Derek Ramos

I’ve just bought a sunsynk 8kw inverter and 3 x 5.12kw sunsynk batteries from Ellie’s because they are one of my suppliers. So once I’m all installed and I’ve issued my paperwork for warranty purposes I will let you know if they have extended my warranty to 10years. 

So after lots of research on this forum and a crazy amount of help supplied by the members from the forum I am finally on my way with my install. 
 
equipment used:
1x 8kw sunsynk inverter
3 x 5.12kw sunsynk SSLB1 batteries
16 x Jinko 545watt panels(S&W says18 is to much)
1 x Merson 160amp battery disconnect with 160amp fuses.  

OBO trunking and fittings from o-line, will be using 25mm sunsynk battery cables doubled up to the battery disconnect, 35mm cable from the battery disconnect to the inverter. 90% of my switchgear will be Onesto from MCE. 
 
special thanks to @WannabeSolarSparkyfor providing me with a great amount of information regarding this install. 
 
Because I am only one man doing this install it will take a couple of weeks so I’ll post progression pictures as I go along. I’ll also be able to answer any questions but MOST of all I would like any criticism or advise from all the experts on how or what I could do to better the install. 
 
panels and dc electrics will come in the following 2 weeks or so
 
thanks gentlemen! 

Geewiz and Mecer are similar inverters both of Axpert type (Voltronic power) but branded.
Some rated as 3000VA / 3000W and other 3000VA / 2400W.
Growatt seems to be more expensive.
Choose one which is most cost effective for your use.

Any of the Mecer/RCT/Growatt/Kodak and clones without comms that have the USR settings should work on voltage settings. 

To use PMBS tools is easy, you can download the software (a few battery manufacturers and resellers list it on their websites). You also need a Battery to USB cable. I am not familiar with the Synsynk batteries, so can't help with the exact cable you need. I am sure someone on this forum will know. It is a very handy tool, even if you don't have issues it is very useful.
I tend to agree with you, it is likely a firmware issue that should be solved with an upgrade to the latest available firmware (I have seen this before on a different battery, there a firmware upgrade fixed it). 

Are the batteries communicating with the inverter using CAN or RS485?
If it is then this will override any charge settings you put into the inverter, these settings will be ignored.
As long as you don't exceed 3.65v per cell your battery will be fine and you can expect many years of use out of it.
The only way to achieve wat you want is to turn off the battery / inverter communication and use voltage settings to try and charge to lower voltages, but beware that it is virtually impossible to estimate SOC using voltage settings, so you might think you are charging to 90%SOC while you are actually only hitting 80%SOC.
It only one battery is giving you an alarm I would think that it is an issue with that battery as opposed to the inverter, charging circuit, wires and connections etc.
Can you see what the BMS is reporting using PBMS tools ? This will be the only way to self diagnose wat is happening.
 
 

hope you get that sorted

Hi Joe, 
you are 100% correct, you have to many panels on one string… after getting some professional advice I landed up using 16x 470 watt panels… 8 panels per string just for safety purposes… in future if I don’t find the same panels I can connect all 16 panels on one string by connecting 8 in parallel… but that’s another story.
 
about your setup, if you connected  6 panels on each string it won’t effect your solar production because your panels will still be hitting the same amount of sun time… your inverter will combine both string solar production… even if it did effect your production I would still only put a maximum of 8 for the safety of your inverter. Someone told me that they just make the 150v startup voltage with 4 panels on one mppt so I would suggest going 6 panels per string per mppt. I think you just looking for trouble have 12 panels on 1 mppt. 

