MPP LV65 Failing Over to Utility When Battery Fully Charged

I have (2) LV6548 in parallel. It's finally getting warmer in Northern Michigan and I kicked on the central air and started noticing this problem.

My inverters are set to Solar/Battery/Utility. I have 10,000 watts of solar and 400ah of 48v batteries.

When my load is higher, I run into this issue. For example earlier today, I had a load of about 5000 watts (higher then usual). Solar was providing about 1/2 the power and the other 1/2 pulling from batteries without issue.

Then my water pump kick on (kids playing with sprinkler outside).

Once this happened, the entire load from that inverter shifted over to grid. Even though the battery was well over 90% charged. It would not shift back.

I finally turned off the breaker for the grid assist. Then it started pulling from battery as desired. Flipped breaker back in and it was fine again, until the well pump went off, then it was stuck on grid again.

It doesn't seem to be respecting the solar/battery/utility setting. I can see it failing over for about 15-20 seconds (when well pump goes off, if pulling from the same inverter exceeding the 6500 watt rating). However, I would think it should fail back to battery if this situation occurs.

Any advise?

Do you have the settings set to auto reset?

It's setting #6, on my Growatt.
Should be somewhere around that on MPP.

Looks like setting 6 is "auto restart when overload occurs". That was disabled (the default). I went ahead and enabled it.

Any idea what a restart consist in? Does the inverter power itself off or just reset itself internally?

Thanks in advance. I would of never thought of that setting.

davesmith87 said:

Looks like setting 6 is "auto restart when overload occurs". That was disabled (the default). I went ahead and enabled it.

Any idea what a restart consist in? Does the inverter power itself off or just reset itself internally?

Thanks in advance. I would of never thought of that setting.

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Should just revert back to battery.

It's generally recommended to leave it disabled.
If unattended, it could cycle back and forth over and over. But, just see how it goes for your situation.

timselectric said:

It's generally recommended to leave it disabled.
If unattended, it could cycle back and forth over and over. But, just see how it goes for your situation.

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Will do. Thanks for the quick assistance.

timselectric said:

It's generally recommended to leave it disabled.
If unattended, it could cycle back and forth over and over. But, just see how it goes for your situation.

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I think this might be the right thread to bring this up. . I have a similar situation where I don't fully understand the "overload bypass" and "overload restart" options on my split phase lv6548 setup.

My use case: I have "back to battery" setting at 53v and "back to grid" set to 50v. As expected when a larger load (dryer, AC, etc.) kick in, voltage drops and if it gets to that 50v it will kick in to grid to support. After the load lessens and the voltage is recovers back above 50v, the battery typically becomes the source of energy (or solar does that job during a sunny day). I run SBU and "solar only" for charging on both inverters.

For some reason, grid continues to charge the battery (sometimes even past 53v) with these settings. I'm grateful I have that option, but when I know a sunny day is coming tomorrow I'd rather not charge my batteries with grid, and only have to use grid to power my loads until the next morning.

Any ideas?

jibberishballr said:

I think this might be the right thread to bring this up. . I have a similar situation where I don't fully understand the "overload bypass" and "overload restart" options on my split phase lv6548 setup.

My use case: I have "back to battery" setting at 53v and "back to grid" set to 50v. As expected when a larger load (dryer, AC, etc.) kick in, voltage drops and if it gets to that 50v it will kick in to grid to support. After the load lessens and the voltage is recovers back above 50v, the battery typically becomes the source of energy (or solar does that job during a sunny day). I run SBU and "solar only" for charging on both inverters.

For some reason, grid continues to charge the battery (sometimes even past 53v) with these settings. I'm grateful I have that option, but when I know a sunny day is coming tomorrow I'd rather not charge my batteries with grid, and only have to use grid to power my loads until the next morning.

Any ideas?

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I wouldn't expect it to charge from the grid at all. If it's set to only charge from solar.
Maybe you will have to set AC charging to zero.

timselectric said:

I wouldn't expect it to charge from the grid at all. If it's set to only charge from solar.
Maybe you will have to set AC charging to zero.

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I have grid charging to the lowest setting of 2A but it seems to ignore that

jibberishballr said:

I have grid charging to the lowest setting of 2A but it seems to ignore that

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Seems odd to me. But I'm not familiar with every detail of that unit.
A Chargeverter would solve the issue. But that's more money spent.

timselectric said:

Seems odd to me. But I'm not familiar with every detail of that unit.
A Chargeverter would solve the issue. But that's more money spent.

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I'll keep messing around. Maybe a setting isn't sticking or reverting somehow. Can you explain to me those two overload settings? Just want to ensure I'm understanding what they are supposed to do.

jibberishballr said:

I'll keep messing around. Maybe a setting isn't sticking or reverting somehow. Can you explain to me those two overload settings? Just want to ensure I'm understanding what they are supposed to do.

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Overload bypass, means that it switches to grid when the loads exceed its output rating.
Overload restart, means that it will automatically restart after it shuts down (with no grid available) due to exceeding its output rating.

Have a look at program 16. (Charger source priority) default is snu (solar and utility). Try CSO (solar first).
If that doesn’t work, try a complete power down to reset. If you are using Solar Assistant and the micro USB port, pull those before power down and plug back in last after restart. To de power, cut grid, PV, depress both off buttons, wait for it to power down, then open battery contacts and wait for 5 minutes. Restart in reverse order but pre charge the inverters.

timselectric said:

Overload bypass, means that it switches to grid when the loads exceed its output rating.
Overload restart, means that it will automatically restart after it shuts down (with no grid available) due to exceeding its output rating.

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Got it. So this should not have anything to do with switching back and forth between battery and grid.

Skypower said:

Have a look at program 16. (Charger source priority) default is snu (solar and utility). Try CSO (solar first).
If that doesn’t work, try a complete power down to reset. If you are using Solar Assistant and the micro USB port, pull those before power down and plug back in last after restart. To de power, cut grid, PV, depress both off buttons, wait for it to power down, then open battery contacts and wait for 5 minutes. Restart in reverse order but pre charge the inverters.

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I usually set to OSO solar only but have done CSO in the past. Shouldn't OSO be the correct option? When I look at the inverters these settings(16 and all of the other voltage ones) look accurate but I do notice that on solar assistant sometimes they look different (E.g it will show utility first even when the inverter is set to sbu). I've done a full power down before but I'll give it another try and see if that changes anything.

How much total output amp limit do you have from your batteries bms , could the surge be making the bms shut the batteries down. thus switching to grid ?

jibberishballr said:

I usually set to OSO solar only but have done CSO in the past. Shouldn't OSO be the correct option? When I look at the inverters these settings(16 and all of the other voltage ones) look accurate but I do notice that on solar assistant sometimes they look different (E.g it will show utility first even when the inverter is set to sbu). I've done a full power down before but I'll give it another try and see if that changes anything.

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I’ve done a shut down a couple of times. I don’t think I’ve ever owned something that has micro processors that didn’t need to have a little time out.

jibberishballr said:

Got it. So this should not have anything to do with switching back and forth between battery and grid.

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Only if it's overloaded.

jibberishballr said:

I usually set to OSO solar only but have done CSO in the past. Shouldn't OSO be the correct option? When I look at the inverters these settings(16 and all of the other voltage ones) look accurate but I do notice that on solar assistant sometimes they look different (E.g it will show utility first even when the inverter is set to sbu). I've done a full power down before but I'll give it another try and see if that changes anything.

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What does your Solar Assistant show for inverter one ? If you are using SA to change states and it is not showing inverter one as the unit you have as master there could be some issues.