settings on the victron MPPT solar and 712 Battery monitor

[NEWYORKHILLBILLY]

I am setting up my newly installed victron MPPT smarty solar controller and 712 smart battery monitor . I just want to make sure I get this set up properly . There is a few settings that I am not sure I have correct. I have the EFT installed pair of 6 volt Batteries . Interstate emailed me these specs.
Charging specs
Bulk = 14.8
Absorption=14.8
Float 13.2
Equalization= 15.6

Equalization 4-6 weeks


I attached 4 screen shots the first two are from the 712 monitor and the last tow from the MPPT controller.charged voltage? I was not sure what to set the temp coefficient on the 712 and the Temp compensation on the controller at? I just left the value that showed up in the app. Also should I set it for auto Equalization or do it manually?

[fudge_brownie]

What are the descriptions (model) of the Interstate batteries?

[NEWYORKHILLBILLY]

Originally Posted by fudge_brownie

What are the descriptions (model) of the Interstate batteries?

GC2-ECL-UTL

https://www.interstatebatteries.com/...ts/gc2-ecl-utl

[Effie]

I have a very similar system, did you get the optional temp sensor for the 712?

[NEWYORKHILLBILLY]

Originally Posted by Effie

I have a very similar system, did you get the optional temp sensor for the 712?

Yes I did get the optional temp sensor. I figured with the batteries in the Front storage box it would be a must for cold weather.I really lost on what to set the temp coefficient on the 712 and the Temp compensation on the controller at. I think the other stuff I have correct.

[Effie]

I’ve got a very similar system for over a year now with the Escape installed 6v lead acid batteries. I hope this attempt to explain is not terribly confusing.

I’ll start with temp setting, the one on the 712 is going to use the temperature to calculate the state of charge you see in the display, since the 712 is “just” a monitor it has no influence on how the battery is being charged. This next paragraph is from the 712 manual

Temperature coefficient This is the percentage the battery capacity changes with temperature, when temperature decreases to less than 20°C (above 20°C the influence of temperature on capacity is relatively low and is not taken into account). The unit of this value is “%cap/°C” or percent capacity per degree Celsius. The typical value (below 20°C) is 1%cap/°C for lead acid batteries, and 0,5%cap/°C for Lithium Iron Phosphate batteries. Default Range Step size 0%cap/°C 0 – 2%cap/°C 0,1%cap/°C __________________________________________________ ________
The temperature compensation setting on the MPPT will actually increase charging voltage as temps go below 20c and decrease on temps above 20c. Every battery chemistry requires its own settings.

But before using any temperature setting effectively you need to install the optional Victron temp sensor for your 712 monitor and then setup what Victron is calling “VE.Smart networking” a Bluetooth wireless network between the 712 and the MPPT charge controller. Using this wireless communication the MPPT charger receive not only the temperature but also an accurate voltage as measured by the 712, not influenced by wiring between the controller and the battery. The battery current is also transmitted to the controller, probably needed when charging using multiple charge controllers.

Another note on the temperature sensor, if you don’t use it or don’t set the VE.Smart networking, your Victron MPPT controller will use its own internal temp sensor, if not installed in the same area as the batteries (as in most Escape 19) the temp reading at the controller is going to be very different from the batteries temperature.

Now after all this, many charging systems don’t compensate for temperature when dealing with lead acid. As a side note, I noticed in my system that the batteries can reach over 120f in the sun when the outside temp is under 80f (I still don’t understand who came up with the black battery box, but that’s a different discussion)

The pictures below show my 712 VE.Smart networking setup, the two left are the 712 (note the small icon at right above the battery percentage circle, indicating VE.Smart), the third is from the MPPT controller.

When it comes to charging voltage I’ve seen recommendations from 14.4 to 15.00 in bulk and 13.2 to 13.6 for float, I run 14.5 and 13.5.

Equalization, I run it twice manually but this is one area I didn’t explore much

[fudge_brownie]

Originally Posted by NEWYORKHILLBILLY

GC2-ECL-UTL

https://www.interstatebatteries.com/...ts/gc2-ecl-utl

These appear to be a new model for Interstate. There is almost no information about them. I am questioning the charging rates. The absorption rate of 14.8 does not fit with a bulk rate of 14.8. They should be different.

The prior model of these batteries had an absorption rate of 15.4. I cannot offer any documentation to that. I believe there is a mistake in someone’s number. Interstate always had high charge rates (as did Trojan). This can be seen with the equalization rate of 15.6.

[NEWYORKHILLBILLY]

Originally Posted by Effie

I’ve got a very similar system for over a year now with the Escape installed 6v lead acid batteries. I hope this attempt to explain is not terribly confusing.

