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Trina avatar image
Trina asked

Direct MPPT Load-Out options?

Hi

I have the 100/15-smart.

I regularly use the direct-load output to recharge small portable things while doing gardening (like tablet and phones and small camping batteries and power banks).

I was under the belief that this output on the smaller MPPT chargers would use "excess" solar power vs taking it direct from the battery.

Is there a function for this that many people use it for like with built-in relay and street-light functions)?

For me I wish it could be monitored by my BMV712 to help me track system usage and would like excess solar to loads so I could charge portable battery devices.

Can it be done with the relays?

Maybe I need to get out my manual and do some more Google-Fu?

MPPT Controllers
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2 Answers
wkirby avatar image
wkirby answered ·

The load output switch acts directly on the battery output, as if connected to the battery terminals directly. Therefore when active, anything connected to the load output terminals will be connected to the battery. There is also a current sensor dedicated to the load output terminals to measure power going out to loads.
If there is enough solar, then the MPPT output will increase proportionately to try and maintain the battery Voltage at the set level for that stage. Battery current should remain much the same, but solar PV current should increase to satisfy the load. The same would happen if you connect something directly to the battery terminals.
Basically, solar energy is always the default source, battery is the second source. There are no settings to change this. So it's a bit curious what you are observing. Would it be possible for you to post some screenshots in order to help us understand what you see?

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Trina avatar image Trina commented ·

Yes.

Now that I am close to done setting up and re-calibrating my BMV correctly I am seeing the PV output in the MPPT increasing to maintain float current while increasing output to power the direct load-out for portable devices.

It seems to be working exactly as stated and per specs.

I believe the issue was incorrect SOC and detection parameters in the BMV feeding info to the MPPT while networked after moving the system.

I can now have complete excess solar being "piped" from the MPPT to direct-loads that will use all my excess solar energy while completely maintaining float charge and current.

With correct calibration of my BMV it also shows correct time-to-go and SOC based on live status.

Wonderful.

After playing with many settings I think I know enough to solve anything on my garden system now with these devices.

I am very happy with Victron gear.

Now all you guys need to do is make better' more rugged wire I/O on the MPPT's so they are 100% competitive with the outback Tracer-BN series solar MPPT controllers which have metal terminals and can handle LARGE wires to the shunt and battery! I hope you development folks win that budget argument as I would upgrade for the bigger wire terminals to at least the battery (say 4/0 or even 6AWG at least)!


Thanks for your time and attention.


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Trina avatar image
Trina answered ·

Might have solved it.

The issue has been that my bmv does not register anything the mppt load-out is using (unless perhaps they are networked) pr simply my loads were too small (headlamps, cellphones).

If I want to see my MPPT load-out draw I have to check it on the app (OR use the shunt). However the MPPT does show it's load-out draw in the app.

Essentially I wind up needing to check both devices for load if I use the load-out on my 100/15-smart.

The BMV712 however once set up correctly does show overall state so that seems to be the solution. Since I wanted to only check the bmv most of the time I was hoping the mppt load-out would use solar first.

I will monitor and post some screenshots if I can't solve or it looks like it's still using battery first and NOT harvesting the excess solar (like the issue I was seeing all last week).

Thanks!

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