I understand to be ~10watts. My solar panel is unknown but it looks 150-180watts worth. I have 2x 110Ah AGM leisure batteries With a battery master linked to the starter battery. Can anyone say if I am just going to deplete the batteries fitting this all ?

If your on about the draw from the RasPi, then it will depend on how you are powering it i.e. USB outlet or a 12v stepdown PSU.
Mine are powered by a 12v stepdown and about the Pi and PSU draw about an amp, but if that will deplete your hab battery is very difficult to say as they are so many variables with how much your solar is going to produce at any given time.

 

[Hoovie]

What an amazing Post, I’ve got everything now and have programmed the Raspberry Pi and got everything working here before fitting the MH. But I am concerned about load versus top up… I read an earlier post with the same issue.

I have the Victron 75/15 smart solar, smart shunt, Rpi and Huaweu MiFi box which I understand to be ~10watts. My solar panel is unknown but it looks 150-180watts worth. I have 2x 110Ah AGM leisure batteries With a battery master linked to the starter battery. Can anyone say if I am just going to deplete the batteries fitting this all ?

You are going to inevitably use more battery power with the extra monitoring kit, so you should take that into account. The good news is you will know just what your battery use is by being able to keep an eye on it.
If you can, I would suggest the following ....

• Choose a 24 hour period where you don't need your van.
• Disable the Battery Master.
• Disable the Smart Solar.
• Remove any hookup and turn off any habitation kit including the fridge (especially if a Compressor one)

Pick a point in time (say noon) and make a note of the battery SOC and Amp Hours taken (I say make a note - VRM will show you of course anyway)
Then read the same info 24 hours later and see how much the battery SOC has dropped and new Ahs taken. The difference represents the overhead of your monitoring kit (as you have eliminated misc. load out and charge in) in a 24hr window.
Then turn everything on again

FWIW, I find my monitoring overhead is around 30Ah/Day (MiFi, Cerbo GX, RPi, plus various bits and bobs)

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[almichie]

Thanks for the replies, I have two USB drop downs to fit, one for the Rpi and the other for the MiFi as they are is slightly different locations. I will get it all fitted and see what happens - the van is only 5 minutes away so if it is a problem I can disable the extra kit and spend more on extra solar kit to power the monitoring kit…

 

[the1andonly]

Just as a sideways glance, i am currently using an Arduino mega to read a BMV712 on the VE.direct. I only realy use the SOC and voltages right now but can read the state of Alarm and relay, this could be used by the Arduino to control a relay for example (or more than the one all ready in the BMV712). I also read temperatures using 18B20 sensors (Lithium Bat temperature). If anyone has downloaded data from Votronics kit (other than via their bluetooth) i would be interested.

 

[Wissel]

Thinking I might build one of these for my own van. Going to give it a refit later this year (again) and don't really want to spend a load on the Cerbo, unless there are clear benefits?

Could someone suggest what I should buy?

I have Victron chargers and inverter in my van already, and will add a smart shunt. I'll swap my water sensors to ones to suit at the same time.

PS - I ordered a few of the Ruvvi sensors, which have now arrived. Not tried them with a Cerbo yet as it's not installed yet (different van), but installed on my phone and they seem a good bit of kit.

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