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Fra avatar image
Fra asked

Suggestions for improving Victron Connect

hello, after 2 years of use and study I noticed fews things that Victron products can improve a lot with little effort.


1) the count of the cycles of the smartshunt and of the various models of BMV.

A cycle is only counted under 65% ..

This is incorrect in my opinion for lead acid batteries one should count a cycle even at 90% or 85%.

IN my RV the system is correctly sized, the batteries are agm for 178ah, and the photovoltaic of 450 watts.

I live in a pretty good climate and never run out of batteries below 80/85%.

So no cycle counts, apart from synchronizations.

This also leads to an inaccurate reading of the average discharge.

In fact, the average discharge is based on cycles and not on synchronizations.

In fact, I have average discharges of 25/30 ah and this is not detected, since my battery pack is 178ah and I never discharge below 65%. actually never below 80%.


2) it would be nice if the victron Connect app for the smartsolar also displays the internal temperature of the solar controller.

This temperature is certainly detected by the smartsolar but is not displayed.

3) it would be nice in the "trends" section to be able to cross the curves of 3 values and not just 2.

For example "battery voltage + battery current + soc".


it would be nice if the AH count was implemented in the historical trends of the smartshunt. Instead it is the only data that is only available in real time.


4) it is a pity that a small economic accessory is not available that records in a memory all the data of historical trends in CSV format to be exported.

The trend is only available on the App for 46 days and the possibility to save the history every 30 days (but only manually) from the smartsolar.

When I had the Epever-based system, a simple object costing 20 euros would record months of data at a time in. CSV.



I hope these suggestions can be taken into consideration, at least in part… at least the talk of battery monitor cycles.

BMV Battery MonitorSmartShuntVictronConnect
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Trevor Bird avatar image Trevor Bird commented ·

@Fra interesting points however the discharge cycle may be worth reconsidering. Battery manufacturers sometimes rate their battery life in terms of discharge cycles. Some set that to an 80% discharge as a measure of one discharge cycle. If you set the discharge cycle too high ( or not enough discharge) it loses meaning because it may look like the batteries are much older in terms of discharge cycles than they really are. It is possible if discharge cycle depth is not set low enough you may think batteries have really been hammered when really they have hardly been used.

The setting you request for cycle depth may make the concept of discharge cycles lose all conventional meaning.

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Fra avatar image Fra Trevor Bird commented ·

sure, I am aware of this.


however there are some Rolls battery,

screenshot-2022-09-28-10-54-38-345-cnwpsmoffice-en.jpg that have a difference in duration between 2,000 cycles at 30% DOD and over 4,000 cycles at 10% DOD.
My own victron agm battery is given for 1500 cycles with 30% DOD.

In my situation it results in 0 cycles on the smartshunt, when in reality it has done more than 400 cycles with DOD 15/25%.

According to the smartshunt it should last me tens of years.
Instead I know that after 1500/1800 cycles with DOD 15/25% the battery will be exhausted. but according to the smartshunt it will be new.

Only the synchronizations allow me to know the true number of cycles.

Could you at least make sure that the average discharge is always calculated every synchronization?

Because it is currently calculated between total Ah divided by the number of cycles.
And in my case the average discharge is 0Ah, since according to the smartshunt I have not even done a cycle.

but my average discharge is around 20/25 Ah. And it is not detected. Except if I divide the total Ah by the number of synchronizations, in my mind.

The user could be allowed to set the cycle count threshold to their liking.
For example, differently in the case of lifepo4 batteries, or Agm or traction flooded acid.


Thank you.

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Trevor Bird avatar image Trevor Bird Fra commented ·
@Fra …..very good point. Many thanks for the detailed explanation.

Regards,

Trevor

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mark-a answered ·

@Fra:

1) (@Trevor Bird also) IMHO the most sensible calculation of charge cycles iwould be the number of Ah drawn from the battery divided by its capacity. In other words add a cycle each time an amount of Ah has been drawn from the battery which matches its capacity (probably taking into account a configured Discharge Bottom).

3) I support that, esp. the historical data issue with the trends display.

4) I'm going to try a RasPi with Venus OS for that matter.

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Fra avatar image
Fra answered ·

Hallo, thanks for your comment.


I don't agree with this.. and maybe I don't quite understand what you mean.


The reality is that the smartshunt cycle count is totally wrong.

All the datasheets of the best lead-acid batteries report the life in number of cycles and different DODs.

THIS INCLUDES 10% OR 20% DOD.

It makes no sense that smartshunt only counts a cycle if the.DOD exceeds 35%.


My batteries will reach the end of their life with 40 or 50 cycles... when in reality they will have done 1300/1500.

These are not my opinions, but facts.

A lead acid battery that have a 15% DOD discharge , it will get one cycle older.

Obviously less older than after a 50% DOD cycle.

