RikH

Or when you want it less complicated you can give Hubitat a try. Very nice hub!

Not sure. Since @Wetkitassumes one should earth the negative side of the panels. I don't, never. But I do earth the panels framework and mounting rails etc. So if you don't earth the - PV the batteries are also not earthed via the mppt. Just my thoughts.
Nice topic, thanks for bringing it up @Sammyigt.

Loadshedding.

Who would want to deplete their batteries when Eskom may start shedding at short notice?

OK... some may have a way of calculating and evaluating that risk, but I like to have full batteries at about 16:30 (they usually are full much later) and then live a low consumption life until the sun comes up the next morning. That way I am insulated against load shedding.

In Australia they seek to pay as little as possible for grid usage. Here we seek to mitigate against a loss of grid power for several hours.

Ok, so it is the same as in the Netherlands. When we push back more then we use we get a lower rate and also a tax cut so last year I have let a heater run in the garden in december to get my own usage up for that reason. This is how it works when government is interfering...
Another thing, what is the value of the main fuse in your house, 25A? That is my situation and I simply push back 22A with my inverter. Nobody knows what my peak push back current is so why should you make it that expensive and complicated for yourself?

Jij bent niet bang!

Hold your horses, sir! There are some forumites who will be mighty upset when Victron is mentioned in the same sentence as Infinisolar 🙂
But it does explain why it handles spikes like this (me doing some old-school arc welding) without any apparent problems...

Well it has been a week of slow progress but finally the beast is back online. We have Gotten so intimate that I had to name it! Stima it is, 320P 14S 18650 pack with an average Individual cell capacity of just over 2000mAh.
i am done with this battery and will be turning my attention to the other inverter.

Thanks for all the advice guys, version 2 is done, tested and working as it should just need to wire it in, was a pretty tight fit in the box 🙃
 

Haha, did I proof-read my post? Yes. Did I notice the mistake? Yes. Did I expect someone else to notice it? Yes. Did I fix it... no, of course not, I was only half-way through the coffee recharge 🙂
 

Here is my King installation. 
 
not complete!. I need to wait for payday and get battery fuses and more panels
 

@RikH thanks, the build has definitely been a great deal of fun. I look back at what was a battery to extend the UPS on the computer, then after watch a zillion youtube videos then thinking to myself I will build just a small 24V system to keep the gate and alarm system powered... well I am now at a 48V system and asking myself if I shouldn't just build a battery shed to fit a small 100kWh battery, cover the entire roof in solar panels...... just a few mods that the wife will not notice!

Hi Wozza, welcome to the forum!
First of all you're measuring the battery capacity with the inverter. This is only a guestimate because all the inverter knows is the battery voltage. When you connect a load you will see a voltage sag and the inverter thinks the capacity drops that fast as well but it doesn't of course. If you want a good measurement of the SoC (State of Charge) I recommend to connect a Victron BMV to the battery.
Now you know what the SoC is but the inverter still does not. By adding ICC to the system the SoC can be forwarded to the inverter as well so it (or ICC) makes better decisions.

More on the top DB to follow, thanks for the input, and I will action recommendations.
Now based on the earlier advice, note the additional DB board top right for the DC bits.. I was not planning on doing that, so thanks muchly, would have been pissed if I had to do that after the fact. 
Question though regarding the conduit/single db CoC rule.. My trunking, which is split in the middle is fine right, I wont pick up crap from that.  ? I did plan to split AC and DC within the channels, hence the reason for buying the double trunking, but did not know about the DB distribution. 

