I don't have a Sunsynk, but looked into them before getting my Solis. The datasheet and installation manual I have for that model says 2 MPPT and 1 + 1 strings, which isn't very clear (to me it means just 2 strings). The image in the install manual only shows 4 MC4 connectors - i.e. 2 strings, So might be worth double checking that before you buy.
2 strings or 4?
- Thread starter Niko22
- Start date
I’ll double check.
Definitely 4 strings. 8 MC4 connection ports.
2/2+2
Hi again,
So my installation was finished today except for a battery comms issue. I've ended up with a Pylontech us5000. On the inverter display I'm getting the screen with all the zeros on the battery page. Also when the load is still pulling from the grid although the solar panels are charging the battery (I think). I suspect it may all be linked to the lack of comms.
Should I be using the Cbus port or the RS485?
Should I be using the yellow cable?
I also think my battery charge/discharge settings are all over the place.
If anyone can help me resolve the comms issue I'd be very grateful
Thanks
So my installation was finished today except for a battery comms issue. I've ended up with a Pylontech us5000. On the inverter display I'm getting the screen with all the zeros on the battery page. Also when the load is still pulling from the grid although the solar panels are charging the battery (I think). I suspect it may all be linked to the lack of comms.
Should I be using the Cbus port or the RS485?
Should I be using the yellow cable?
I also think my battery charge/discharge settings are all over the place.
If anyone can help me resolve the comms issue I'd be very grateful
Thanks
Sorry, I've no idea... @houseofancients ?
houseofancients
Solar Wizard
All 0 means no comms..
Your lithium setup is just fine, protocol 0 = pylontech , so inverter wise looks good.
What you should check :
Is the comms cable connected to the BMS port inside the inverter ?
Are you using the proper cable ( pin-out) ?
If you're using a pylontech supplied cable, it should be marked which end goes in the batteries and which in the inverter, sometimes it helps to swap.
if using your own utp cable , make sure the pin-out on both ends is correct.
These videos, while deye ( = sunsynk) , should help
Seems pylontech is specific on connection order :
Your lithium setup is just fine, protocol 0 = pylontech , so inverter wise looks good.
What you should check :
Is the comms cable connected to the BMS port inside the inverter ?
Are you using the proper cable ( pin-out) ?
If you're using a pylontech supplied cable, it should be marked which end goes in the batteries and which in the inverter, sometimes it helps to swap.
if using your own utp cable , make sure the pin-out on both ends is correct.
These videos, while deye ( = sunsynk) , should help
Seems pylontech is specific on connection order :
Last edited:
I'll ask my installer tomorrow. It's a black one. I'm sure he said the yellow one wasn't long enough....
houseofancients
Solar Wizard
So let him check the pin-out.
This is an example universal to all sunsynk/deye/sol-ark BMS ports.
You board layout might look different, but port pin-out will the same
Pin 4 and 5 are the canbus ports on the inverter side.
No clue what they are on the BMS side as I don't use pylontech batteries.
Furthermore, be very much aware that pylontech are 15s and not 16s , so you voltage settings will look different from most here.
Should be set correct ( and will override ) any setting done in the inverter, but make your installer double check, so you don't over charge those nice batteries
The voltages seem high to me. I will check the Pylontech manual. I've made sure the cable is at least in the right port.
Attachments
Good job you mentioned the voltages because my charge voltage is for a 16 cell battery. I've switched the battery off for now and will call the installer tomorrow
Attachments
So it turns out the wrong comms cable was used. My installer came back today and tried the other cable and straight away comms was established.
Overall I'm very happy with my install. I ended up having 14 panels on the east roof and 12 on the west, 2x7 & 2x6. Now that my battery is communicating properly I just need to tinker around with my timers, work modes and SOC limits etc.
The only thing I'm unsure about is the settings for "float", "absorption" and "equilization". These are set at 55.2V, 57.6V and 57.6V respectively. Are these values the default Sunsynk values for a 16 cell battery or has the inverter chosen these values now knowing, via the BMS comms, that it is coupled to a 15 cell 48V battery?
Overall I'm very happy with my install. I ended up having 14 panels on the east roof and 12 on the west, 2x7 & 2x6. Now that my battery is communicating properly I just need to tinker around with my timers, work modes and SOC limits etc.
The only thing I'm unsure about is the settings for "float", "absorption" and "equilization". These are set at 55.2V, 57.6V and 57.6V respectively. Are these values the default Sunsynk values for a 16 cell battery or has the inverter chosen these values now knowing, via the BMS comms, that it is coupled to a 15 cell 48V battery?
houseofancients
Solar Wizard
Don't worry about float and eq.
They are :
1. Not used when using lithium
2. Overridden by the BMS when comms is active.
And yes they are default values, but for lead-acid
For absorption, use the max charge value currently comming from your BMS ( check in lithium status screen)
Should the cable ever fail, it will be your fall back
Thank you very much
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