CaptRic

Mr. T, I have looked at your User Manual for your particular Growatt.. I have attached what you may already have seen, but not reconize why your Fault code 20, which simply means BMS and Growatt are not talking - Becasue if you look at the Growatt, One you have to use the BMS port, Two, you see that Pin 1 and Pin 2 of the Growatt is why when cabled with the network cat5 cable the other end to the Can of the Battery is not on the same Pin, you need to take the wires from the Growatt end rj45 plug which should be Pin 1 verify colors of the pairs and Pin 2 for the Growatt end. A normal cat5 cable generally is Pin1 White with orange strip and PIn 2 solid Orange.. and Pin 4 on the battery rj45 plug will be Blue and Pin 5 is White with Blue Stripe.. Please look at your cable ends colors close and verify which needs to be changed.. I believe you need Pin 1 of Growatt bms end to connect to Pin 5 white/blue stripe to the Can Battery plug end,and Pin 2 of Growatt end to Pin 4 Blue of the Can Battery end. See my picture attached as pdf showing clear Pins of the cable ends. Just cut a short cat5 Spare cable with ends say cut 10 inchs for the battery side end, so you can remember which end is going to the battery, always and not be mislable because tht end has to be in the battery side. and the longer of the 6 foot cable end goes to the growatt.. the other wires have no value for the Growatt as it only uses Pin 1 and Pin 2 as seen in the Manual. See Attached PDF file with pictures, etc. Also remember in the picture I sent of pins locationis back or bottom, fliped over, where Growatt looking in from top, pin 1 2 and 7 8 look reversed , No its just the back side front side the Pin positions same, u just have keep which side your looking at. the colors of the wires will help keep pin positon always correct.. SPF3000 HVM Growatt Cable Pins BMS Bat Pins Pic.pdf

Mr T, As a few others are mentioning. A. your Fault 20 is because the Growatt is not able to communicate with the BMS.. B. Its very possible that your Network cable for the Growatt end needs to swich wire with the BMS end pin pairs.. example but not specific for you. just example is if the BMS of your network Cat5 cable that connects to your PYLON Tech battery is usine #4 pin Blue #5 pin White/Blue Stripe which is called a twisted pair, the Growatt #1 pin White/Orange Strip needs to be connected to #5 pin position of the BMS end, and Pin #2 of Growatt to Pin #4 Blue wire of BMS end. But first Confirm your Growatt BMS and RS485 ports on the Growatt if pin#1 pin#2 have voltage with ohm meter, should read about +3.32volts, and or Pin #7 and #8 of the Growatt as well. Reason I mention that is my Growatt uses BMS port only, is RS485 only and uses Pin#1 & Pin#2 only +3.32 volts. Your Growatt may be different. Also please check out SiliconKid he had the same issues and has a nice explaination and information that may help.. Here is the link: You will have success.. Recommend if your handy, take a spare Cat5 Network cable, cut off a 2 foot piece from the rj45 good end, expose the wires, by stripping back the outer insulation by at least 3 inche, caution not to bare any of the pairs of wires internally . now strip 4 wire ends, #1 & 2 pins which should be twisted pair Orange and White orange stripe, and Brown#8 and White Strip Brown pair.. bare the ends, make sure not to have the exposed ends to touch each other while plugged in. Stagger the wire lengths of those that way they can not accidentally touch each other. Now plug into your Growatt ports BMS /rs485 and measure the voltage. DC volts.. ignore if your getting milli-volts. has to be +3.32 or -3,32 Volts DC make sure your multimeter is set for DC volt reading. now you will find out what port rj45 on the growatt and what pins are providing power for the BMS battery. I don't know for your particular BMS Board in your Battery what Pin # it uses.. mine is #4 and #5. yours could be different and you need to know that for the correct cat5 cable connection to work with your Growatt. But check out SiliconKid and what he has, which is similar for You. Enjoy Best Regards, Ric ps. Attached Pic of Growatt Port and Pin layout RS485 SW Picture BMS.pdf