Also, the box I have between the two inverters, will be my DC cable joining box,  essentially utilizing studs to terminate cable points. In my view far better then trying to double crimp 35mm wire. Will of course have a cover over it, with some Volt meters for the sake of nerdiness...
So route is to go from the keto disconnect to the junction box, and then out to each inverter. Also circuit 1 of the Keto, will have a 40A for panels, and 2x120A from batteries.. all squishy.. ?
Forgive the gazillion questions, but that's what happens when you let the IT nerds loose with this sort of thing
 

Not sure about the question ether.  RikH and I have the same inverters, and here's my take on it...
The two MPPTs on the inverter are rated at 5kW & 900V each for a total of 10kW.  I have two 4kW series strings (about 500V) so I presume they are fine.  The inverter itself can deliver 5kW at 220V and another 5kW at 48V, thereby fully utilising the 10kW of PV input.  I've heard that it's OK to exceed the maximum PV wattage rating as long as you remain within the maximum voltage limit, but I am not that guy.
In grid-tied mode it can blend utility power if the load exceeds 5kW, but in off-grid mode the 5kW load load cannot be exceeded (as I learnt by welding during a load-shedding episode!).
The battery charger is always limited to 5kW because of its 100A max rating - no grid blending is possible.
Does that make sense?

You can of coarse connect it to the output of a 3kva Victron with batteries. The PV inverter wll  then take the place of the MPPT in the system , that should be the most effective way of doing it.. 
Doing it that way, you will even harvest the sun while the grid is off. 
If the unit is too old, and without Sunspeck, you would need a Carlo to tell the ESS what the PV inverter is generating. (it is needed for control) 

15W for the lamps, times 8 hours, that is 120Wh.
48W TV for 5 hours is, let's just say 50*5 that is 250Wh.
Total required is 370Wh. Add in inverter efficiency (85% to 90%, if we're not too optimistic) and that gets you around 460Wh. Times two, because you only want to discharge the battery to 50% (assuming you want to use a Lead Acid battery). So you need about 900Wh of battery. Divide by the volts. If we assume 12V, then you need roughly a 75Ah battery. Might as well aim for 100Ah then, those are easier to find.
To recharge 460Wh, in SA you have roughly the equivalent of 5 hours of peak sunshine, so you need to get around 100Wh into it for each of those hours, which means you need a minimum of a 100W of PV. Again efficiencies come into it. If you're using a cheaper charge controller, add 30%. Also, if you use lead acid, you really want to be finish the bulk phase around 2PM so you have plenty of time to float-charge the last few percent, so better to err on the side of bigger.
A 100Ah lead-acid battery should ideally charge no more than 15A (20A if you push it a bit), and 15*12 = 180W. So you want PV around the 150W-180W bracket, in my opinion.
Now it gets even more interesting. Again, I assumed you want to go 12V (at such low power levels that would be the way to go). For that you ideally want 36-cell solar panels, because they make around 18V at peak power. So when you use a cheaper PWM charge controller, there is less wastage. Above 150W PV modules tend to be 60-cell or 72-cell combinations, so this again cements the 150Wp panel choice. It's about the max you can go anyway, unless you upgrade to an MPPT charger so you can use higher-voltage panels.

Give HomeAssistant a try, if you haven't already. It makes controlling and automations all the smart devices much easier. I have ICC sending data to my HomeAssistant to then automate stuff based on PV production and inverter mode etc. 

I'm new to the forum but I've been getting sent here by Google more and more so it was time.
Very interested in giving less money to Eskom (my employer, for my sins) and started automating and tweaking more and more in lockdown as I'm working from home. Where I'm at at the moment:
Water heating by 2 solar flat panels with 150l geysers in series (professionally installed) with a 5l/min gas geyser downstream when needed (self installed) Currently manually controlled but automation is in its future.
Electrically I'm on a 5kVA Axpert (whole house except jacuzzi) with 2kW of solar and a 3.5kWh Pylontech, watched over by an ICC Pi. All self installed about 5 years back. I'm new to the Pylontech and ICC. One day when I'm big I'll get another battery and more panels and stay off grid at night.
Downstream of that I've been playing with a multitude (mess) of cheap Chinese smart bulbs, Sonoffs for other lighting and jacuzzi control, Sansui smart plugs to make the coffee and a Broadlink RM Pro for the AV stuff and ceiling fans. Loosely and unreliably bound together by Google home. I can still more or less understand this lot so I'll doubtless be complicating it further soon.
Future plans include integrating the ICC into the automation. in fact automating and linking everything that will stand still long enough. And more solar and batteries, and world peace.
 

