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repro asked

Quattro 48/5000 battery charging only from grid only when solar can't keep up

I have found several threads on this issue, but they don't seem to hit exactly on my issue. I have a Quattro 48/5000 (US 120V version). I have the unit set up for "Self-Consumption" using ESS. I want to use solar power only to power loads and charge the batteries. I do not want to use grid power at all until the solar can't keep up. I have had the "Grid Setpoint" set to "0" zero under ESS in the Console as I thought this would keep grid use off until the batteries hit the 50V set point as set in the ESS Assistant. It did not work.

For 7 weeks now, solar was holding up, and now we have had 5 straight days of total overcast and solar just can't keep up. I want to have grid power charge batteries when the voltage hits 50V, turn off grid power and go back to solar when fully charged. I was told that it was no problem to configure it to do this before purchasing. I hope it really can do this, or else I bought the wrong inverter.

My system is set up as an off grid configuration, and I am not allowed to feedback into the grid. I have grid feedback shut off. I had the grid setpoint set to zero as it was always pulling approxiamately the set value from the grid. I don't want to use any power from the grid unless the batteries get too low.

I have:

Quattro 48/5000/70 120v US version

Two 48V 100Ah LiFePO4 batteries

Six 320W panel array

VE 150/70 Blue Solar SCC

Cerbo GX

MK3 adapter

GX Touch 70

50A grid line in from main box

AC out to Sub panel with 4 20A breakers

Anyone please?

MultiPlus Quattro Inverter Charger
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dennis-van-grol avatar image dennis-van-grol commented ·
Hello,

I have almost the same issue - I don't have the ESS but the rest is the same issue. Grid-tied (oh no the solar isn't enough to charge up the batteries) power kicks on even though there is power left on in the battery bank. I only want the AC in to kick on when the batteries are low.

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nickdb answered ·

Someone else here can advise on automation.

For the rest, grid set point is not a rigid value, it always flexes up and down depending on load. The lower you set it the more it will push back into the grid instead of pulling but it will always do a bit of both.

ESS optimised will provide power exclusively from battery and PV (minus the grid setpoint) until it hits minimum SOC (or active SOC if you use batterylife).

At this point it will prevent battery discharge, service loads from grid and feed all available PV into battery charging, until it gets 5 to 10% above the minimum SOC again.

You can just switch modes to "keep batteries charged" which will use PV for loads and battery but cover all shortages of power (including charging) from the grid.

When you get back to where you want to be, change modes back to optimised.

There are clever ways to try automate this, just depends how technical and software-centric you are.

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repro avatar image repro commented ·
I think I understand. I am thinking that the "Keep Batteries Charged" mode may do the trick. I will try it out. Thanks!
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repro avatar image repro commented ·

I just switched to the "Keep Batteries Charged" mode, and it immediately switched to grid even though the batteries are now fully charged. This setting does not charge the batteries, it only goes into Pass-Thru and will not use the batteries to maintain batteries current SOC. Any other suggestions?

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repro answered ·

Just to experiment with the SOC, I am setting it to 85% to see if that works. My batteries typically drop to 80% overnight and fully charge in 3-5 hours during the day. I will see tomorrow if that worked. Any further input would be appreciated. Thanks!

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pmikep avatar image pmikep commented ·
You might be over thinking this. But you've swerved onto the right track.


But unless you are getting SOC information from a Smart BMV (or other reliable source), your test using SOC as a control parameter won't work correctly. (Because, as you'll find, your Quattro doesn't know how much power Solar has added to your SOC.)

But I am pretty much doing what you want to do with one of my Multiplus's.

I have a Multiplus plugged in to the wall. (It does not have ESS capability. Or, if it does, I don't know anything about ESS. So I don't address ESS here.)

The batteries powering my Multiplus are usually charged up via Solar. But when the batteries are too low, my Multiplus kicks in and charges the batteries to a certain point, and then stops charging.

For this I use the AC Connect setting in Victron Connect. (I am assuming that your Quatro has the same setting in Victron Connect.)

I don't have a Smart BMV, so I can't use SOC to trigger when AC Connects. But I do know the approximate voltage for 25% SOC (trial and error). So I've set my Multiplus to connect to AC if the battery voltage is at - or below - that voltage for more than 5 seconds. (I needed some padding so that a transient load (like a refrigerator compressor starting) wouldn't trip the Multiplus into a too soon charge.)

Likewise, I know the approximate voltage for 30% SOC. So I set that Disconnect voltage to that voltage, with a 15 minute delay. (The delay is needed because voltage is a lousy indicator of SOC, and this delay ensures that I'm above 30%. (Again, trail & error.))

Of course when the Multiplus connects to the grid, then it will pass grid power to my appliances.

You said that you did not want to power appliances from the grid. But if your batteries are low, I don't see how you can not be powering appliances from the grid while you are charging your batteries.

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