Sunsynk 3.6k LiFeP04 or not?

[Fingers]

Sunsynk inverter Sun-3.6k-SG05LP1-EU
Does it have LiFeP04 (Li-iron) option in the "Lithium" battery selection?
I don't want to use open loop if it's avoidable.
If so, does it communicate with a Jikong BMS?

I did ask Sunsynk but all they said was "yes LiFeP04 is Li-Iron". The manuals state Li-Ion or Lithium, and no mention of LiFeP04 or Li-Iron.
It's very annoying, as when they do answer emails, they are as evasive as a second hand car salesman.

Thanks for your help.

 

[Samsonite801]

Did you happen to review the manual for it yet?

https://www.deyeinverter.com/deyeinverter/2022/06/30/%E3%80%90b%E3%80%91%E4%BD%BF%E7%94%A8%E8%AF%B4%E6%98%8E%E4%B9%A6-%E5%82%A8%E8%83%BD%E5%8D%95%E7%9B%B8-sun-(3.6-8)k-sg05lp1-eu-%E5%BE%B7%E4%B8%9A%E8%8B%B1%E6%96%87-%E5%B0%81%E9%9D%A2%E5%BD%A9%E5%8D%B0-%E5%B0%81%E9%9D%A2%E5%B0%81%E5%BA%95157g-%E5%86%85%E9%A1%B570g%E9%93%9C%E7%89%88%E7%BA%B8-142.5x210mm-ver2.2-%E6%96%B0%E6%9C%BA%E5%A3%B3.pdf

Page 30 (Page 28 in document):




These are most likely intended for LiFePO4 (same as LFP), which is Lithium Iron Phosphate. It is not near as common to use a Li-Ion or other chemistry in home solar implementations.

But also, whether it supports Li-Ion vs LiFePO4, probably has more to do with what the BMSs are, since that setting for Lithium battery in the Deye settings is probably assuming the BMS comms connection implementation (so the inverter can get SoC from BMS). So this encompasses Deye supported lithium battery modules with comms link enabled (reading SoC % off BMS to control charging).

So the question might be, does the Deye all-in-one support good comms with the Jikong BMS?


Besides that, if you won't be using the default lithium selection (which probably requires the compatible BMS comms link), you would most likely just be using the 'Use Batt V' (without comms link) for your LFP battery, and just set your custom charge profile voltage parameters manually anyways.


Page 31 (Page 29 in document):



Note, that you never want Equalization with LFP, so you would set the voltages for Absorption and Equalization to the same which effectively disables Equalization. Not sure if setting the Equalization Days to 0 might also disable, but just to be safe, set volts the same.

Then you can start out with Will Prowse's sticky on the basic settings for charger stages and inverter cutoff voltages:

Recommended Charge Profile for DIY LiFePO4 Batteries *Sticky Post*

12V 4S LiFePO4 Battery w/ BMS: Absorption: 14.5V Float: 13.6V Inverter Cut-off: 10.7V-12V (depending on size of load and voltage drop etc) 24V 8S LiFePO4 Battery w/ BMS Absorption: 29V Float: 27.2V Inverter Cut-off: 21.4V-24V 48V 16S LiFePO4 Battery w/ BMS Absorption: 58V Float: 54.4V...

diysolarforum.com

So I guess you need to figure out if you can get BMS communication to work or not before deciding which direction to take.

 

[Fingers]

Thank you for the information.
The Deye manual, the layout and wording is different to the Sunsynk manual so it will be a help.

 

[Fingers]

The man from Sunsynk he say no!
li-ion not li-iron. And yet at least one of their batteries is LFP (li-iron).

 

[Samsonite801]

The man from Sunsynk he say no!
li-ion not li-iron. And yet at least one of their batteries is LFP (li-iron).

But does that Batt Mode 'Lithium' setting assume a BMS comms connection? If so, and if you won't be establishing a BMS comms enabled connection, then you wouldn't use that setting anyways? Would require to use the Batt Mode 'Batt V' setting, which means you set your own custom charge stage voltages anyways? Perhaps some clarity from the Support guy on that could further clear things up?

 

[Fingers]

Further communications with Sunsynk, all of the batteries are LiFeP04 although on their website and on just about every website that sells Sunsynk products they state li-ion, and the pdf files state LFP. Sunsynk claims spelling mistakes
I'm guessing this is down to copy - pasting and not updating, a progression from li-ion to li-iron without the fanfare. Well how would they get rid of the old stock of li-ion if everyone knew LFP was available.
Personally if I were Sunsynk I would have that fanfare and blase LiFeP04 stickers over the front of the inverters and batteries.