But make no sense that smartshunt consider a battery with 1300 30% DOD cycles , like new. With 0 cycles.


It's simply ridiculous.


That victron doesn't change this thing is more than absurd. And it has no logic.

I repeat.. My AGMs will need to be changed in 3 years. and they will have done their 1500 cycles correctly with an average DOD of 15/25%.


But according to smartshunt they will still be new.☹️

It would be sufficient to let the user decide the minimum DOD in the settings for a cycle to be counted

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kevgermany avatar image kevgermany ♦♦ commented ·
So every user now has to guess what a charge cycle is/means... In case you hadn't noticed, the majority of questions here are from people who don't read the manuals, or don't understand them. Now you wish to add complexity for mostly inexpert users.
At best a charge cycle is a guess at representing average usage. It's one definition across the Victron range and some installers take it into account when assessing claims for battery life expectations. But let's go further.


Let's also factor in other factors which affect service life, such as ambient temperature, operating temperature, rate of charge and rates of discharge. And don't forget battery types and quality. Also maintenance during storage, how long batteries spend in partial states of charge...

Unless you're going to do exhaustive tests over every battery in varying conditions, there is never going to be a realistic charge cycle value. But for a specific battery under tightly controlled conditions, a standard van be defined. But would it be applicable and of value in the real world?


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mark-a avatar image mark-a kevgermany ♦♦ commented ·

I second your statement about factory testing and real world setups. On the other hand @Fra is right about the uselessness of the Average Discharge value with the BMV/SmartShunt when your DoD never reaches 65 % (It hasn't here either). I think Victron should drop the cycles from any calculations and if they want to report a value for charge cycles they should calculate them like I mentioned in my previous post.

The closest estimate for cycles which could be used in calculations like the average discharge and work with all/most real world scenarios probably would be to start a new cycle once the SoC has reached again 50 % of the latest drop.

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Fra avatar image Fra mark-a commented ·
On the average discharge, it would already be a step forward if the smartshunt calculated it according to the total Ah extracted, divided by the number of synchronizations.
in my case this calculation corresponds exactly to my average discharge.
Also each sync is actually one cycle (below 95% and then back to 100%).

whether the cycles are heavy or light, we don't care. or we are of little interest.
What matters most is to have at least one count of the cycles even if we discharge the batteries a little.
moreover a DOD of 34%, which for acid lead is not a little. It is the correct usage.
I rely on the synchronizations which in my case are a correct indication. But it's a stretch.
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mark-a avatar image mark-a Fra commented ·

I more or less agree but I only had one sync since I set up my BMV. That's because Victron does not sync as long as the SoC hasn't dropped below 90 % before rising again. Under the current circumstances it rarely will, until the days get longer, because I save battery life by using the power preferably when it comes in and by having converted almost everything to 12 V or DC at least.


BTW in my first PV system my oldest Gel-Batteries are more than 6 years old and still fully functional. How that? First of all I spare them the overvoltage of the absorption stage which trades battery life for speed of charge. That is, I charge them with the classic IU method not IUoU (In terms of Victron configurations: absorption voltage = float voltage) and I regularly give them a really full charge by keeping them without a load at float voltage for at least a couple of days. To facilitate that I use my batteries in pairs, one in active use the other one being charged to its float voltage only, no load connected. That way my batteries are kept at 100 % SoC, which is best for their health, for more than half the time and I always have a fully charged spare battery to switch over to when rhe SoC of the active one gets low.

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Fra avatar image Fra kevgermany ♦♦ commented ·
I know the victron manuals practically by heart.
I am also aware of all the factors that influence the life of the lead batteries that you rightly mentioned.
having said this, it is not possible that anyone who uses a lead-acid battery correctly (ie with an average DOD of less than 30%) will find the cycle count at zero after years of use.

It is not normal, whatever the point of view.

One purpose of the smartshunt/BMV is missing
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JohnC avatar image JohnC ♦ Fra commented ·

@Fra

I posted this just today on another thread..

"I think that 65/90% range is fine. But should be applied to the range above the set Discharge Floor, instead of the full battery rating.

That would make far more sense to me, allowing for different battery chemistry, and even give some adjustability for those who cycle daily, but not deeply.

I have some 3.5 years on my Smartshunt, and still zero cycles registered on an offgrid daily cycler. Using 50% Discharge Floor (fla batts), the 65/90 would have registered most days and given up something potentially useful."



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Fra avatar image Fra JohnC ♦ commented ·

Okay, this point of view makes total sense. for lead-acid batteries it would be an excellent solution.

I actually have 26 cycles counted on the smartshunt..but only because I tried to lower the total battery capacity.

and in any case the batteries (agm) really have

almost 600 cycles.

Fortunately, synchronizations are taken into account, which in my case are almost daily. So that's 500 syncs.

I pretend like syncs are cycles

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