Power going into house battery during EV charging

Q&A and troubleshooting EVCS
1

Hi Community,
I have an off-grid system with an EVCS NS charging station. The way the system works at the moment is that, once it starts charging the car, it only puts about 200-300W of power into my house battery. I wanted to ask if anyone knows if there’s a way that I can increase this? Couldn’t see anything in the UI, but I saw some values in the TCP register list that might do this? Eg:

5085 ‘Battery powered’. BKPB power threshold for decrease 250W

Any tips would be appreciated.
Cheers,
Helmut

2

How much extra solar power do you have? Ideally, that would ramp up and charge both the car and your house battery.
Are you off or on grid? What is the rest of the system?

3

I have a fair bit of solar - 10kW. As mentioned in my post, I am off grid. 10kVA inverter. In Auto mode, the EVCS provides around 250W of power to the house battery (it alternates above and below that given the integer Amp nature of the power going to the car).
That’s why I thought perhaps that register value (or some other similar one set to 250W) might control that.
Cheers,
Helmut

4

You can use my node red auto ev charger if you have a cerbo gx. It has dynamic inputs to charge the house battery depending on state of charge, which you can adjust.

5

Hi Craig - not sure I follow. Are you suggesting using a different EV charger altogether? Because I don’t want to do that since I’ve already got the Victron EVCS installed.
I just need a better definition of the various TCP register parameters.

6

No. It just uses node red in the Cerbo GX to control the charge rate of the EVCS such that it gives you a dynamic house battery charge setpoint based off the state of charge of your house battery.

if (soc < 90) {
        setpoint = initialsetpoint || 450; 
    } else if (soc >= 90 && soc < 96) {
        setpoint = 300; 
    } else if (soc >= 96 && soc <= 98) {
        setpoint = 40; 
    } else if (soc > 98 && soc < 100) {
        setpoint = 0; 
    } else {
        setpoint = -150;
    }

You can change those numbers to suit your system and depth of discharge overnight.

7

Interesting. Is there documentation for these parameters somewhere?

8

There isn’t. I can’t code my way out of a wet cardboard box, so AI did the coding. If you have any questions, I would suggest copy pasting into AI for assistance.

If you think there’s a fatal flaw or it’s not operating the way you think it should, I can assist.

9

Does anyone know what kind of memory these TCP registers are stored in? Is it stored in NVM or RAM? And if stored in NVM, do the registers have a wear out mechanism (ie max number of write cycles)?

Thanks