I’ll start with temp setting, the one on the 712 is going to use the temperature to calculate the state of charge you see in the display, since the 712 is “just” a monitor it has no influence on how the battery is being charged. This next paragraph is from the 712 manual

Temperature coefficient This is the percentage the battery capacity changes with temperature, when temperature decreases to less than 20°C (above 20°C the influence of temperature on capacity is relatively low and is not taken into account). The unit of this value is “%cap/°C” or percent capacity per degree Celsius. The typical value (below 20°C) is 1%cap/°C for lead acid batteries, and 0,5%cap/°C for Lithium Iron Phosphate batteries. Default Range Step size 0%cap/°C 0 – 2%cap/°C 0,1%cap/°C __________________________________________________ ________
The temperature compensation setting on the MPPT will actually increase charging voltage as temps go below 20c and decrease on temps above 20c. Every battery chemistry requires its own settings.

But before using any temperature setting effectively you need to install the optional Victron temp sensor for your 712 monitor and then setup what Victron is calling “VE.Smart networking” a Bluetooth wireless network between the 712 and the MPPT charge controller. Using this wireless communication the MPPT charger receive not only the temperature but also an accurate voltage as measured by the 712, not influenced by wiring between the controller and the battery. The battery current is also transmitted to the controller, probably needed when charging using multiple charge controllers.

Another note on the temperature sensor, if you don’t use it or don’t set the VE.Smart networking, your Victron MPPT controller will use its own internal temp sensor, if not installed in the same area as the batteries (as in most Escape 19) the temp reading at the controller is going to be very different from the batteries temperature.

Now after all this, many charging systems don’t compensate for temperature when dealing with lead acid. As a side note, I noticed in my system that the batteries can reach over 120f in the sun when the outside temp is under 80f (I still don’t understand who came up with the black battery box, but that’s a different discussion)

The pictures below show my 712 VE.Smart networking setup, the two left are the 712 (note the small icon at right above the battery percentage circle, indicating VE.Smart), the third is from the MPPT controller.

When it comes to charging voltage I’ve seen recommendations from 14.4 to 15.00 in bulk and 13.2 to 13.6 for float, I run 14.5 and 13.5.

Equalization, I run it twice manually but this is one area I didn’t explore much

Thank you for the detailed explanation This is good info. I have the net work set up . attached a photo I still have to figure out the correct temperature compensation setting on the MPPT . AM solar has a recommendation for lead acid . But these vaules will not go into the app as they say they do. I think its a older version .
MPPT https://static1.squarespace.com/stat...or+Flooded.pdf
712 https://static1.squarespace.com/stat...%2BFlooded.pdf

Originally Posted by fudge_brownie

These appear to be a new model for Interstate. There is almost no information about them. I am questioning the charging rates. The absorption rate of 14.8 does not fit with a bulk rate of 14.8. They should be different.

The prior model of these batteries had an absorption rate of 15.4. I cannot offer any documentation to that. I believe there is a mistake in someone’s number. Interstate always had high charge rates (as did Trojan). This can be seen with the equalization rate of 15.6.

Hmmm I wonder if they made a mistake? there specs attached

[Effie]

The -54mv/f seems high, usually what you see for lead acid is around -30mv/f, I noticed the default in my Victron controller is -29.16mv/f, but I found the the highest value the app excepted was -54mv/f.

[NEWYORKHILLBILLY]

Originally Posted by Effie

The -54mv/f seems high, usually what you see for lead acid is around -30mv/f, I noticed the default in my Victron controller is -29.16mv/f, but I found the the highest value the app excepted was -54mv/f.

I finally figured out how to get the app into Fahrenheit. I also think the -54mv/f seems far from the default setting. I will send Interstate a email and see what they say. I like to get this one correct as i camp a lot in below freezing weather.

[NEWYORKHILLBILLY]

Originally Posted by fudge_brownie

These appear to be a new model for Interstate. There is almost no information about them. I am questioning the charging rates. The absorption rate of 14.8 does not fit with a bulk rate of 14.8. They should be different.

The prior model of these batteries had an absorption rate of 15.4. I cannot offer any documentation to that. I believe there is a mistake in someone’s number. Interstate always had high charge rates (as did Trojan). This can be seen with the equalization rate of 15.6.

I did question Interstate on this. this is what they said"The charging voltage for the GC2 batteries is correct with the 14.8v on both Bulk and Absorption. These batteries are antimony chemistry so the first stage of charge will be a constant current and the absorption will be a constant voltage with amperage tapering off and going into a float stage of charge which is lower with minimal, if any, current."

Originally Posted by Effie

The -54mv/f seems high, usually what you see for lead acid is around -30mv/f, I noticed the default in my Victron controller is -29.16mv/f, but I found the the highest value the app excepted was -54mv/f.

I trying to research this more.I am sure Victron put the default at -19mv/f for a reason. On the other hand AM solar has a great reputation and seem to know what there doing.It makes me wonder why they would recommend -.54.0mv/f