Victron monitor defaults and programming

[themexicandoctor]

These are my settings on the BMV712 - do they look correct?

[themexicandoctor]

Originally Posted by @Michael

Absorption timer starts after bulk charge to absorption transition<?>. If so, staring in the morning it'll bulk charge untill it hits the absorption threshold, then start the absorption timer.

Is that incorrect?

[booster]

Originally Posted by themexicandoctor

These are my settings on the BMV712 - do they look correct?

Those appear to be the default values, which I don't think are very good.

[booster]

Originally Posted by themexicandoctor

Is that incorrect?

It would normally be the case, but Victron talks about an exception to the it with the solar. It mentions that if another charge source is charging, the absorption time starts as soon as the solar starts up for the day. How often that would be an issue would be based on how the van is used and where it sits overnight. It would be likely to based on battery voltage when the solar comes on, so if it showed any voltage above some arbitrary rested battery maximum, maybe 13.0 volts?, it would go directly to the absorption timer.


If the van sat inside at night, when it was first started, the solar would not be charging because it is inside. When pulled out the alternator would be charging so the solar would go right to absorption timer.


The same could happen if the batteries held a surface charge long enough to still be high enough voltage when the solar next started. I have seen our Lifelines stay above 13.0v for a couple of days.

[@Michael]

Originally Posted by themexicandoctor

Is that incorrect?

The absorption time counter starts once switched from bulk to absorption.

The MPPT Solar Chargers will also end absorption and switch to float when the battery current drops below a low current threshold limit, the ‘tail current’

I have two of the Victron MPPT's, a 100/20 and a 75/15. Here's how I read the manual:

As you are configured, you'll start out in the morning in bulk charge, stay in bulk until your batteries are at 14.4v, then stay in absorption untill either your tail current (2.0A) is reached or your absorption timer is reached (2, 4 or 6 hours depending on how low your battery bank was in the morning).

If anyone interprets this differently, speak out.

Edit:

Originally Posted by booster

It would normally be the case, but Victron talks about an exception to the it with the solar. It mentions that if another charge source is charging, the absorption time starts as soon as the solar starts up for the day.

This is a potential issue then.

The automatic absorption time is based on the start-up battery voltage (see table). This absorption time estimation can be incorrect if there is an additional charge source (eg alternator) or load on the batteries.

Seems like if that condition were to occur, you'd have only 2 hours of absorption.

[themexicandoctor]

Booster,

The vehicle is in darkness at night but no cover ever unless its shadows from buildings & trees.

When you say the default values aren't very good I do understand that default isn't necessarily what is best for every user.

Since you have got me excited about dialing it in for peak performance, what settings do you recommend I change.

[themexicandoctor]

PS. It was set for 6 hours absorption on the MTTP settings, I dialed it down to 4 hours.

And even then, typical absorption time is only 1 hour daily, yesterday was an anomaly at 700 watts solar yield & 2 hours of Absorption time.

[themexicandoctor]

Are there any values that I have set which are glaringly out of whack.

And or should I wait for my install next week & see what happens with the increased load of the fridge which is going to be my biggest power hog?

[themexicandoctor]

Michael,

have two of the Victron MPPT's, a 100/20 and a 75/15.

Why do you have two MTTP's, are you wired in parallel but with two controllers?

[booster]

Originally Posted by themexicandoctor

I do see my Tail Current is set for 2.0amps.

Then below that where it says Battery Monitor I see the ominous figures of charge efficiency at 11%, discharge floor at 11% & state of charge when bulk finished at 11%.

Are these numbers important?

Those numbers are under Battery monitor, so I have no idea where they came from or what they do. I would have to look at the solar manual to know better. It is possible that a lot of the stuff in the Victron components are suited mainly to be used with a centrally controlled system that ties it all together. When used as standalone components a lot of capability is likely lost. The solar can't see the amps going to the battery unless it attached to the shunt, so it can't really know the state of charge of the battery accurately, only guess based on voltage, I think.

[themexicandoctor]

Originally Posted by booster

Those numbers are under Battery monitor, so I have no idea where they came from or what they do. I would have to look at the solar manual to know better. It is possible that a lot of the stuff in the Victron components are suited mainly to be used with a centrally controlled system that ties it all together. When used as standalone components a lot of capability is likely lost. The solar can't see the amps going to the battery unless it attached to the shunt, so it can't really know the state of charge of the battery accurately, only guess based on voltage, I think.

