Mad Mike

Jaaks which one of the boxes are still available?

Just a little update here. I got my Chinese BMS with a RS485/RS232/UART output and connecting that to the Goodwe battery BMS port the Goodwe has began taking a SOC reading from the BMS. The SOC charge "jumped" from 49% to 68% which was more representative of the powerwalls state.There is still the BMS communication Fail error. I will see if this baby step improves the way the Goodwe inverter and the DIY powerwall play together. I may have to do a bit more fiddling... Will check back in a few days....

I am now sitting on the 20% reserve! The panels occasionally kick in and push some power but with this rain Eskom power has moved back into the house..... If Eskom does finally catch up with me and loadshed my area I will give the gennie a work out, she has been ready for months! she may also get a better muffler and sound box to keep the neighbours happy in the near future.

Go ahead rub it in!!!🤣

@Bobster if you are looking to introduce the weekly and daily timer to your pool pump maybe consider get the low amp timers (they now have the touch screen type ones) and use that to activate a contactor that will and can manage the current surge and if your pool pump has a high initial startup current that would otherwise quickly burn out the timer.

Shame! I see the geyser owning a shade at your expense... old blanket to tuck the tubes in for the duration, but that would be a sight for the neighbors to behold!

unless you have a very specific need for configuring your pack to a very specific set of requirements, and have it "talk" to a clever inverter i would throw a Chinese BMS at the problem. run Buy 2 and have a spare just in case. I have read of any of the BMSes dying in a connected mode and letting the battery runaway from you. I have seen then just die and stop operating as the default. you then can get a bluetooth app for some of them that you can do some rudimentary settings (max and min cult-off voltages, parallel pack voltages setting) and monitoring. I have one BMS on my power-wall, the packs were built fairly well balanced (I used Repakr ) but I do check my packs twice a day everyday and they have behaved so far. The BMS does get a fair work out top balancing my packs if the packs have been through a few days where I have thrashed them, then they do begin to drift apart and the BMS has to even it all out for me. If Chinese isn't for you then the Batrium a excellent option and I have it on my wish list! I am hoping Santa decides I have been a good boy and lets me buy it for myself... @Seant had a Batrium installed on his power-wall and was very pleased with its performance .

I am dripping with green envy!

if you are leaving the house unoccupied then I have found having the circulation pump run for a few hours in the night (I personal have mine run 2am-5am) cools off the water in the tank. it then runs its normal heating cycle during the day.

I tried a local supplier early on and was massively disappointed as the items were fakes and died within days. I bought mine from china and have no complaints, the 4 units have tested just over 4500 cells between them. They are now showing their age, buttons not responding, afew bays are temperamental!! I have ordered new ones from China again and if the post office staff don't liberate them from me prematurely I should have them some time in January 2020.

Just a wee bit! I have a sweet19kWh powerwall up and running a small 3kWh power wall on the way for the other inverter. Don't tell the others (I am shooting for 50kWh), they think I am crazy by building a fireball in waiting!

@San Chan, I would recommend you go ahead and buy something like the liitokala units to test your batteries. they will give you the Capacity, and internal resistance of your batteries.

Hi Xinath, the Goodwe inverter has a feed-in side (non-essential loads that are not supplied if Eskom is gone) and a Backup side (essential side that continues being feed when you are load shed. From what you have described your sparkie has at best connected everything to the backup side of the inverter..... the inverter if it is the 5kW has a load capacity of 2.5kW on the back up side, so you would be pushing your inverter hard on the backup side to keep your house powered. If the load and backup are connected to the same load I would hope that the system trips otherwise you could be damaging your not so cheap inverter or worse feeding into the grid (the inverter should trip itself and go into a safety mode...) I see cleverer fellows than I have given several different options on spreading your load , I would only add maybe look at adding a solar water heating system. This can assist lighten the load on the inverter by doing most of the preheating of water during the day most days of the year and you just need to top up with PV/battery power on the really cold days. on my DB i have split it the circuits that keep the family essentials going (lights, security lights, TV, internet, fridge, microwave, garage door, alarm system and electricity fence) going. with this setup my battery bank can run through the night no issues.

@Daranger did you ever come right with the Goodwe and "non intelligent SOC-wise" batteries? I have been running my 5086EM in the economical mode for about a month. I experienced the same issues where the inverter would report the SOC at 6-9% then jump straight 100% before it would the cycle until a large load would drain the battery and it start the whole sordid process again! Economical mode is working for now.... Maybe there is BMS or some clever SOC measuring and report device out there that would talk to the Goode inverter....

