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Matts Brisbane Powerwall
I thought I'd start a thread here with the details of my powerwall and system. No photos just yet, but they will be coming soon.

Before I started I already had a commercially installed 5.5kw solar system. It was as cheap as I could find, and at $3400 AUD installed, was right at the budget end of the scale. So far I have been pretty happy with that system, and I reckon it is close to break-even in another 6 months or so.

After a great deal of research and watching videos, reading, etc as well as trying to source cells (constant battle, and getting harder as more people get into this hobby), I settled on going hybrid. I didn't feel like I had enough confidence or battery storage to be going off-grid (effectively isolating a set of circuits onto battery power). I also didn't want to be mucking around with switches, etc. I just wanted to program the system and leave it to do it's thing!

The hybrid inverter I chose was the 5.5kw MPI hybrid from MPP Solar. I ended up getting the modbus card (I'm still not really too sure what this does or if I need it/can use it), and the energy meter. I figured if I buy everything offered, I won't figure out later that there is something I needed. The inverter was something like $1900 with everything and shipping to Oz. So far I'm pretty happy with it as it has 2x PV inputs at 500v for up to 6500w of panels. Some of the cheaper inverters were much, much lower voltage input, meaning more losses and harder panel installs. This model also met the AS4777 grid standard and can chose a load of different preferences (grid tied with export, off grid and hybrid). With the hybrid, i have set it to only charge the batteries off the PV input, but it does have a 60a AC charger built in as well. So far I am pretty happpy with it. Full manual if you are interested.

I have 10kw of Li Ion installed after several months of shelling and testing batteries. They are going ok, and I used Repackr to match capacities, but one of my packs seems to be much lower capacity than all the others, so I will investigate that shortly. Could be blown fuses, or just needs a rebuild. I am 14s80p and am using Pete's metal wall mounts (I need to buy 2 more shortly by the way Pete for my second 10kw). I soldered the packs, but this was a monumental PITA, if I had my time again, I would have bought a spot welder, that looks wayyyy easier. I used fuses on my positive side, and strong TCW hookup wire on the negative side. I used 6mm house wiring cable for my busbars. That seems to work pretty well. A few mistakes - don't buy super cheap solder from China. It's definately false economy! Also, get a big-arse soldering iron. Higher wattage definately made my life easier. I also brought some cheap butane gas lighters off ebay to get heat into the big battery connections when soldering.

I chose Batrium as it seemed to be the gold standard and what the "big boys" use and recommend. The price certainly was eye watering, but all the components by themselves seem pretty reasonably priced (but you just need a few pieces to get a fully featured system). The Batrium system is good, but this forum seems to be the unofficial support channel as documentation is very very scarce. I brought the Watchmon4 and the state of charge sensor as well as 14 lonmons.

I used the ABB SACE 200amp breaker with remote shunt trip. This seems pretty good, but it's pretty industrial! I have also got an HRC fuse holder on my bank with 2x 160amp fuses in there. In hindsight I probably don't really need these as the breaker covers it off, but in future when I add a second 10kw bank, I will be able to isolate one with these fuses.

I have just picked up 10 second hand 250w panels for $250 AUD, which I thought was an absolute bargain! It is middle of winter here and my yard is pretty badly affected by tree shading, but they are producing around 80% of their rated output in the middle of winter over here, so I think they are close to their rating, but only Autumn/Summer will confirm that.

Will follow this up with some piccies later
Very nice and Well thought out. Thanks for posting and Get some pics up eh
******Hi My name is Jason and I have SOCD (Solar Obsessive Compulsive Disorder)*******
Current Powerwall - 1400 Cells 7s200p (modular 40p packs) ~ 12kWh of storage     4x 315W Canadian Solar Panels

Working on the next 7s40p packs     ~2.5kWh

Waiting on 2000 Cells of unused Sony vt4 (2000mah 30A) ~ 15kWh      hehehehehe  More Power

I am not too sure why the photos are around the wrong way. Stoopid iPhone....
Redpacket, Geek, jdeadman And 2 others like this post
Looking very neat Matt!

Do you have any more detail on how you've built the wall mounts for the packs? They look solid.

Quick one on the longmons, I thought they needed to be attached to the cells themselves to give accurate temperature readings? Have you had any issues with that?
(06-29-2018, 12:54 AM)John Allen Wrote: Looking very neat Matt!

Do you have any more detail on how you've built the wall mounts for the packs? They look solid.

Quick one on the longmons, I thought they needed to be attached to the cells themselves to give accurate temperature readings? Have you had any issues with that?

I got the wall mounts straight from Pete (HBPowerwall). On his official build page (I think it's sticky up the top of the builds section of the forum), I think he shares the drawings if you are not lucky enough like I am to be able to drive around to his place and pick up some pre-fabricated ones. They are folded steel that are powercoated I believe. They are really solid and well made. I have heard of some people making them a bit longer and going for 100p instead of 80p.

The longmons have a cell temp sensor on them, but I have never really had my cells get very hot (although it is winter here atm). My inverter has a 3kw charger built into it, so that's 62 off amps over 1120 batteries, so at max output that is 0.05amps per battery if my maths is correct, so I doubt I will see them getting very hot with the current of charging.

In terms of 'heaters', hopefully I have weeded most of those out with my testing, but I do have a thermal camera that I brought and will be on the lookout for any bad cells.
Looks good Matt
Where abouts in Brissy are you?
I’m Burpengary way, I’m still checking cells & hope to have my first 10kWh done by the end of the year.
Are you still chasing batteries, guessing you are but I’d be interested in contacts if you’re not.
Thanks for writing up your project. I'm looking to do the same thing and trying to get my head around what the hybrid inverters do and don't do.

1) Does the hybrid inverter sit between your whole House/Grid/Batteries or does it power a subsection of your house?

2) And what happens in what situation at any point in time (depending on your settings):
-More PV inbound than your house is using
* If the house usage is less than the inverter capacity -> power house + top up batteries + send to grid if batteries are full
* If the house usage is more than the inverter capacity -> top up the batteries with PV and power the house from the grid (or can it mix a bit of PV and grid to supply?)
-Less PV inbound then your house is using (night time)
* If the household usage is less than the inverter capacity -> if the battery has power use it if not use the grid (or can mix grid/PV power)
* If the household usage is more than the inverter capacity -> use the grid (or can it mix )
I didn’t think ANY MPP could be grid connected in Australia? No approval?

How much was the ABB?

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