Does this photo help as to whether or not the Solar is attached to the shunt?

[themexicandoctor]

I agree with you about the need for critical fine tuning the default parameters.

For the average person, buying Victron (simply the best product out there), there is so much reference in the manual to how the units will AUTOMATICALLY MAKE THE ADJUSTMENTS that its easy to assume they make all the calculations & act accordingly.

[themexicandoctor]

Just noticed that under the MTTP Presets the EQUALISATION is set to; FIXED

Should that setting be charged to AUTOMATIC, ON VOLTAGE instead?

I do have it set to 4 hours on the Magnum.

And is having Charge Efficiency set to 100% best. I do remember my Mate at Lifeline said "Its ideal for a Lifeline, just like the 15.5 Equalization setting..."

[booster]

Originally Posted by themexicandoctor

Does this photo help as to whether or not the Solar is attached to the shunt?

It doesn't look like it is, but hard to tell.

[booster]

Originally Posted by themexicandoctor

Just noticed that under the MTTP Presets the EQUALISATION is set to; FIXED

Should that setting be charged to AUTOMATIC, ON VOLTAGE instead?

I do have it set to 4 hours on the Magnum.

And is having Charge Efficiency set to 100% best. I do remember my Mate at Lifeline said "Its ideal for a Lifeline, just like the 15.5 Equalization setting..."

Personally, I would not be equalizing all the time, only when needed because of a lot deep discharges, partial recharges etc. Maybe once a month. I would use the Magnum on shore power if it is able to be set properly as that will be a much more consistent power source. Solar can have issues with equalizing as if the batteries take more than the solar is putting out, the voltage can drop and not be effective or stretch out the time too long.

[markopolo]

Originally Posted by themexicandoctor

I do see my Tail Current is set for 2.0amps.

Then below that where it says Battery Monitor I see the ominous figures of charge efficiency at 11%, discharge floor at 11% & state of charge when bulk finished at 11%.

Are these numbers important?

20200717_105723_resized.jpg

I'd assume that they are important. They are not valid entries though and I'm surprised the app populates the fields with them. It happens with the user defined choice.

Screenshot_20200718-114257.png

Spiral AGM preset for comparison:

Screenshot_20200718-114551.png

[booster]

Originally Posted by markopolo

Attachment 9532

I'd assume that they are important. They are not valid entries though and I'm surprised the app populates the fields with them. It happens with the user defined choice.

Attachment 9530

Spiral AGM preset for comparison:

Attachment 9531

Any idea how they could get any kind of accuracy for a battery monitor when they don't know use? Same thing with SOC when bulk ends, which is odd because it moves around with charge rate.

[booster]

Found this in the manual for the solar, I need to check this out.

2 Alternatively, Bluetooth communication can be set up between a BMV-712 battery monitor with battery temperature sensor and the solar charge controller (VE.Direct Bluetooth Smart dongle needed).For more detail please enter smart networkingin the search box on our website.

And here is what you get from doing that search
https://www.victronenergy.com/live/v...art-networking

What they don't say is if the data they transmit to solar controller is actually used to control the controller, as it take it to the tail amps they would get from a smart shunt.


They don't show compatibility yet but show possible future for 12 to 12v chargers and shore chargers.


If the battery monitor could truly control all those devices, it would make for a very nice setup as all of the charge sources, including the alternator could be made to do very good charge control.

[themexicandoctor]

Gentlemen,

I really appreciate everyone walking me through this & for you Booster, keeping me cynical while providing solutions..

Next week I am meeting with My Guru & for a Fee, he is going to go over these threads & then sit down with me & educate me as to the gaps in my knowledge.

I feel like I have everything in place, it looks good but having the fundamentals instilled will give me peace of mind.

In Truth, I represent the 80% of Owners who are sitting Fat, Dumb & Happy.

And from what you are saying Booster, it is possible to have cross communication or its a future feature built in that is not yet available?

[booster]

From the literature I posted, it sure looks like you can have the monitor talk to the solar controller, but it was unclear if the monitor would actually control the charging of the solar.