Danielhaynes

Yea I worked out his bad CAN connection basically on week one. I mean all I had to do was read the manual and see straight away something wasn't right. So its basically always been working. I called them out to look at it and he blindly insisted right in front of me that everything was correct. In the meantime I had found the pinouts online and made my own cable, so plugged it in right in front of him and showed him right there as the CAN page lit up with all the correct readings how wrong he was. He then asked me how to make the cable 🤦🏻‍♂️ Anyway it makes sense that maybe if for whatever reason the CAN fails it would revert to inverter settings, even for just a second so im gonna have backup settings on the inverter low at 52.5v across the board and then just see if i get a random alarm again at some point. its so intermittent that i might have to wait a few months. New battery looks great though.. charged to 100% today and is now gradually on its way back down with no issues so far. the way ive cabled them all up is also miles better than the installer so that may also help the intermittent alarm.

fair comment.. so I need to change all three voltages on that page to 52.5? very occasionally with the two batteries and the installers settings both batteries would go into alarm state if they are at 100% late in the afternoon, maybe once very couple of months or so, and turning them off and back on again would clear it. maybe this is was the cause - overvolt protection. but to be honest I thought it didnt actually matter what voltages you set on the inverter as the bsm link would correct it anyway.... either way ill drop mine down to 52.5 and monitor I think

agreed.... what are the correct settings?

Finished installing the new battery today as per my plan. Just need to tidy up with some extra trunking this week etc to hide the new cabling. All went super well, balanced the batteries until all the lights went out and made the new battery the master - all the data connections are working and turning on the master battery turned the other two on in sync as expected. They are talking to the inverter fine and see it upped the max available charge/discharge according from 100A to 150A. now busy charging up from solar. I've set charge to only 75A as thats all my panels would be able to supply anyway and max discharge left at the existing 90A, all well within the cable, fuses and lugs I have used. All the other battery voltage settings are as per the installer though... can someone confirm they are correct as to be frank I don't have much trust in him at all which is why I did this addition myself. (probably doesn't matter as the BMS should override voltage settings anyway right?) The original installer didn't even leave me with a working LiBms link as he just plugged a standard network cable as a can cable and swore to me that he was correct. Following some research I saw its totally wrong and has to have the correct pin outs from Pylontech to Sunsynk. I made my own cable and it immediately worked. God knows how many of his customers he leaves in the same incorrect state as he does installs every single day (its a big company) and said this is how they always do it! I have a background in IT networking/hardware so the data side is easy for me, most other customers just wont know any different im sure.

According to the app since June 2022 ive generated 7900 units. But in the summer half the day im sat with 100% batteries and the house only pulling 500w while im at work so I could have made loads more. I put a heat pump on the pool mid summer just to try and pull the excess I was wasting which worked great, but it wasn't long until my pool was at 36oC (which felt like a bath) and the solar was once again sat idle all afternoon. It really is stupid that you cant just wind your meter back like the UK... We sit with all this loadshedding but people like me would plonk a bunch more panels on their roof and backfeed the moment they allowed that. - At the moment they want to charge a ridiculous amount just for the privilege to back feed and they pay you next to nothing for the units - just isnt worth it for a small system like mine, last time I looked I would actually loose money. Thus i might as well try and use more myself with another battery The three panels on the other roof actually work nicely in the winter when the sun moves round (they said I could put panels on the long roof at the back to really help the winter if I wanted).. that was the thinking behind that. In the summer I have seen the whole lot hit a peak of 6000W which isnt far off the max, so at least roof direction seems ideal.

Thanks. Yea chimney isnt ideal but actually not as bad as it looks from that photo tbh. We went with that location as the run to the basement garage where the inverter is was already pretty hard work and we couldn't fit all 14 on the back roof as solar geyser takes up area. but I could easily add another string of 10-11 panels on there later If I wanted. Unless they change the stupid rules on back feed and make it worth our while I cant see me ever doing it though as I dont use enough power atm to justify it.

