I have a setup for a client which has 2x Growatt SPF 3000TL LVM connected together, communicating in split phase. These are connected to a single Narada 48NPFC100 battery. I am aware this is a non-standard setup and has little battery power for the amount of incoming solar, but this was the request of the client.
The issue I am facing is that the client is attempting to continuously run high volume loads at night (several fridges) and they are consistently (every 3-4 days) running the batteries to the low voltage cutoff (currently set at 46V). This would typically be okay as the customer is aware of the downfalls of running the batteries very low, but a combination of factors are causing this to be very irritating to deal with. When the Growatts are led into a low voltage cut-off, they appear to enter into a standby mode, or completely turn off until the voltage returns to a higher value. The issue with this is that the Narada 48NPFC100 that I have struggles to compensate for the startup current of the inverters and will go into an alarm state unless done correctly. The current surge alarm is extremely sensitive on this model compared to other lithium batteries I have seen and it CANNOT start the inverter up in normal operation. I have other models of Narada batteries on other inverters (some with an even larger capacity) which do not have issues with this. It is a somewhat involved process:
I have made a switch that goes through a 25ohm, 50W resistor as a "startup switch" (picture attached). In order to start the inverters, they must first be charged up by the resistor then switched on normally. This works 90% of the time but occasionally does not work. I am not on this site consistently and this results in a lot of calls from the site trying to get assistance restarting the system. This happens frequently enough that it is a problem. I am currently talking to both Growatt support and Narada support to attempt to ease this process but I am essentially looking for one of two solutions:
1. The Growatts do not enter a complete sleep state when they hit low voltage cutoff. This would allow them to enter normal operation once power arrives from the panels again at dawn. This are complete off-grid inverters so there is not the option of switching to grid power to sustain the final hour or so until dawn.
2. The Narada battery doesn't enter an alarm state when starting up the inverters. This means the employees can simply power cycle the battery each morning as soon as the sun is up and there is no issue.
I am installing a SolarAssistant on the system today so that the employees can better manage the usage and be conscious of when the batteries are about to cut out. This will hopefully mean that this occurs less. If anybody has any experience with issues of this I would love some input!
Cheers!
The issue I am facing is that the client is attempting to continuously run high volume loads at night (several fridges) and they are consistently (every 3-4 days) running the batteries to the low voltage cutoff (currently set at 46V). This would typically be okay as the customer is aware of the downfalls of running the batteries very low, but a combination of factors are causing this to be very irritating to deal with. When the Growatts are led into a low voltage cut-off, they appear to enter into a standby mode, or completely turn off until the voltage returns to a higher value. The issue with this is that the Narada 48NPFC100 that I have struggles to compensate for the startup current of the inverters and will go into an alarm state unless done correctly. The current surge alarm is extremely sensitive on this model compared to other lithium batteries I have seen and it CANNOT start the inverter up in normal operation. I have other models of Narada batteries on other inverters (some with an even larger capacity) which do not have issues with this. It is a somewhat involved process:
I have made a switch that goes through a 25ohm, 50W resistor as a "startup switch" (picture attached). In order to start the inverters, they must first be charged up by the resistor then switched on normally. This works 90% of the time but occasionally does not work. I am not on this site consistently and this results in a lot of calls from the site trying to get assistance restarting the system. This happens frequently enough that it is a problem. I am currently talking to both Growatt support and Narada support to attempt to ease this process but I am essentially looking for one of two solutions:
1. The Growatts do not enter a complete sleep state when they hit low voltage cutoff. This would allow them to enter normal operation once power arrives from the panels again at dawn. This are complete off-grid inverters so there is not the option of switching to grid power to sustain the final hour or so until dawn.
2. The Narada battery doesn't enter an alarm state when starting up the inverters. This means the employees can simply power cycle the battery each morning as soon as the sun is up and there is no issue.
I am installing a SolarAssistant on the system today so that the employees can better manage the usage and be conscious of when the batteries are about to cut out. This will hopefully mean that this occurs less. If anybody has any experience with issues of this I would love some input!
Cheers!
