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Growatt SPF 3000TL LVM 24V .. output automatic turn off

fchen7

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Aug 1, 2021
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I just started using this All-in-One inverter about a week ago. I learned alot, but still having some issue.

battery bank is 24v 200AH battle born lithium
solar panel is 290w peak, Impp 9.05A, Vmpp 32.v, Voc 38.3v, Isc 9.71A
4 of the above solar panels connect in parallel

In California full sun, I am only getting about 10 to 12amp solar input to the All-in-One. Seems low. My previous MPPT charger (EPEVER MPPT 40A), when connect to 12v battery bank (5 of the battle born lithium in parallel), using same 4 solar panels in parallel. i could easily see 30 to 40 amp charging the battery. Why am i only getting 9 -12 amp now ? Doesn't this Growatt has MPPT built-in ? It does not know how maximize voltage to higher amp ?? Or should i connect the solar panels differently ?

Parameter setting:
#1. SBU
#4. SdS. saving powe disable
#5, USE
#6. LFd. auto restart when overload occur, disabled
#7. EFd. restart when over temperature occur, disabled
#10. Number of seris batteries connected. 2. i can't change this. I do have 4 12v batteries. Connect 2 pair of them in series, than parallel.
#12 22.2v
#13. 26.0v. I am not sure what this one does.
#14. C50
#18. bYd
#19. 28.8v
#20. 27.2v
#21. 21.0v
#22. Sbd

Here is the problem, it's an annoying one. Typical output load is about 180watt. (two fridge, computer, router)

At night, when battery voltage drops below 22.2v, utility take over and start provide load and charging battery at same time. This part is great. After a while, when the battery charges to 25.5v, utility stops provide load and charging, and battery take over again. Then after a while, all of sudden, the load stops. The unit stopped sending power to load. Even when the battery is about 25v. This already happen twice tonight. To restore power, i would have to use rocker on-ff switch to turn it off and on. Then the battery would start supply load again. I am monitoring it now, to maybe see the voltage of battery when it happen again. The load is the same, about 180 watt.

Do you know what's going on ?? I appreciate any advise.

frank
 
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previous MPPT charger (EPEVER MPPT 40A), when connect to 12v battery bank (5 of the battle born lithium in parallel), using same 4 solar panels in parallel. i could easily see 30 to 40 amp charging the battery. Why am i only getting 9 -12 amp now ?
Amperage is going to be lower at higher voltages but the wattage stays the same. Since you have changed the battery voltage that those panels are charging(doubled), you should see half the amperage the previous charge controller was putting into the battery bank with all other variables being the same.

You are however only seeing a quarter of the previous output of those panels using the growatt MPPT which tells us the above is not the complete reason. I suspect that you will see much higher efficiencies if you series(NOT ALL, continue reading) connect those panels and greatly raise the voltage they put out in relation to this new battery bank configuration that they are charging. Those battleborns probably top out at 29ish volts full and your panels configured all in parallel is only outputting ~38volts VOC.

That particular Growatt has a 145 max VOC MPPT input limit if I recall correctly. Reconfiguring your panel array to send a larger voltage to that MPPT charger, but you must remain within it's allowable specifications while taking into account the temperature variable VOC changes with those panels, is going to be a must. I suggest rewiring your current array by creating 2 pairs each pair a series and then wire those strings in parallel to the MTTP. The higher voltage will also reduce the voltage loss from the panels to the charge controller.

Your previous epever SCC would have benefited from a higher voltage series connection as well. If you were using something like the EPever 4210AN. Its "Max PV open circuit voltage:100VDC" taken straight from the amazon product description.

As far as the parameters you listed for the Growatt setup they don't mean a lot to me without the manual in front of me to provide context. The cutting off of the inverter part that you are describing could be a setting that you have configured combined with voltage drop at your batteries current state of charge with insufficient cabling to the inverter while a load is applied.
 
4 of the above solar panels connect in parallel
This is your problem I think.

The Growatt MPPT has a Voc limit of 145V and the MPPT operates in the 30-115V range. You are barely creeping into the low end of the MPPTs operational voltage range with only one panel in series. Being higher up in that range will help the MPPT out.

Try putting your panels in a 2S2P configuration.

3S would be better but you only have 4 panels. If you added 2 panels then 3S2P would be much better and still have plenty of headroom to not exceed Voc when super cold.
 
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