Growatt SPF5000es cuts out no fault code

[TheYeti]

hello all,
New to solar so be gentle. I have recently installed a Growatt SPF5000es powered by the Hope Growatt 4.8kw lithium battery connected via BMS and 3000 watts of solar. It ran fine for a couple of weeks but now will randomly shut off completely and restarts around 2 minutes later with no fault codes present. Im finding it does it during daylight hours but doesn't seem to matter if its sunny or overcast. a few times it has failed to restart and i have to switch it off and restart the battery then the unit. Im well inside the charging parameters producing around 200 volts at 6 to 10 amps. Ive reached out to Growatt here in Australia a few time and dont get a responce. Any help would be greatly appreciated as ive been looking everywhere but not found anyone with a similar issue

 

[timselectric]

Are your loads going high enough to trip the system. I'm not familiar with that battery. Does it automatically reset after an overload? Can you access battery logs?

 

[TheYeti]

Are your loads going high enough to trip the system. I'm not familiar with that battery. Does it automatically reset after an overload? Can you access battery logs?

Ive seen it referred to in here as using a sledgehammer. system is running basic stuff like fridge tv and chargers sits around 400 watts with the basics on as its only running a shack and not a conventional house.
yeah 90% of the time it will just turn itself back on after around two minutes, even though I have auto restart disabled in the settings. the other 10% I have to physically turn off the inverter, start the battery and turn the inverter back on. When it comes back on it will beep and give me I think fault code 4 until the battery regains coms with the unit but i think that is normal in start up. I have no access to battery logs

 

[TheYeti]

Just added a picture and circled, from what have read over the last week may be potential issues. The larger circle is the AC breaker box but I have also included a DC breaker inside for the PV input, can AC and DC being this close together mess with each other?
The smaller circle is a DC breaker and its from Fleabay but it has never tripped so not sure but maybe thinking its the wrong component for a two way flow?

 

[timselectric]

Yes, until communications is restored. It would think that the battery is low. (Fault code #4)

 

[timselectric]

can AC and DC being this close together mess with each other?

No, that should be fine.

The smaller circle is a DC breaker and its from Fleabay but it has never tripped so not sure but maybe thinking its the wrong component for a two way flow?

Some of these types of DC breakers are not rated correctly.
I wouldn't trust them, unless they are a well known brand.

 

[Vigo]

I have not seen those style of dc breaker rated over 42v dc. If there are higher rated ones id probably pick one up!

 

[TheYeti]

just to continue on this thread. with some research and no help from growatt i think i may have chosen the wrong solar panels. i went with 12 volt but i think the amps are exceeding what the battery can handle (not the inverter) for some reason with my current set up in setting 2 my amps are set at 16amps and im not sure whats limiting this setting? the only thing i can think of is changing out the panels for higher volt lower amps

 

[timselectric]

The amperage from the solar panels are controlled by the SCC. I have 36a worth of solar panels connected to the same inverter. The SCC will never pull that much, it limits itself to 17.6a. The panels don't push power. They just make it available. The SCC draws what it needs. If you have BMS communications hooked up, the BMS controls the charging amperage. You can't change that.

 

[TheYeti]

The amperage from the solar panels are controlled by the SCC. I have 36a worth of solar panels connected to the same inverter. The SCC will never pull that much, it limits itself to 17.6a. The panels don't push power. They just make it available. The SCC draws what it needs. If you have BMS communications hooked up, the BMS controls the charging amperage. You can't change that.

Thanks for your reply. I did read that it should only take what it needs regarding amps. i have noticed that the issue only occurs when the panels are exposed to the sun abruptly, ie. when the sun comes out from behind a cloud. the input amps will only hit around 10 but the amps displayed under the batter will keep climbing and shuts off around 20 amps with a battery fault. any reason why the amps displayed under the battery are around double what the input reading is ever when there is no AC load? this thing has me so confused

 

[timselectric]

The solar amperage is different from the battery charging amperage. Because of the voltage difference and efficiency losses.

 

[timselectric]

It kinda sounds like the battery BMS is shutting down. Due to a single cell going too high. Do you have a way to see BMS data? To see if the cells are balanced.

 

[Vigo]

If the battery bms is disconnecting the battery at ONLY 20amps or so, you have a big problem with the battery. The inverter is probably shutting off due to over-voltage on the battery circuit because when you are charging a battery, the battery itself is what is 'holding down' the voltage of the charge source to be whatever it is while the charge source is trying to raise it. If the battery suddenly disconnects, the charge source voltage will shoot up, and the inverter may shut itself down in 'overvoltage protection mode' or whatever it's called, before it actually responds to the condition by lowering charging voltage.

It is sort of like if you are pulling up real hard on one of those exercise bands and it slips and you punch yourself in the face. Electrically that's what
's happening on the inverter end of things

 

[TheYeti]

After adding the wifi so growatt could take a look this is the latest response from tech support they've turned on the auto restart setting and asked if we are happy with this solution? ? Also added a picture of the only battery information I can get when it shuts down

 

[Vigo]

That's like me telling the doctor i'm having fainting spells and them saying "yeah but as long as you regain consciousness every time you're still alive right LOL". Yeah thanks doc.

So, continuing on with this diag, do you have grid power wired to the AC input? If not, is this shed 'extension cord close' to a house with grid power, or do you have a 240v generator? The reason i'm asking is because it may be useful to see if the battery does the same thing when you are charging it at 20amps from the ac input rather than the solar controller.

Another question: Have you ever run 20a+ out of the battery to power loads? That would be roughly 1000w+ of load with no solar input to hit 20+amps out of the battery. Reason i'm asking that is because if the battery is having problems at 20+ amps coming from the inverter, it could be an inverter related problem such as excessive AC ripple or some other kind of noise on the DC circuit, but if it does it at 20+ amps in BOTH directions it would have to be battery/bms problem.

I think the answers to those might narrow this down most or all of the way to the source of the problem.