Victron Smart Shunt

[ICT]

Good Morning,

My smart shunt is not working correctly and I need to know how to fix it. The first thing I noticed is it appears that as the battery is being used up it is not calculating the percent of battery state of charge correctly. I have two 100 amp hour AGM batteries so I have one of my settings at 50%. I effectively have 100 amp hours usable. When it gets down to 75% state of charge should it not have used 50 amp hours? It always shows slightly more as an example it might show 57 amp hours used. Now the second thing is it never recharges back to 100% state of charge. Now I have the Victron MPPT and 635 watts of solar and I am currently in sunny Arizona. It does go from bulk to absorption and for roughly the last two hours of sunlight it is in float mode. When the sun goes down battery voltage is 12.9. I am assuming by going into float mode and having 12.9 volts I am fully charged. I contacted the place that I bought it from and they said I needed to reset the state of charge to 100% as it has to learn what 100% is. They also said it might take a few times of doing this. I have now done it 5 times and the problem continues. So after the reset the next day it will get back to 99 or 98%. The following day it will only get back to 97% and this trend continues losing a percent or two a day. After a few days I can't get state of charge back above 90% although it is in float mode and 12.9 volts. Do I have a setting wrong? Thoughts and all comments are appreciated.

 

[Rocketman]

Yes the settings are slightly incorrect.

Please post a photo of your settings and we can look at them to make suggestions.

It sounds like it is not automatically resetting the state of charge to 100%.

By the way - your current issue is much better than the opposite one - where you think the battery is at 100% but it is dropping a few percent each day.

Also tell us (or post) what the settings are in the SCC (solar charge controller).

 

[ICT]

Thank you for the reply. Smart shunt settings Battery is 200ah, charge voltage is 14.7, discharge floor is 50%, tail current is 4.00%, charge detection time is 3m, Peukert exponent is 1.25, charge efficiency factor is 95%, current threshold is 0.10a and time to go average period is 3m.

Mppt settings--Battery charge 12v, max charge current is 50%, charger enabled yes, Battery preset AGM spiral cell which was the only AGM option, expert mode off, absorption voltage 14.7 v, float voltage, 13.8v, equalization voltage 16.5v, automatic equalization disabled temperature compensation -16.20mV/0c

Not tech savvy and don't know how to do screen shoots. I am still back in the etch a sketch days.

 

[Rocketman]

Ok - on your Smartshunt- if you reduce the charge voltage down to like 14.5 (2/10th below the absorption voltage on the SCC) - that should fix it.

The logic will then be: Reset to 100% - when the voltage is above 14.5. AND the current is below 8a (4% of 200a) for 3 minutes.

Because both the SCC and the Smartshunt voltages were the same - I think your issue was voltage drop. The SCC was delivering the volts but with a little bit of voltage drop , the shunt was not seeing enough voltage to start the 3M countdown.

The other place it could be is in the temperature compensation, but I believe AGM’s charge to a higher voltage in the winter and lower in the summer.

If a 2/10th drop doesn’t work try a 3/10th.

Is your SCC a Victron mppt- and if so do you have the “Smart Networking“ setup?

 

[ICT]

Thanks and I just changed the setting. Yes it is a Victron MPPT and I think I have smart networking as I have the app. I also have a Victron onboard battery charger for when I am plugged in or use my generator.

Again thank you for your suggestion and I will let you know how this works.

 

[Rocketman]

Does your Smartshunt have the battery temp cable (it was an additional purchase item)?

Or are your mppt’s in the same temperature zone as the batteries? If not that is something I would get (and I did get it).

Yea let us know how it goes.

 

[ICT]

Everything is in my camper so all the same temp. I do not have the temp cable.

I will definitely let you know!!

 

[ICT]

So an update on my issue. I made the change and it seems to have worked. It almost seems like it went to 100% a little to quickly but I will monitor and see what happens. Depending on how it reacts today I might try 14.6. I can't thank you enough for this help!!! Now please everyone read below the response I got from Victron. I sent them an email that was almost identical to what I posted here. I replied with a harsh and strongly worded reply.

Many thanks for your request and interesse in our products!

For quotes on pricing, system support, repairs and technical questions in general we would like to advise you to contact your local distributer or authorized dealer.

These can be found here:

So what does everyone think of this response from Victron? Did they even read my email?

 

[ICT]

Well Victron replied back very quickly to my email. Look at this latest response.

If your supplier could not answer your question he can ask his distributor for help, he probably didn’t do that.

Can you send me a serial number to see who originally bought the unit from us?

In that case I can ask them to assist you further.

Who is your supplier?

You didn’t mention that in your mail to me.

I of course replied back. The supplier I bought it from tried a fix but it was not successful unlike the great answer I got here. I wonder what the next email will say? Will they reply again that we don't want to help you as it doesn't fit into our tiny box of how we do business?

