eSmart3 Charge Controller Calibration


HUGE range of batteries & accessories at www.batteryhookup.com 5% coupon "POWERWALLS"

rcuetara

New member
Joined
Aug 16, 2019
Messages
6
I have seen many reports of errors in the voltage and current readings of these charge controllers. I want to share with you my experience calibrating them. Unfortunately there is not much documentation available about them, even less about the "hidden" menu in the MyGreenSolar software provided by the manufacturer.

The menu has "ratio" and "offset" parameters for each voltage or current. It is reasonable to think these are somewhat related to the slope and intercept of a calibration line. If that is the case then one would expect a change in the "offset" parameter would cause equal changes in the measurement across a range of values within the 0.1 unit resolution of the devices. Similarly a change in the "ratio" parameter should have larger effects as a value is increased. That is what I found, testing with battery voltage, however the "offset" parameter works opposite the value, increasing "offset" decreases the value. I also found the device accepts negative values for "offset" so if there is a need to increase the value and the "offset" is at 0 it can be done.

Note that I have only tested battery voltage, which in my case is the only important value, and with the 60 AMP model only.

I have worked out the following calibration procedure:
Warning: Don't use the "hidden" menu to do this, It does not seem to work.

1. Apply a low (about 10 to 12 volts) voltage to the battery inputs. Note the voltage difference and write it down, it will be the TARGET.

2. Apply a high (about 50 to 60 volts) voltage to the battery inputs, change the "ratio" parameter until the voltage difference is the TARGET or less.

3. Go back to the low voltage and adjust the "offset" if more than 0.1 volt.

4. Repeat steps 2 and 3 if needed.

I tried this with four devices and only had to change the "ratio".
 

507PowerWall

Member
Joined
Jun 6, 2020
Messages
103
I will be getting 2 of this, probably I will need to come again and review this calibration process
 

not2bme

Member
Joined
Oct 16, 2017
Messages
497
I have two units that are different in voltage by 0.3V. It doesn't bother me at all to bother to 'calibrate' it.. Once you set the correct voltages it just works. Doesn't matter that both have to be the same values as long as the end result is the same. The only thing I'd advise is to tighten the screws. One day I noticed one of my units started acting strange, and that's where I noticed the battery side of the internal cable looks funny. Sure enough it wasn't tight and part of it looked like it's got some burn marks from overheating due to the poor connection. I replaced the wire but it has never been the same since then... it would power off when the current goes too high, possible one of the mosfets must have also conked out. So check all the wires and screws and make sure they're tight.
 

507PowerWall

Member
Joined
Jun 6, 2020
Messages
103
Noted, and thanks for the extra inside of these Esmart3

CG
 

ajw22

Member
Joined
Nov 16, 2018
Messages
664
I have 3 units running in parallel, and calibration is not absolutely necessary. I just compensated by adjusting the target charging voltages of each individual unit.
Eg. the one that reads voltages too low is set to charge to 14.4v, the one that reads high is set to 14.2v, etc. Not perfect, but good enough.

Note that even if you have a "24V" or "48V" volt system, all the configuration voltage values has to be based on a 12V battery system, which esmart3 then internally multiplies by 2x or 4x, depending on the voltages it detects on the battery port.
Eg. If you have a 14s system and want the final charge to be about 4.08V/cell, you have to set the bulk/float/equalize voltages on the esmart3 to 14.3V ( 4.08V * 14 / 4 ; divide by 4 to convert 48V system values down to 12V system values).

+1 on screws. Stranded wires deform/shift and come loose over time. Use ferrules, or solder the tip of the wires so that they do not fray.
Also, check the fans occasionally. One disintegrated after just a few months.
 

507PowerWall

Member
Joined
Jun 6, 2020
Messages
103
ajw22 said:
I have 3 units running in parallel, and calibration is not absolutely necessary. I just compensated by adjusting the target charging voltages of each individual unit.
Eg. the one that reads voltages too low is set to charge to 14.4v, the one that reads high is set to 14.2v, etc. Not perfect, but good enough.

Note that even if you have a "24V" or "48V" volt system, all the configuration voltage values has to be based on a 12V battery system, which esmart3 then internally multiplies by 2x or 4x, depending on the voltages it detects on the battery port.
Eg. If you have a 14s system and want the final charge to be about 4.08V/cell, you have to set the bulk/float/equalize voltages on the esmart3 to 14.3V ( 4.08V * 14 / 4 ; divide by 4 to convert 48V system values down to 12V system values).

+1 on screws. Stranded wires deform/shift and come loose over time. Use ferrules, or solder the tip of the wires so that they do not fray.
Also, check the fans occasionally. One disintegrated after just a few months.

For me the best practica is Solder the strands.... never failed for me at least :)
I indeed have a 14S system you nailed again with this advise :)
Thanks !
 
Top