Dex, when i do get to the point that there is a small lawn growing in the dust and I have mowed it a few times I will definitely that a picture!

The only issue I have had with the "face up" orientation of my pylontech is that the face is picking up a lot of dust. My garage isn't as dust proof as I would like ... May change the orientation to put the "face" on the side just to keep it cleaner.

I have 2 150lt geysers and install a vacuum tube system from hudu (franchise is long closed.. story for another day) the 18 vacuum tube system with a 12v solar circulation pump heats up the water most days of the year just fine and my heating elements in the geysers only work when I have guests over or Someone takes a long shower off the agreed schedule! the system paid itself off in less than six years. It cost me 18k back in 2009.

The busbars are cut and drilled! The system is back up and running. Suffice to say that it was much easier in my head that it turned out to be. still need to tidy up the BMS wiring. The solar system has been running now 5 hrs powering my lights so I am as happy. Tomorrow will see how it charges up. Afew lessons learnt for the next build! This system I think I will leave alone to do its thing for a while. I like the server cabinet and i will definitely build the next battery pack to fit more space effectively in it! So now I start the hunt for 4000 odd cells to build that battery (a year plus effort unless I fall into a solid source of used batteries!)

After a lot of trial and error I think I have a plan packing the batteries together. I have built 7 boxes to hold 320P. This will allow me to fit everything back into the server cabinet I have on hand. Next I need to attach busbars to which battery bank apply the covers. Once this is done it is fingers crossed the boxes will fit and the system goes back online this weekend.

I believe a search for glass fuses should do the trick. There is a wide selection from 0.5A going up. I opted for 3A fuses just because I didn’t planned to push the cells hard . My please was to draw less than 0.3A per cell at peak. So the 3A was to protect again a cell going into reversal or self discharging spontaneously. https://m.aliexpress.com/item/32856407960.html?pid=808_0000_0109&spm=a2g0n.search-amp.list.32856407960&aff_trace_key=54b2b84d62464e49aca10a79cc6fa149-1566282451495-03342-UneMJZVf&aff_platform=msite&m_page_id=8998amp-v3eOzPG_HFh-lg0NQMce2g1566282476878

@Gerlach , you will have to forgive the untidy soldering! the battery holders are also off AliExpress. I used the 4x5 pieces. Lost 2 orders courtesy of the post office. I did get a full refund from AliExpress but the time lost and exchange rate losses....

Since you have asked so nicely..... 🙂 I will.

The BMS is very rudimentary, it has no user interface. The seller indicated that it top balances at 4.1 volts and cuts out at 2.8. I have charged beyond 4volts (28.7volts) and my inverter cuts out at 2.85 (20Volts). As for the balancing I think it works but to be honest the batteries were never out of balance when I run the system for a month without the BMS! For the first month I checked the battery packs twice daily (morning and evening) and everything was working well. I will say here that I used repakr to build the packs so they were for all intents and purposes all evenly matched.

@Gerlach, I will post better images this evening for you.

the good times keep rolling! since my last update I have added a cheap Chinese BMS and 4 330W Canadian panels to the 2400W Home UPS 3.6k inverter. I have cycled the setup literally everyday charging up to 26-27 volts and discharging down to 20V. that has been a manual process of turning the inverter own flipping the breaker and through interlocked contactors (so that I don't burn down my pride and joy) running one half of the house and security lights every evening for between 3- 5 hrs. this has run flawlessly and the packs have remained within 0.02V of each other so far. just finished cracking more laptop batteries, testing the cells and building another 7s 160p (built as 14 packages of 80p). I have dismounted the first 7s 160p set i built in May this year, and currently have them all sitting on the floor connected in parallel slowing balancing themselves out. this now brings me to the grand total of 2240 cells averaged at 2000mAh each. There is a set of cells that range from 1600-2700mAh (average is approx 1800mAh) seating in the garage that would potentially give me a third 7s 160p pack but I have my doubts as to whether it will fit in my cabinet with the rest of the other 2 battery banks. for now it will wait. the highlight of the day yesterday was letting the magic smoke out of two pack fuses by accidentally shorting the packs (nice spark!). That was a 90min job to redo 160 fuses but on the bright side I now know that the fuses work.... I hope to have them all balanced in a day or two before remounting the whole thing back in the cabinet over the coming weekend. then I think i will start the monitoring phase of this whole exercise and see how much money this whole exercise has cost and what it is saving me (apart from the drinking money saved by spending so much time in the garage soldering iron in hand!) I will post a few pictures in the coming days.