Growatt?

Cancerfood said:

What batteries are you connecting to the growatt and how are you going to connect the battery bms to talk to the Growatt? I am looking at the same unit but not clear about the bms piece. It states that The growatt will take a rs 45 com link to manage a battery system.

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48V LiFePO4 Powerwall​

$1,899.99

Made with NEW A123 LiFePO4 Cells!​

This is what I decided on, I'm only getting 1 to start with..

smoothJoey said:

It probably is 20 Ms.
About 1 cycle of alternating current.

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This might be a reason that my 12Kw Growatt crashes sometimes my 2 hp water pump started (with only 2-3 K Watt of all other load).

Cancerfood said:

What batteries are you connecting to the growatt and how are you going to connect the battery bms to talk to the Growatt? I am looking at the same unit but not clear about the bms piece. It states that The growatt will take a rs 45 com link to manage a battery system.

Click to expand...

I am using Lishen 272Ah LiFePO4 batteries, 16 in series. Still waiting 9n delivery. I bought Daly 300 amp BMS units. No need to connect the BMS to the charge controller in the Growatt. I will maybe add a second battery at some point as well.

mad.styles said:

Does the growatt require a bms communication in order for it to work?

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No

Well, i have the inverter and sub panel installed, just need to install the outside AC emergency disconnect. Still waiting for the 20 cells I ordered, been almost 7 weeks, they say they are all backed up at the port, coming FedEx once they are liberated from the import warehouse. The BMS wants to get to work!

Ed Mek said:

This might be a reason that my 12Kw Growatt crashes sometimes my 2 hp water pump started (with only 2-3 K Watt of all other load).

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That seems concerning... my admittedly quick search for start up consumption of 2hp water pumps seems to indicate a punctual need for about 7500 watts... If you're sure the rest of your load is max 3k watts when the Growatt spits the dummy, then it would appear it might be struggling to even deliver 12kW ?

mzoid said:

That seems concerning... my admittedly quick search for start up consumption of 2hp water pumps seems to indicate a punctual need for about 7500 watts... If you're sure the rest of your load is max 3k watts when the Growatt spits the dummy, then it would appear it might be struggling to even deliver 12kW ?

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This is most likely why they are listing the 36kW surge rating at only 20ms. If you look at other inverters like those made by Victron they have more realistic/useful information "readily" available such as this post: https://community.victronenergy.com...e-peak-output-current-or-maximum-surge-a.html
and a really good video by Victron on inverter overload: https://community.victronenergy.com...e-peak-output-current-or-maximum-surge-a.html

It's also concerning that the spec sheet for the Growatt doesn't mention idle current either. These are two red flags for me that they choose not to list this and are lacking useful overload capacity specs.

Edit: Note how Magnum inverters list the overload capacity in 1ms, 100ms, 5s, 30s, 5m, 30m https://www.magnum-dimensions.com/s...S-PAE-series_datasheet_64-0275_RevE_web_0.pdf

Update:
After 1 year of daily inverter shutdown, it's finally solved. The problem is a bug in the old firmware.
AFter a firmware update, there is no crash and the inverter can handle 8+kW a sustained load. It can start 4 ton AC along with 4 kW background load without any issue.

Here is How-to Video

Signature Solar Explains the Firmware Update for Growatt Off Grid Inverters.
NOTES! -
Shut Off the AC breaker before flashing firmware
-If firmware flash fails disconnect PV, AC and Battery from the unit and wait for 10 minutes
-Consider that you may need to replace the USB cable you are using as it may be faulty

THE BOOTLOADER AND USB DRIVER LINK: https://drive.google.com/file/d/12bLe...

THE FIRMWARE FILES FOR ALL GROWATT OFF GRID INVERTERS (UPDATED REGULARLY):
Currently only specific products have available firmware updates available.
If you do not see a file for your inverter, please do not attempt to update firmware. If you have any questions, please contact Signature Solar. https://drive.google.com/drive/folder...

rhino said:

This is most likely why they are listing the 36kW surge rating at only 20ms. If you look at other inverters like those made by Victron they have more realistic/useful information "readily" available such as this post: https://community.victronenergy.com...e-peak-output-current-or-maximum-surge-a.html
and a really good video by Victron on inverter overload: https://community.victronenergy.com...e-peak-output-current-or-maximum-surge-a.html

It's also concerning that the spec sheet for the Growatt doesn't mention idle current either. These are two red flags for me that they choose not to list this and are lacking useful overload capacity specs.

Edit: Note how Magnum inverters list the overload capacity in 1ms, 100ms, 5s, 30s, 5m, 30m https://www.magnum-dimensions.com/s...S-PAE-series_datasheet_64-0275_RevE_web_0.pdf

Click to expand...

Ed Mek said:

This might be a reason that my 12Kw Growatt crashes sometimes my 2 hp water pump started (with only 2-3 K Watt of all other load).

Click to expand...