Mad Mike

McGuywer, my take for what it is worth... your mission statement is to reduce your electricity bill, focused which is great. Get either the solar water heater or heat pump. That right there as a rule of thumb about 20% saving on your current bill. Though not popular.... (I have my helmet on for the stones that may be lobbed my way!).... buy a petrol generator and if the budget allowed a diesel generator. This will get you past the load shedding hump in the short term. I can tell you that even with over 30kW of battery storage, Eskom has pushed my little system and after a week of continued load shedding I have had to run the little gennie during load shedding to give the solar time to fully recharge itself. Granted my panels have lagged behind my battery capacity but roof space is also limited. Get the largest capacity inverter you can afford, a 3kW is nice but small if you intend to make a dent in your eskom bill. Add your solar panels and batteries as the budget allows. You will most likely run out of roof real estate long before the budget is exhausted! Batteries will be your albatross,l but an investment worth making if you cycle the batteries everyday and do so agressively. I actually started with a single 2.4kWh pylontech and it would be flat every night by 10-11pm! Budget limitations meant that I change my approach to increasing capacity, so I started down the DIY path and started building my own batteries. Enjoy the journey it will be very exciting.

Avselm, it may be worth a shot to reduce the circuits on the backup side of the inverter and slowly (over a hours) add them back. had a similiar issue and found that having all the lights was fine but when I added "essential" plug circuits in, the loads here and there quickly added up tripping the inverter. Goes without saying I had to redefine essential.... Long story short the 5kw inverter has only 25A limit on the backup (older inverter) and this ceiling is not that high when wanting to power everything because you have enough storage! SO I have two Goodwe inverters now to share the backup load.....

Excellent options have been tabled but the immediate "the look" solution has not been proposed! I will put on my hardhat for this one and run after.... I small genie (+-ZAR 9,000) is your friend, to tide you over this initial phase of tidying up you DBs, rationalising what loads will be essential, planning the hotwater solution and finally deciding what your first (rev A) of your solar solution will be! The boss wants lights, TV, internet and possibly the kettle working now! granted the genie will get parked eventually but as a stop gap measure it cannot be beat! It worked for me and even now when we get eskom's special extended loadshedding events after the scheduled events and mother nature adds rain and cloudy weather for a few days on a trot, I have rolled the gennie out to get past the worst of the outages!

unfortunately not! I pressed the unsold ones into service testing my own batteries. I am planning on getting a few more some time in January 2022.

Finally got my second Powerwall nearly done, need to tidy up the wiring and fabricate the panels to enclose the battery then to roll it into its new home in a little fire proof should it loss its mind and go nuclear on me! But so far so good. As with the first Powerwall it is a 14S setup but only 240P. the usual... finding of the used 18650s, testing them, soldering and fusing every one of the cells brings tears to my eyes and sweet words for each cell done! I will hopefully find a few more of the pictures taken at various stages through the last 12 months and post them here. IMG_2526.heic

Let’s just say that the batteries haven’t don’t anything in the way of burning their fuses, pulling the packs out of balance or burn down the house in protest (knock on wood). the exercise of soldering the individual fuses still brings back flashes of hours spent bent over swearing at each cell and the accompanying fuse! when I win the lottery I will be buying the kweld to spot weld the fuses on....

@DanieT I suspect that the nova blue batteries aren’t on the compatible list for the Goodwe (the list is very short unfortunately). If my assumption is correct then your installer left the system in the “best” working condition. the Goodwe plays nice with the battery when it can “talk” to it. In the general mode you will experience situations where the battery % will be very errantic and the inverter will for instance go from a 90% reading and drop vertically to 10% when discharging. You may see the same behavior when charging. my personal experience has been that to get round this problem I have had to oversize my DIY battery. But even then after 2-3 days of rain I will still hit that wall and the inverter will dip and then shutdown ignoring the 30% cutoff I set in the Goodwe battery setting. in short it is possible to use the general mode but your expectations and wiring may have to change to accommodate the new normal behavior of your system. hope my rumbling answer has helped. Happy to share specific experience if you are going to change your settings...

waving my hand(s) vigorously for the dishes if they are still available.....

Hi, I have 2 left.

@Allsorts the Goodwe inverter does not mess around when it comes to limiting the output on the backup side of the inverter. If I remember my manual right there is a 10A limit and the 2.3kW limit to contend with. The backup side of the inverter I have found is happy on-grid and off-grid (load shedding) when I have kept my lights and bare essential plugs on it. This would be the fridge and freezer, TV and internet. anything else like the microwave and other general plugs just creates an unhappy inverter. the "heavy appliances I have left on the main circuit and the inverter happily feeds them power there (excluding those nasty start-up peak loads). the only down side is that during load-shedding those plugs are unavailable. but as I have found during load shedding the wife and kids are happy to have their lights, internet and TV going and will gladly suffer the indignity of no AC, microwave for 4 hrs.

I have been asked how the battery pack has been behaving thus far and i think the only way to really show this is to share the inverter logs from Goodwe. I have shared from the 20th of this month the day after I put the system back online. Just a few notes to make; the house has been split into two main circuits (that job was a revelations of the rat's nest of wiring I had in the ceiling and original DB) with two independent inverters. This DIY battery pack supports 50% of the house and all the security and perimeter lights the second inverter supports the living space and kitchen, that one I haven't made any changes to yet. so that said the DIY battery has been chugging away nicely and the supported load have been 100% solar and battery supplied (ESKOM has been officially given notice to vacant that space!). I am extremely happy with the outcome and now I am truly motivated to tackle the second battery pack. I think I will have a "lightly used" pylontech battery for sale within the year! PV status.pdf

I have actually done the cost on the project and let's just say that it isnt cheap.... Let's Assume an R450/hr labor rate Shelling the laptop batteries and cleaning the 18650s 14hrs (here I assumed that even the low capacity cells were going into a low capacity powerwall eventually) = R6,300 Capacity testing (just the loading and unloading into the testers and labelling 1 min a cell - actually timed this...) 18hrs =R8,100 Soldering batteries packs 28hrs =R12,600 Cost of 18650s @R5 No 4480 = R22,400 Miscellaneous (welding cable, soldering guns, solder, fuses, 18650 battery holders, server cabinet, rack, busbars, BMS) R=10,000 so for my theoretical 33kWh ( have conservatively derated this to 28kWh) powerwall I am R59,400 in the hole and counting! if you take out the labour of love and pain cost..... If you look at Revov for secondlife batteries 10KWh is R45,000 so 30Kwh would be R135,000. It is a toss up as to whether zero warranty (ie you are the warranty) is worth paying a third... so far I would have to say i am pretty happy with the outcome so much so that I am prepping for my next build. I definitely want to build several Tesla type (in form factor) powerwall to use on my second Goodwe inverter.

Thanks for pointing me in the right direction! I will definitely go and whine and complain there.

@Louisvdwnow that I have you on the line, the app has a limit on the Ah that the battery can be..... my little battery Has put on a little weight and now has a theoretical Ah of just over 9400Ah. Any chance that your next update to the software would accommodate us outliers? Pretty please!

Hen’s teeth and honest government will come first I fear! But I live in eternal hope that you will see the error of your blue ways and come over to the yellow side (drivers, cables and battery bits in hand) amen!