I have a MPPT that can charge 70 Amps.
The Battery can take 50 Amps.
I have an inverter to charge my electric car.
If the MPPT uses the current from the shunt I can set it to 50 Amps and on sunny days the MPPT can deliver 70 Amps. The shunt current protects so that current to battery never exceds 50 Amps.
Can I do this ? If No why not ?
Not with just the MPPT and inverter/charger. The shunt does NOT protect the battery from excessive charging current.
You need a GX device (Cerbo, Eranko, etc.). With that, you enable DVCC and set the max charging current. It then throttles the MPPT and inverter/charger so that the 50 amps is never exceeded, but can use the additional DC power for DC and AC loads.
This can be done with a GX device (such as Cerbo GX) using DVCC. But not sure if it would work with a non-Victron inverter. It might work in this case, but I can't actually test that scenario to confirm.
Have I understood this right?
If I control the inverter manually the Cerbo GX can throttle up and deliver max 70 Amps when the inverter takes 20 Amps or more. The Cerbo GX limits the current to the battery to 50 Amps.
If that is correct I will buy it.
Cerbo GX by itself has no display. You can access the GUI from a web browser connected to the Wi-Fi network Cerbo creates by default, or you can plug in an ethernet cable to your LAN and then connect to venus.local.
The GX Touch 50 and 70 are Cerbo's companion display. The new Eranko has in integrated display.
You can also run Venus OS on a Raspberry PI.
Cerbo will also communicate with Victron connect app on your phone using Bluetooth.
To summarise for clarity.
Victron BMV or smart shunt needed as well as Cerbo GX. BMV and shunts measure/report.
Inverter/charger and solar charger as well as loads and earth are connected to load side of shunt. Only connection to battery neg is the battery side of shunt.
Shunt will then see all current passing through battery and report to Cerbo.
Cerbo will adjust solar charger current only.
So if you set a 70A charge limit and your non Victron charger puts out 50A, MPPT will be throttled back to 20A to limit the battery charge current to 70A. If you have a load on the system at the same time, MPPT output will be 20A plus load current.
This assumes sufficient PV output.
Hello,
there are several possibilities, especially if you can program or create a small circuit yourself:
1. switch off the measured current at the shunt pv module with a relay as soon as the current gets too high and switch it on again when the current is low enough.
2. measure the current with a microcontroller/arduino/esp32 and use it to control the charge controller via vedirect so that the charging current does not reach 50A. To be on the safe side, I would stay at least 10% below the maximum value, since the controller can sometimes go higher than the set value, even if only for a few seconds.
3. use a mini-computer of the ordoid, raspberry pi or other type, but you must also be able to program for this, or get the right programs from someone. luckily i can program something like this myself and when i built my first system with victron components, there was no gx device, so i had no other choice.
4. if there is too much electricity, just burn the electricity, you only need a current-controlled relay or a circuit with power transistors to use up the excess. at 20A and approx. 50V that would be 200W and that would not be a problem for 4 suitable power transistors and with a fan you don't need such a large heatsink.
in that case you can also easily keep the maximum charging current because this regulation can be readjusted within us.
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goodbye
