Growatt inverter shuts off after 20 min when connected to PV

[AHUSAIN]

Yesterday I found that the power cuts off to the inverter even when there is no charging going on. I disconnected the panels to just run the load off the remaining charge in the batteries. This was a little after noon. It was extremely hot. The power cut out after a few minutes. I tried again later in the day when it was cooler and it worked perfectly with no power interruption.

I have noticed this is all usually happening at peak heat times. I also noticed when it happens the 120-240 transformer (my load) is extremely hot. At cooler times the transformer stays cool even if it runs for a long time. Not sure if these are reasons but it might be a clue.

 

[AHUSAIN]

In the interests of getting a quick solution since I'm about to enter the desert today I was thinking I can just get some replacement AGM or lead acid batteries today and hopefully that should give me a temporary fix.

I don't have experience with BMS's and I had limited time to set all of this up so I couldn't learn it in time. It seems my lack of BMS is contributing to the power issue. I did purchase the Valence BMS but didn't realize it was the high voltage version requiring a minimum of 100v input.

So I'm just wondering can I use AGM's without a BMS and expect better results? The Growatt has several settings for battery management and protection (low voltage, high voltage, etc). Also the manual only suggests a BMS for lithium batteries. Any advice on AGM without BMS would be appreciated. Thank you.

 

[HarryN]

I will look through the manual tonight.

In general, good quality AGM batteries can deal with the heat better than Li.

A BMS is only required in Li type batteries due to their nature. A BMS is really never needed in AGM.

Try to get at least 4 each batteries. Ideally something like size 31s if you can fit them in there.

The ideal battery is a Lifeline GPL-31 XT or similar, but I am not sure what will fit.

If you can add a fan to help vent heat out of that compartment that will also help.

The run time for 4 of those AGMs will be roughly 2 - 3 hrs, similar to what the existing LiFe ones would supply if brand new.

Get a marine style AGM - not a deep cycle or starter battery.