This is the solar install on it just FYI - I have loads of space to add some more panels if I wanted (14 atm), but thats pointless for us without more storage. At least with the inverter I have room to grow if I ever needed.

Oh yea I get that but there is only two of us in this place and everything in it is super efficient and new - dont think ive ever seen us temporarily peak much more than 6000w when we are running almost everything we have so not getting close to drawing the 90A max setting on the inverter atm. The only reason we have this particular inverter is when i bought the house it already had a 3 phase supply (which i dont need), and COCT insisted on the 3 phase inverter. I'm just after a bit more storage as we both work all day and any sunny day our batteries are fully charged by mid day, three batteries on a normal night gets me basically through the entire night off grid so should pay itself eventually (guessing 6-7yrs).

Ok noted - Ill change the fuse to two pole then. Something like this (they do 125a or 160a fuse version, assume 125A still correct for mine): https://www.takealot.com/u2d-solar-dc-battery-disconnect-box-with-fuse-125a-2-pole-white-/PLID93228702 and do both positive and negative. Keeping the 90amp maximum discharge from the inverter. and up the cable from busbar to inverter. Cables from batteries to busbar will be the official pylontec 2m cables I already have and ill leave them all the same length.

Thanks guys, really appreciate the help. I did some more research yesterday and came to the same conclusion, I didnt ever like the two cables sharing the same terminal in the first place which was the main reason for this post. So I think two busbar boxes and while im there add a disconnect fuse which I don't currently have at all. the alternative is buying the pylontech connectors and making longer interconnect cables between batteries but the busbar boxes will be easier and neater imo. photo attached of what I currently have and annotated with the changes. I dont need more current, extra battery is just to increase storage through the night and give a bit more headroom for occasional 4hr loadshedding blocks etc. plus I assume overall battery health will be improved sharing the load over three instead of two in general. the inverter is set as max discharge of 90A which has been perfectly fine for us (generally house never really goes over 2000w in loadshedding, draws about 900w in the evening when we home watching tv etc and constant 400-500w during the night). 125amp disconnect box and 25mm battery cable all seems correct right?

thanks... yea it wont obviously be as neat as stacking them with the short interlink cables but its effectively the same thing right? and easier to mount the batteries on the wall flat for me as it takes up less depth.

each battery has 2m cables that go to the same +/- terminals in the inverter. So yes im being stupid... So what im asking then is if its ok to just mount a third battery on the wall next to it and do exactly the same, i.e have three cables on those terminals (I actually already have a spare set of 2m pylontech battery to inverter cables), one pair to each battery rather than stacking them and using the interlink cables? Link the new battery to the group with a data cable and it will then see 300ah instead of 200ah?

Hi Guys. Quick question. I have a Sunsynk 12kw 3phase inverter and 6.3kw solar array with two UP5000 batteries that was installed 18months ago. Everything has been working fine but im now looking to add a third UP5000 battery to the system. My batteries are generally fully charged by 1-2pm and I use most of my power at night. My question is though that the original installer wired the batteries in series. i.e both batteries are mounted on the wall side by side below the inverter and both have cables going from the battery to the invertor but not to each other, then there is a data link cable between them only. The inverter reads the bms fine and sees 200ah. this is not usually how I see these wired though. should they have been in parallel? Im guessing he maybe did this as the link cables that come with them are super short and designed for them to be stacked on top of each other, rather than wall mounted side by side like he did. If I add a third battery now should I change this or is it ok to just get another set of battery cables and put a third one on as serial, or should now chain together in parallel? presumably you can get longer link cables if I need to? noob question i know, but just want to double check before doing anything.

yes same for me also. no spikes since 2nd sept, three days of clean graphs. so I think they have fixed it.

Im sure solar assistant is much better but tbh sunsynk logger gives me what i need 90% of the time. Not really inclined to spending money on slightly more accurate information. At least on my install atm. Might look into it in more detail in the future though, especially if this sort of thing happens more often.