 

[KITROBASKIN]

Thinking Victron is a pretty large company and that it is expensive to have customer service techs answer so many questions from less experienced do it yourselfers when they can go to the many vendors who sell their products. This would also probably weed out those who have bought gray market Victron products and clones. Sounds like a viable business strategy that was initially frustrating to me as well.

Hopefully your Victron Smart Shunt is doing what you want, because I can tell you. I have removed my inaccurate Victron shunt (very, very likely user inexperience) from our backup system until things get ironed out with our SOK batteries Bluetooth function. Then I will put it back in the system, and am confident it will be helpful.

 

[Rocketman]

Victron relies on its dealers to provide the support, if dealers have questions/issues it goes up to the distributor, then up to Victron corporate. This also helps get support in the native language.

My guess is the first response was just a “form letter”, trying to direct you to your local dealer. The second was trying to understand the breakdown in support so they can educate the correct dealer and make sure you get the support you need.

Yea try 14.6 and see how it works.

 

[ICT]

Thinking Victron is a pretty large company and that it is expensive to have customer service techs answer so many questions from less experienced do it yourselfers when they can go to the many vendors who sell their products. This would also probably weed out those who have bought gray market Victron products and clones. Sounds like a viable business strategy that was initially frustrating to me as well.

Hopefully your Victron Smart Shunt is doing what you want, because I can tell you. I have removed my inaccurate Victron shunt (very, very likely user inexperience) from our backup system until things get ironed out with our SOK batteries Bluetooth function. Then I will put it back in the system, and am confident it will be helpful.

I am sure you are correct. The big issue for me is when I clearly stated I had tried the dealer first they still sent out a form letter. Take responsibility and set yourself apart from the competition.

 

[ICT]

Rocketman you are correct. Look how quickly you knew the answer. You knew it was a setting and then asked for them. Boom, problem solved. I normally first try customer service before I buy products. Long story here but I violated my own rule here. Guess I have that rule for a reason. I get what they are trying to do and it makes sense but when you get an email from someone saying they already tried that avenue you don't send a form letter. By they way for everyone's information they have not responded back from my last email and I suspect they won't. I am just so sick of companies that are sure eager for our money and then you ask for help on their product and they insult you with a form letter proving they really don't care. Do they not understand that our community is small overall and trust me I will tell hundreds and hundreds of people about this experience. I forget where I read it and it might have been on here but someone said I rather get a good product with excellent customer service than a great product with bad customer service. That is a true and great statement.

 

[KITROBASKIN]

Thankfully we have a choice who we do business with, and no one will force you to buy Victron again, right?

 

[OzSolar]

I'll offer that when it comes to Victron your happiness with them is 100% dependent on your supplier's competency. Victron's business model is to push 100% of the end user support to the supplier. If you shop around for lowest Victron prices thinking you can get some help from the factory you will be all alone in a cold dark place. Sadly there are some really clueless Victron suppliers out there which I'd like think the Victron is actively trying to correct.

 

[ICT]

Great point guys. The place I bought it from was very nice but Victron is a tiny percent of their business. I understand how they might not be an expert on every product across all their different lines. By the way I did not price shop at all. If Victron EVERY thinks they will get all their supplies up to expert status they are stupid. We continue to exchange emails with them telling me to submit to our process because we are so tightly wound up in our own little box we can't have any flexibility at ALL. My next purchase was to be Victron B2B and an inverter. Fat chance of that happening!!

On a different note I change the setting to 14.6 but did not get a real test yesterday as it was a very overcast day here. I did run my generator a couple hours last night and did get it back to 98% but I will give it another day or two. I think I will probably end up at 14.5 but more experimenting needed.

On a different note does anyone have any thoughts on why the state of charge and amp hours used don't line up? Are the supposed to. As I have 100 amp hours of usable battery I would think that when it shows 75% state of charge I should have used 50 amp hours or something very close to that. If it shows 90% I would expect it to show 20 amp hours used.

I once again want to thank every for their comments and especially Rocketman for his solution!!

 

[Rocketman]

State of charge and amps used…

what you said is the way I thought it worked - but I am on Lithium so my Discharge floor is 5%.

What numbers are you seeing…

 

[ICT]

So I am currently at 80% state of charge and it shows 49.0 amp hours used. It is always lower that what I think it should be. As an example shouldn't I be at 40 amp hours used at 80%?

I so appreciate your help!!

 

[Rocketman]

I think The reason the “simple math” doesn’t work is due to Peukert exponent. The Shunt percentage takes that into account.

Beyond that I don’t know.

 

[ICT]

You are probably right. With that said I would hope that somehow a battery monitor would know that and calculate correctly. Probably shouldn't stress about this as it is rare that I get below about 60 amps used and the days are now starting to get longer.

Thanks again for your comments and help!! Anyone else have any thoughts.

The email battle with Victron continues. They sure don't listen. I told them that the number one rule of customer service is ask the customer what they want and then, get this, actually do it. They were not happy and replied with a nasty email back.