Hi guys,  I've been a lurker here for a long time now.  My utmost gratitude to all those who are willing to share their expertise, knowledge and experiences.  It helps plebs like me understand how to split the atom so much easier!  Yeah right!
 
So to get right to the point, I have reached a stage (not alone by my websurfing results) where my relocation aspirations have been hoodwinked by some sort of covert virus.
 
I've also decided that I'm now getting tired of paying for "freeloaders" and just outright thieves.  Time has come to start the journey to being self sufficient.  (Heat pump was installed today)  But where I need some input from the more informed and infinitely cleverer members then I am is with the next phase of the process.  This is phase 1 of the project:
"Canadian Solar 405W Super High Power Poly PERC HiKU 16.00
K2 Tile mount 16.00
Victron SmartSolar MPPT 250/70 - Tr 2.00
XXX Combiner & Fuse Boxes (2 X MPPT) 1.00
Freedom Won Lite Home 15/12 1.00
Victron MultiPlus II 48/5000/70-50 4000W Inverter 1.00
XXXX Bypass Box 50A Single Phase 1.00
GS50 Battery Installation Kit 1.00
Victron Cerbo Communication 1 Phase 1.00
Victron Lynx Power In 1.00 Balance of system 1.00
SSEG Application 1.00
COC Sign off 1.00
Installation cost
Electrical Work on DB - Splitting Circuits Commissioning "
The XXX is the installers own proprietary equipment.
This is to reduce my bill as much as possible and to instil a different approach to energy use in the other members of my household in anticipation and training for phase 2.  Phase 2 would be exploring electricity independence and phase 3 would be water self sufficiency.  
 
When looking at the above kit I see no obvious problems, just the price that needs to be considered here.  And of course that grey area called "installation costs".
 
BTW I'm in Cape Town and have a large hill behind me and a neighbour on the other side which reduces my sunlight hours in winter to 9:45 to 15:20.  Roof is East-West.  So system is attempting to reduce the effects of these parameters.
 
I don't want to give away everything at the first go so a few guesses would be appreciated to see whether these guys are in the same ball park.  And of course any other advice is always welcome.
 

So a tiny bit of an update, removed existing solar setup from all 3 DB's, 

Clean wall

So Step 1 in fixing solar... rebuild laundry.. 

Then design the shelf. bit of detail here for anyone looking to do the same.
My ultimate battery config would be say 10 pylon's.. thats 300kg, plus another 50kg in dead weight, which I wanted to do wall mount, not your average shelf...

Therefore, i used kitchen board from BoardMasters,
Most guys use aircon brackets should they do this sort of thing, but I ordered mine specifically from CabStrut. Each bracket is rated for 270kg and it was dirt cheap. 

So essentially, I designed for 2 cabinets of 600 each + wiggle room so board size of 1300.
Mounted on 3xCabstrut FPA350 http://www.cabstrut.co.za/cab-strut-cantilever-arms.html
2x pieces of 10mm threaded rod, for front mounting bits. which turned into something like this. 
6 M12 rollbolts

So thats is where we are today, and we shall see how far we get over the next week or so... 
However, please can I get an opinion of my DB board. 
Top row is for Panels, with a DC based surge arrestor
Second row is output, again AC Surge arrestors, 63A Isolator (out) and 2 earth leakages, split between 2 houses, I would have gone 3, but the guys that did my install lied to me, it is supposed to be individual feed to both houses, but alas, it is joined.. No matter though, so 2 external loads, EL for each, 63A
And bottom row of course is the AC Input, 63A isolator, 63A breaker for change over switch, and 2x32A for each inverter, 10mm wire for everything, which is overkill.
Whats the verdict, will this pass muster ?

