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Hi,
I have 44 kWh batteries charged with smart MPPT 450/200 until noon. Then charged my car and dropped battery charge to about 60%, then I expect the MPPT charge my battery again while sun is shining bright.
But does not charge, just shows -15W, which is “standby”. Any idea why the 450/200 does not start charging again?
You are going to need to provide more detail here, and properly document your setup, configuration, and ideally add some vrm charts.
With this little to work on it would require a crystal ball ;)
Hi NickDB,
I am running a 3 x MP 5000/70/48V system with one Smartsolar MPPT 450/200 with 4 strings connected. First screen shows typical charging Szenario, the at 12:00 car connected for charging and at 14:00 disconnect of car and still sunshine. I expect the SmartSolar to start charging again as drawn. But stays in standby mode. My battery system has 50V max. voltage, 42V nominal voltage and 39V min. Voltage (Car battery LiIon from a Ford Mustang Mach E).
the daily cycle works just fine
Typical sunny day with typical charging
Is this a sufficient info for analysis..?
But from the last picture it tries, indeed, to recharge....
Like I've said, see if you can change the behavior from 450/200 config, at Battery - Expert mode - Bulk - Re-bulk voltage offset.
Update: Smart MPPT starts to charge again with a delay of 2 (valuable) hours…
can this be somehow changed…?
How is the battery connected to the system (comms)? Are there any comms, or are you running it unmanaged? Is there a shunt (there should be for this scenario if it isn't managed) and is it configured as the battery monitor?
Are the inverters (all 3) properly configured with a Lithium charge profile?
Are you using DVCC? How has it been configured?
I suspect that probably little of this is configured (hopefully I am wrong), and if that is the case, the chargers have to do some guessing which isn't ideal.
I would also check all the settings on the MPPT and measure (ala meter) that all the devices/battery have the same voltages at their terminals.
It seems you have to find the setting Re-Bulk and make it smaller.
I had in some years ago the same problem with my SOPzS Batteries of 2940Ah.
They are so Voltage stable, that the default Re-Bulk value was set to high.
As an example I have set it for my SOPzS Batteries this way:
1) Equalize 30,6V 2) Absorbtion 29,6V 3) Float 27,6V 4) Re-Bulk 0,4V
I can put a load of 500W on the Batteries and it if I wait for 26,4V (Re-Bulk 1,2V) then my Battery is at SOC 75% roughly. Now it switch from Float to Bulk if the Voltage drop under 27,2V.
