max battery charge current with mppt and inverter

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saskak asked May 9, '23

max battery charge current with mppt and inverter

Hi all,

I have a small setup with a victron smart shunt 500A (and temp sensor) with victron smartsolar mppt 100/30, 24V battery bank (2x FLA C20 100Ah) and 2x 340W panels connected in parallel.

Currenty I have a non victron victron inverter. My max charge current is set at 20A. I was thinking of getting a few more panels to connect to another 100/30 mppt and altogether in a VE network all tied to rasp3B+.

As the power that I will produce will be quite a bit, so my question is if I get a victron 24V 1200VA inverter, are the MPPTs smart enough to see from the victron inverter the amps drawn and push more current to the battery/inverter above the max charge current. So, a hypothetical example, the solar panels can produce say 25A each (two MPPTs), the battery gets charged with 20A and 30A go to the inverter or will the MPPTs altogether just limit the current going to the battery/inverter at 20A regardless of the inverter load?

Logically in my mind, the VE network should be able to see the victron inverter load and adjust accordingly and push more than the max charge battery current. Maybe it is my wishful thinking.

Many thanks indeed for any help with this.

battery charging MPPT SmartSolar inverter current draw

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Answer 1 · 2023-05-09T10:21:45Z

nickdb answered · May 09, 2023 at 10:21 AM

Smart networking isn't meant to be used in conjunction with a GX/venus device. Attach all the devices via VE BUS/VE direct to the GX/Pi and use DVCC to coordinate charging.

All well documented in the GX manual under the DVCC section.

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saskak commented · May 09, 2023 at 10:26 AM

Many thanks for the reply. They all are connected in a bluetooth smart network and a VE direct cable (MPPT & shunt) to the Pi for logging purposes. I will read on the DVCC to see if the system can push current above the max charge settings to account for the inverter load.

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nickdb ♦♦ saskak commented · May 09, 2023 at 10:31 AM

It's best to not mix and match as it can create conflicts. With a Pi/GX it should all be wired.

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saskak nickdb ♦♦ commented · May 09, 2023 at 10:34 AM

Yes, I can see that, but have not had problems so far, it is a very simple system. If I get another mppt and victron inverter, then yes they will be only wired to avoid problems. Many thanks for the quick reply, it looks that the DVCC will work perfectly as the current will be system-wide and controlled by the GX/Pi bypassing the internal MPPT algorithms.

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thanar saskak commented · May 09, 2023 at 11:27 AM

VE.Smart networking is a completely different thing than connecting all devices to a GX. They also don't mix. At all. Also, Victron inverters do NOT support VE.Smart networking, afaik. So, if you upgrade your system with a Victron inverter, the only way for your setup to work, would be to connect everything to your Rasp, running Venus OS. You should get hold of the proper VE.direct and VE.bus cables and ports for your Rasp.

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saskak thanar commented · May 09, 2023 at 11:32 AM

Yes, currently the MPPT and the shunt are VE.direct to USB cables to the Pi with a venus OS. If I upgrade, probably when not if, the inverter will also be via a VE.direct cable. I should probably delete the smart bluetooth network and only leave them through the VE.direct cables. I have not had a problem, but probably be safe than sorry kind of thing.

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Answer 2 · 2023-05-10T11:22:51Z

bigbadbob76 answered · May 10, 2023 at 11:22 AM

Yes, using DVCC you can limit the total charge current into the battery while also supplying the inverter/loads. just make sure you set the mppt to its maximum current.

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saskak commented · May 10, 2023 at 11:30 AM

Ahh, yes, thanks for that. Just read the DVCC section and the system will take the minimum charge current from the DVCC settings and the MPPT settings. Thus setting MPPT at max will be optimal.

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