Hello, my name is Julian, I am completely new to this forum, and I live in Brazil. I hope it is not a problem that a foreigner is using your South African forum, but I didn’t know where else to go. Where I live, not many people have solar yet, and it is difficult to find knowledgeable people who might have answers for people like me, who are not very experienced in dealing with solar and solar equipment.

Over the last three or four years, I have been teaching myself the basics on YouTube and have had a 3,3 Kw system running for the last two years with a Growatt hybrid, inverter, and eight lead acid batteries. until now, I have not had any problems, and have enjoyed the benefits of having a lower energy bill, and being the only person in the street with energy when we have blackouts, which are quite regular.

The problems started this week when I decided to change my eight lead acid batteries for one LiFePO4 battery. My inverter is a Growatt SPF 3500 ES, and my new battery is a Narada 48 NPFC 100.

What ever I do, I can’t get the system up and running again. I’ve tried with, and without a BMS, followed all the instructions in both manuals, but I keep getting alarms when I set my battery as lithium. Alarms 4 (low battery voltage) and 20 (BMS error).

When I manually set the parameters for the battery and don’t choose lithium and don’t use the BMS the battery voltage is higher like it should be, and the inverter works for a about 30 seconds before shutting down. In these 30 seconds the solar panels, try to send energy to the battery, but it looks like they keep being disconnected. The voltage is OK, but every time they build up some wattage, it’s like they are being turned off and go back to zero. in this case, I also get an error code 19, which is battery disconnected when it definitely isn’t disconnected!
I really don’t know what to do anymore, my system was working perfectly before, and I thought it would be better and easier using a lithium battery with BMS. Hopefully I’m just making some kind of stupid beginners mistake, and I really hope someone on this site with more knowledge than me can maybe point me in the right direction, and tell me what I might be doing wrong.

By the way, I am using a normal ethernet cable, like the normal ones used for Internet modems for my BMS communications. That is Ok isn’t it?

Any help or tips to get me a step closer to get the system up and running again would be really appreciated. Thank you in advance.

 

 

 

 

Edited November 9, 20232 yr by Julian K

10 hours ago, Julian K said:

What ever I do, I can’t get the system up and running again. I’ve tried with, and without a BMS, followed all the instructions in both manuals, but I keep getting alarms when I set my battery as lithium. Alarms 4 (low battery voltage) and 20 (BMS error).

I have 2 of those narada batteries and have never figured out how to use them with my growatt 5000es ended up simply using the voltage settings method.
Works great as long as you set all the correct voltages in the USE settings.

Maybe some other forum members had better luck with narada batteries.

Good luck

12 hours ago, Julian K said:

 

By the way, I am using a normal ethernet cable, like the normal ones used for Internet modems for my BMS communications. That is Ok isn’t it?

 

 

 

 

 

Hello Julian. You need to get the right cable to connect inverter to batteries, standard ethernet is not ok. You also need to configure the dip switches on the batteries if you have more than one.

Check the user manual of batteries and inverter.

Edited November 10, 20232 yr by Mauritius B

Hello @Julian K

Welcome attached manual for your battery the comms protocols are explained, comms cable pin outs and the dip switch settings. If you battle with bms comms i suggest what @WannabeSolarSparkysaid above get it going for now on voltage settings under "use" but try and get the bms comms to inverter sorted out as it is best for the long run. I would suggest you disconnect the battery first, then reset the battery and before connecting do a pre-charge when connecting the battery to the inverter. You can use a car headlamp around 24 ohms or a 30 ohm 25w resistor. Connect the negative cable from battery to inverter and tighten. Then put the resistor or headlamp between the pos batt cable and touch the other end to the pos on the inverter and hold it there for 10 seconds, then immediately after removing connect the pos batt lead to inverter and there should be no arc. Good luck.

 

 

OM-Narada-NPFC-Series-Li-Ion-0423-V8.pdf

3 hours ago, WannabeSolarSparky said:

I have 2 of those narada batteries and have never figured out how to use them with my growatt 5000es ended up simply using the voltage settings method.
Works great as long as you set all the correct voltages in the USE settings.

Maybe some other forum members had better luck with narada batteries.

Good luck

Thank you so much for your quick reply. Maybe I should try this for now and try and get try to the BMS sorted out somehow later.

Do you happen to have the voltage settings for charging, float, back to grid etc? 

1 hour ago, Mauritius B said:

Hello Julian. You need to get the right cable to connect inverter to batteries, standard ethernet is not ok. You also need to configure the dip switches on the batteries if you have more than one.

Check the user manual of batteries and inverter.

Hello Mauritius and thank you for replying. 
The dip switches on the battery are conform what the manual said.

I have so many cables similar to these lying around. Do you happen to know how I can see if one is suitable or not? The connection is exactly the same as I use for my Internet modem.