Mr T, which Growatt Inverter specifically you have.. I may be of some help, if your using PYRON Tech battery and if your using L1 05 menu, are you seeing on display screen of the Growatt to right side of the Battery Icon a very tiny icon that says L1 symbol ?. One reason its possible if your setting up as Lithium Battery , but the Growatt in not configured correctly with the particular PYLON battery. Protocol, Let me know if I an help. but need more specifics as to Model of Growatt, and Which PYLON Tech Battery Regards, Ric

Hi SiliconKid, First want to directly thank you for giving me some light about the Growatt issue.. however there are some things that vary depends on your particular Growatt. You referenced the Menu #5 setting L1 L02 for PYLON Tech battery, and Pin sw settings for the Growatt.. etc. I am glad it all worked for you. However so no other like myself don't directly try to use your configuration is they are using a Different Growatt Controller. In my case, I using SPF6000T-DVM off grid Controller Charger Inverter. I can't for sure speak for all Growatts, just my series which have a range SPF4000-12000T. But on top of that the Growatt i am using 6000T and up to 12000T use only the BMS Port rj45 for BMS communications with Lithium batteries, RS485 protocol Only. And Pin 1 and 2 are souce nothing else. In my case I have Seplos BMS control boards running my 3 - LiFeP04 150ah batteries. using Menu #5 L1 51 L01 setting . So for those who like you and I trying to get their Growatt to communicate with their Lithium batteries.. They need to know who's BMS board and what are the Pins from the Master Battery is using more than one, what the required SW pins are to ON for the Boards and what the Master BMS Board Cat5 Network cable that is being connected to the Growatt what Pins of the rj45 cable end need pins to connect to the Growatt end of the cable for Pin 1 & 2 and or Pin 7 & 8. Thank Again for this help you shared as it will and has shed light on the issue with Growatt and BMS Battery communications. Best Regards, Captric Growatt SPF6000T BMS RS485 SW Picture.pdf

New Here want to share some important information I learned after weeks months to get answers for Communications Between Growatt and BMS Lithium LifePo4 type batteries. Specifically I am using Growatt SPF6000T-DVM OFF Grid transformer type Controller/Charger/Inverter Split Phase The series range 6000T - 12000T models use the BMS Port Only of the Growatt to communicate and is Strictly "RS485" communications. Also note that only RJ45 Port Pin numbers one (1) and pin (2)two are the supply source for communications to your BMS Battery board. Thus, you need to find out from your battery mfg, what BMS board you are using, meaning. you need to know what Pin number of the rj45 port and which port to use from the Master Battery BMS, meaning RS485 or CanBus port of the BMS The issue is Growatt depending which model and which Battery BMS you have to get it to work and communicate. So you will not find a lot of support from Growatt or in my case the specific manual to help you figure out the correct settings for Menu #5 in the Growatt, Like L1 is a given, then you need to know after entering, then enter again in L1 select L01 which is basic for Growatt - or L02/L04 is for PYLON Tech Battery and there are more to choose, but normally for those Battery BMS control boards you need to find what Pins are used. So you can splice into the Cat5 network cable used and change pin 1 and pin 2 that goes to the Growatt to connect to the proper pin of your BMS end of the cable to the BMS Battery. Please before making any changes, please verify with your Battery mfg the information. Some will be Plug and Play for you.. But if your like myself took weeks to find the anwers and make the pin changes now with success my Growatt SPF6000T -DVM off grid is communicating wiht my BMS Board. I have to give all the success to my Batteries BMS to Communicate with my Growatt to Tech Link and SEPLOS who makes and supplies the Boards for my LiFeP04 Lithium batteries. I have 3 batteries 48v- 150ah LiFeP04 Lithium batteries, BMS boards from Seplos Company RS485 configured.. They provide both rs485 BMS and CanBus BMS boards. Again you must make sure who and what type BMS boards you are using in your batteries is your like me, Not able to get your Growatt to communicate with your Batteries BMS.. It can be done. If I can be of help let me know.. I want to make a special thanks here on this forum to SiliconeKid who helped turn on light bulbs in the right direction for the similar issue he had and I have. But again he was using PYLON Teck batteries but could not get them to communicate with his Growatt, different model than mine but same issue as I had. Thanks SiliconeKid for the light bulb vision. CaptRic RS485 SW Picture BMS.pdf