I’ve just gone through this whole exercise on what inverter, batteries, panels , geyser timing and so on. I also have a crypto mining rig. 
 
bottom line is that this doesn’t need to be done all at once, I would rather get the right inverter and battery or batteries first and set yourself up for load shedding. You in the meantime can get your electrical in house sorted out for essentials and non essentials and then as you get more funds start adding one panel at a time until you get to the point that you have enough panels. 
 
for me, the sunsynk was a no brainer, most people use them and almost everyone suggested you should use them. There’s obviously a lot of reasons why…
 
if you do this exercise correctly then you only going to do it once, if you get inferior products you might be redoing your whole installation twice. At the end of the day it’s all up to you but just do it right the first time even if it takes you longer to complete rather than wasting money. 
 
eg, my 8kw sunsynk arrived yesterday, super excited but I have nothing else. I haven’t decided on what batteries yet but I was 100% sure of the sunsynk, that’s why I’ve already bought it. 
 

My utility provider can’t even supply me with constant electricity. 😀 jokes… 
 
I’ll look into this, thanks 

Thank you, I’ll be posting another updated picture today. 

Yes there should be 

No it would make no difference.  Both drawings are the same with respect to getting the grid power to the plug where the meter is connected.

Most important is that the voltage is high enough for the BMS to actually balance the cells. Unless you are building your own battery and configuring the balance voltages yourself, stick with the manufacturer values.

Yip this is specifically for lifepo4 chemistry due to the extremely flat charge/discharge curve, as you essentially let the batteries charge at that lower voltage and absorb fully.

While charging, he mentioned that you can charge the battery at 3.4v. this is the video I watched 
 
 

Stick to what the manufacturer recommends for voltages. Current can be lower, but won't make much of a difference once you get below 0.5C. I don't think you can even change the voltages if BMS comms is properly working.

So I watched an interesting video from Andy off grid garage, he stated that you could charge lithium iron phosphate to 80% at 3.4v. 
 
when looking at the specs of my batteries it says the I have 1p16s in each battery. Does this mean that I can multiply 3.4v by 16 and get a total of 54.4v and that would be a safe charging voltage per battery pack? 
 
just trying to understand what he is saying

Lower is normally better but at a 50A standard charge rate and having 3 batteries even 100A is not too high.

Keep charge amps at or below 20amps per battery
Watch some vids that Andy at Off Grid Garage on youtube has done showing some detailed info on this very subject.

And I’m up and running… we’ll sort of😀
having problems with my batteries syncing with the inverter. So I disconnect all of them and only connect one so I can work out wiring and communications problems. Anyway after stressing my nuts off for awhile I did get the one battery communicating correctly, simulated a power cut and everything seems to be working good. Got my earth/neutral  bonding sorted, battery charges from grid correctly. Only running it as a ups for now because I don’t have my panels installed (Next weekends job).
CT coil reading correctly I think, it displays positive values. 
 
one thing that was causing a problem was my prepaid meter, it’s the one you plug in the wall. For some reason it would not communicate with the outside meter. Was showing error 30.. anyway I ran to the front of my property where there is a plug point, connected the meter, it read correctly, ran back to my house and plugged it in, seems to be fine now but I’ll have to monitor that. 
 
Excuse the battery cable laying around at the bottom. Still have to work out the communication. And get a longer CAN cable. 

And I’m up and running… we’ll sort of😀
having problems with my batteries syncing with the inverter. So I disconnect all of them and only connect one so I can work out wiring and communications problems. Anyway after stressing my nuts off for awhile I did get the one battery communicating correctly, simulated a power cut and everything seems to be working good. Got my earth/neutral  bonding sorted, battery charges from grid correctly. Only running it as a ups for now because I don’t have my panels installed (Next weekends job).
CT coil reading correctly I think, it displays positive values. 
 
one thing that was causing a problem was my prepaid meter, it’s the one you plug in the wall. For some reason it would not communicate with the outside meter. Was showing error 30.. anyway I ran to the front of my property where there is a plug point, connected the meter, it read correctly, ran back to my house and plugged it in, seems to be fine now but I’ll have to monitor that. 
 
Excuse the battery cable laying around at the bottom. Still have to work out the communication. And get a longer CAN cable. 

Thank you, I’ll be posting another updated picture today. 

Looking good so far, well done 

Slowly coming together, it’s tough to work at night when my load shedding is at the exact times I can work.