FixAMess

The SA public are being hoodwinked by installers. The installers push a brand of inverter that suits them, not necessarily what's in the best interest of their clients. The sunsync vs luxpower point above confirms this. It used to be Victron or nothing, now it's sunsync! Who really needs a bidirectional inverter. Most installs actually limit the feed to grid anyway...

Interesting.. I have 4 pylontechs, all of different ages and I don't see such big differences...I need to check! Maybe they are different.

I'm surprised that in 4 months usage beyween the old and new, the batteries are so different. What are they like when fully charged and balanced? Try making no 1,4 batteries 2,3 in the parallel chain. It's your first and last battery thst are taking more load. Swap 2 ,3 to 1, 4. Are you able to check individual cell voltages?

The Ah is a setting on the BMS, not really a firmware upgrade? What firmware was upgraded, the inverter?

This is why I tested the batteries I import before making promises as to their capacity! A 100Ah battery, tested to depletion, had a capacity of 107Ah, but it's sold as a 100Ah battery. You probably find those batteries came from a different batch and the "new" batch is not at 120Ah! We just assume that a battery sold as 120Ah is in fact capable of delivering 120Ah, we take the sticker as being gospel, but do we actually test? Unfortunately, there's no testing body that verifies the data on the battery stickers is correct.

There is a toolset that allows one to interrogate the BMS, pretty much the Pylontech batteryview equivalent. I will find the app and upload a link to it if anybody wants it..

I cant provide info to solve your problem but do you perhaps know what the BMS make is?

To prevent the constant charge, discharge cycle, set your batteries to discharge to e.g. 5% when on-grid? This is good for the battery...

Interesting! If it does not have a CT coil and it can feed non essentials, how does it stop feedback?

The luxpowers SNA5KW are off-grid inverters, not bidirectional, so if you split your db then you should not be feeding back to the grid. Does your inverter come with a CT COIL? If it has a CT coil it's bidirectional (can feed grid) If however you just took your inverter output and put it onto the input of the db then you could be feeding back and tripping the conlog...I've seen this approach in a few installs. If you split your db, the conlog must sit on the nonessential side and the rest of plugs, lights, etc on the essential side, no feedback into the grid. If you're In CT, there was a thread mentioning that all inverters must be grid tied (bidirectional) going forward. If my understanding is wrong then please correct me..

This! Those panels Voc are probably in the region of 50V, so 12 takes you to 600V split across 2 strings (???), so 300V. So from a voltage perspective you may still have room. What is the max Voltage specified by sunsync, is it not 500V per string? Don't forget to take temp into account in your calculation, but remember your inverter mppt can only provide max 3200W per mppt / string. Remember, the sunsync can invert 5kW ( DC to A/C ) , but still allow DC charging in addition to that which probably accounts for the max of 6500W.

Cycles?

Yes, but if you are using std Pylontech cables you should still double up on the cables...

So you bought them at 120Ah and after 2 yrs of use they're depleted by approximately 4% per year... So after 10 yrs of use (assumption, assumption before I get crucified) they'd be depleted by 40% , which aligns with most battery warranties, 60% life after 10 yrs.. One wonders if the spread of available Ah after 2,5 yrs of work is similar in non-2nd-life batteries, 98Ah vs 114Ah? @igg, do you have any idea why they depleted so differently? Were they used in the same battery? EDIT: I see they only did 480 cycles over the 2.5 yrs, then the depletion is not what I would expect! Question; are 2nd life batteries, based on the above figures, and if they really all started at 120Ah, a good buy?

I import batteries with PACE BMS. On a new 10kWh battery we found the BMS to be faulty. A quick call to my supplier and a new BMS was immediately posted. I received and fitted the BMS a day later. No issues with warranty, no arguing etc. One cannot just "wipe" the BMS, they are password protected so your electrician would need the software and password to change BMS logs etc. I doubt if he has this. If the poster likes he can contact me and I'll see if I can source him a new BMS at his cost.

You should parallel the battery-to- inverter cables every 5 (37A dischage per battery x 5 = 185A) batteries if you are using std pylontech cables. This gives you 185A/2 per cable, within reccomended std cable spec.

How about a tech comparison and actual user experience view? I agree we need to get over the sunsync hype, there are many cheaper, good quality options out there that provide what most households want from an inverter.

This is interesting! So e.g., a "light" can be put into the non-essential side to show that there is power. Is this the correct interpretation?

Mmmm...one wonders just what the component specs are, are they designed for 18A,22A or 26A? Maybe they are using different components over time, but if they upgrade the 18A hardware to 26A firmware how does that affect the longevity of the inverter?

My understanding is that from the inverters point of view, the 1 mppt sees 1 input ( sum of 2 parallel strings) it cannot differentiate between the 2 strings, so if the strings are different V, I, (specs) they may not be optimal. This is why they should be the same, but it's not necessarily a requirement that they be identical. Even the solar radiance (face different directions) on them may differ, so one would never expect the 2 string output to be identical. I suppose the best way to describe the mppt would be that it provides a best fit voltage on the parallel string,resulting in a non-optimal result across each string individually. Is this correct?

What BMS does the Greenrich battery use?

Just a thought - you will need to maintain/paint your flat roof waterproofing layer every 3 years if you have an existing warranty on the waterproofing.. Take that into account when considering the layout.

please provide the inverter specs, then decent feedback can be given.

@TaliaB how would a laymen check if his system has been installed correctly re E-N bonding when in Island mode?

If this was done correctly, you MUST be connected to the grid. Check your inverter screen where it shows power coming in/ out etc.