 
 
 
 
 
 
 

Jy word gerook hier... A US3000 is around 20k, maybe a tad over. A U2000 is of course less than that.
I like the Mersen ones a LITTLE bit more... but I think they are pretty similar for the most part.
The batteries have a recommended max discharge of 35A per unit, or 70A for the two. 35mm^2 is ample for that. But... you have 10kVA of inverter, and the battery can deliver 1C for several minutes, or 140A. 35mm^2 is good for that too. Just ensure the cable length is as short as possible, and that the voltage drop is 1% or less.
I must say... well the folks around here know I'm not fond of the Axpert inverters. Well, truth be told, it's not a bad design... or rather, it is not the worst design in the world. But one thing I don't get, why does everyone install TWO of them, and then completely under-battery the setup? 10kVA of inverter, but only 200Ah of lead-acid battery?
I mean, it is so bad, if you walk in the door and you see two modules on the wall... you can be about 80% sure some idiot installed it with too little battery capacity. It's almost a cliche by now...
I digress. Yeah 35 should be fine.
Size the fuse for the cable, not for the load. 160A is good for 35mm^2.
Are you talking about these?

This is the cheapest DC clamp meter I could find, at around R1500. I've had it two days. It appears to be fairly accurate, at least, it measures to 100mA the same as my battery monitor. It's very plasticky, but it has a backlight... and since I don't do this every day, it seems fine for my purposes.

Just be warned! During load shedding babes is going to watch her favorite program, and you might end up running around like a serious operator monitoring battery view, inverter, watchpower, ICC and whatever to try and not look like the fool who spent that bucks on the rabbit hole😁

In my opinion, the best hybrid mode is "Grid Tie with Backup II".
Eastron meter is needed in order to get this mode to work correctly.
In this mode, the inverter blends Grid+PV+battery power together. It allways try to compensate grid to zero:
If there's too much PV power, the inverter lowers it's output in order to reach zero export. If there's a huge load on the backup or AC side, the inverter uses PV first, then battery, then the grid. You can also limit the amount of Power (watts) that will be pulled from the battery. If there's a need for more power than this limit, the remaining watts will be pulled from the grid. Logic:
If you have some loads connected to the AC IN side of the inverter, these load will benefit from the PV, Battery and the Grid too. Once the grid is down, these load will go down too. They are not backed up. These load can be huge, there's virtually no limit on Amps. Whatever is connected between the grid and the Eastron meter, will NOT benefit from PV, nor from the battery. If you have some loads connected to the AC OUT side of the inverter, these loads will benefit from PV, Battery, Grid. These loads will be backed up even if the grid goes down. These loads have a current limit of approx 21A.  
For a shame, this mode does not work with NetMetering because it aims at 0 export. If you have an excess power generation, fully charged batteries and small AC loads, the inverter will lower it's output.

If you want to use NetMetering, the best mode is "Grid Tie with Backup I"
In this mode Eastron meter must NOT be installed.
The logic is very same like in the previous mode, but with two exceptions:
All the loads in the house will benefit from PV+GRID, no matter where they are connected. If you have excess PV generation, all of it will be fed to the grid. In most of the countries, there's a limit of roughly 3700W set in the inverter's configuration.  
Feeding the battery to the grid
By default, feeding the battery to the grid is disabled in all the modes. However, if you really want to, you can manually tick "allow grid feed-in" + "allow feed-in battery to the grid".  Then the inverter will send all the excess PV generation to the grid, up to a defined limit (normally 3700W). And if there's not enough PV, it will discharge the battery to the grid too. Again, up to a total limit of 3700W by default. For a shame, it's not possible to control battery discharge based on the SoC. It simply discharges the battery up to a point where the low-voltage threshold kicks in.
 

Keep in mind that this inverter runs in grid-interactive mode and therefore all loads (whether on the input or output side) is actually powered by the grid while the inverter behaves like a GTI (except during an outage). The decision the inverter has to make is how much energy to push back.
When you use the internal current sensor and disable feedback, the inverter "feeds back" just enough power to power the devices on the output, aiming for zero on the input. When you use an external modbus meter (and disable feedback), THAT meter replaces the internal current sense and now it will attempt to feed back enough power to zero the external meter. Any appliance living on the input side of the inverter, but downstream from the modbus meter, can then benefit from surplus energy. This would include the geyser and stove and all those heavy appliances you normally leave on the grid.
In other words, with Wetkit's setup, the inverter counter-intuitively feeds energy back from its input to the rest of the house, but it still attempts to avoid feeding it to the grid because you told it to.
Of course the additional delay of communicating with the modbus meter also comes into play.

??? WTF?