eSmart3 MPPT Setup and Programming

MisterSmolFarm

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Mar 26, 2021
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2
Hi everyone. As per thread title, I want to have some information regarding the setup and programming of the eSmart3 MPPT controller.

Background:
My dad bought a piece of land with a house a while ago, and the house came with big off-grid solar system, 3 Axpert 5Kva inverters in parallel, single phase and those very expensive Willard 2v cells making up 3 banks of 48V.
As he got someone professional in to look at this system, the tech told him that the batteries should be "equalized" to 60V once every month. But the Axpert inverters is not capable of charging the banks to the required 60V.

He invested into two eSmart3 MPPT charge controllers, thinking he can program them with a user interface to equalize the banks to 60V every month.
It seems to not be the case? after he contacted me, and I came for a visit to have a look at the newly installed MPPTs, because the guy who installed them, are not capable of programming them, he just installed it and left.
Now, since I am the only guy in the family who does this sort of things, I need to set up my dad in a way so that he can equalize charge the banks whenever he get full sun and when the inverters can be turned off/disconnected for a while.
Like an on-demand equalize charge.

Questions:
1. From what I have seen on the forum, I have to set the float voltages and such to what they need to be, as if it was a 12v system, dividing the values by 2/4 depending on the battery voltage (24 or 48, so for example 54V float voltage divided by 4 gives 13.5V) -> is this correct?
2. How do one set up the equalize stuff? Do you need to set the equalize voltage (again in 12v terms, 60v -> 15V) and set the equalize charge time to 0? The equalise time, is it in hours, minutes?
2.1 When does the equalize happen? Every first day of the month (according to the manual it seems) and it happens during the "Constant Voltage" charge stage?
2.2 What is the maximum time that you can set on the boost/equalize stage?

I have done protocol sniffing a while ago, (modbus, DLMS, the like) and integrated with the Axpert inverters using the Blynk platform (That is another story for another day), I figured it would not be so difficult to set up a sniffing session on one of those controllers, and use the MyGreen application to sniff the bytes and messages.
I will maybe link up an Arduino with an RS-485 module that will do the communications and configuration, so that my dad can just press the button, and the equalize charge is enabled/disabled.
 

ajw22

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Nov 16, 2018
Messages
574
Willard 2v cells making up 3 banks of 48V.
As he got someone professional in to look at this system, the tech told him that the batteries should be "equalized" to 60V once every month. But the Axpert inverters is not capable of charging the banks to the required 60V.
Those are Lead Acid cells for sure. And yes, Lead Acid batteries should be "equalized" (essentially, controlled slight overcharging) periodically to make sure that any sulfur deposits in all cells get fully dissolved back into the acid. Otherwise the lingering sulfur deposits will crystallize over time and irreversibly reduce the battery capacity and performance.
Axpert Inverters currently on sale advertise support for battery equalization. Are you absolutely sure yours do not?

Questions:
1. From what I have seen on the forum, I have to set the float voltages and such to what they need to be, as if it was a 12v system, dividing the values by 2/4 depending on the battery voltage (24 or 48, so for example 54V float voltage divided by 4 gives 13.5V) -> is this correct?
2. How do one set up the equalize stuff? Do you need to set the equalize voltage (again in 12v terms, 60v -> 15V) and set the equalize charge time to 0? The equalise time, is it in hours, minutes?
2.1 When does the equalize happen? Every first day of the month (according to the manual it seems) and it happens during the "Constant Voltage" charge stage?
2.2 What is the maximum time that you can set on the boost/equalize stage?
I use 3x eSmart3 chargers configured with the PC Software, but I have LithiumIon batteries that do not require any equalizing, so I'm mostly just quoting the manual:
1. Yes, the eSmart3 internally multiplies all input voltage values by 1, 2 or 4, depending on the detected system voltages of 12V/24/48V.
2. I think the equalize time setting is in minutes, default 60. Value of "0" here might mean "do not equalize at all".
2.1. Equalization (they sometimes call it "boost") is performed on the 1st of each month. During the "Constant Voltage" stage, the higher voltage is applied instead of the regular voltage. I guess after the set time, it progresses to the float stage.
2.2. Just try entering a large but reasonable number?

Don't forget to hit the "apply" button next to each value you change.
My eSmart3 current/voltage sensors were not well calibrated, so that I had to specify slightly different values in my 3 chargers. Measure the actual voltages with a good multimeter.
 
Last edited:

MisterSmolFarm

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Joined
Mar 26, 2021
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Those are Lead Acid cells for sure. And yes, Lead Acid batteries should be "equalized" (essentially, controlled slight overcharging) to make sure that any sulfur deposits in all cells get fully dissolved back into the acid. Otherwise the lingering sulfur deposits will crystallize over time and irreversibly reduce the battery capacity and performance.
Axpert Inverters currently on sale advertise support for battery equalization. Are you absolutely sure yours do not?


I use 3x eSmart3 chargers configured with the PC Software, but I have LithiumIon batteries that do not require any equalizing, so I'm mostly just quoting the manual:
1. Yes, the eSmart3 internally multiplies all input voltage values by 1, 2 or 4, depending on the detected system voltages of 12V/24/48V.
2. I think the equalize time setting is in minutes, default 60. Value of "0" here might mean "do not equalize at all".
2.1. Equalization (they sometimes call it "boost") is performed on the 1st of each month. During the "Constant Voltage" stage, the higher voltage is applied instead of the regular voltage. I guess after the set time, it progresses to the float stage.
2.2. Just try entering a large but reasonable number?

Don't forget to hit the "apply" button next to each value you change.
My eSmart3 current/voltage sensors were not well calibrated, so that I had to specify slightly different values in my 3 chargers. Measure the actual voltages with a good multimeter.
Hello, thank you for the information,
I have a good multimeter on hand, so that's sorted. :)
I am 90% certain that these inverters do not have the battery "equalization", they are at least 5 years old. The one is an SOL-I-AX-5M, the other PIP 4048MS.
I am not aware of any setting on them that I can set the equalization voltage or date on these things.
As for the equalization, I will set my computer's time to the first of march, and sync the time. Then set the voltages and measure with my good AC/DC clamp multimeter.

Thank you, I will report back soon.
 

ajw22

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Joined
Nov 16, 2018
Messages
574
I will maybe link up an Arduino with an RS-485 module that will do the communications and configuration, so that my dad can just press the button, and the equalize charge is enabled/disabled.
If you're going to all that trouble, you might just let the Arduino monitor the battery voltage for the last 30 days or so, and figure out exactly how long the batteries spent at the 60V equalization voltage. If it's deemed insufficient (not enough sun, inverters constantly drawing power, etc), it can automatically reset the inverter date to the 1st for more equalization time. Zero need for manual intervention.

Too frequent strong equalization is certainly not good either... something about the metal inside flaking off.
Quick google shows many sites suggesting a more frequent equalization at just 14.4V - I guess it also depends on the exact battery type.

Much more important than equalization: make sure the Lead Acid cells are properly refilled with _distilled_ water! And wear eye and hand protection.

When the Lead Acid batteries inevitably degrade beyond usable capacity, you should look into Lithium Iron Phosphate (LiFePO4) batteries. Much less hassle, and better value due to much longer lifespan.
 
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