TheMafiaMan - NotMuffinMan

Hey Bobster, I hope you don't mind the question - I know from reading another thread you've had many dealings with the whole COJ SSEG process - what are your thoughts and in so much the info you can share with regards to implications, costs you might be aware of and therefore paperwork involved in not having any electrical supply at all? I'm on Prepaid. I've been told, provided info, bits and pieces of nonsense side chatter and various 'scenarios' ranging from they'll pickup that I'm not using and or buying any credits and send the City Power Gestapo to see you've not done something illegal (which I've not so then what?), to "its not allowed"; to you have to have a connection to your house as part of the municipal bylaws (I've never actually seen that exact wording) to it costs +-R2100 fill in a form at city power offices and they will remove the meter and deregister it from your erf/stand number; to you cannot sell your house along with many many others. If I'm self sufficient there is no law that I'm aware of that says I have to buy power from the incumbent government SOE or any IPP. Your thoughts? In my scenario by the end of this month, through a transfer switch, which currently interrupts my incoming city power and switches to my diesel generator, I will for all intents no longer be connected to City Power at all when I move my transfer switch to Generator only. I will be my own "utility" island if I may call it that. I wont be back feeding both from it physically being impossible i.e. no physical connection to the grid and I'm not interested in getting cents on the rand, for my capital expense to feed back into the grid. So my system will pose no hazard upstream to utility workers or my neighbours. I've slowly built out my system since 2022 first with Inverter and storage and the generator I already had. I now have a fair sized array of 8kw with I hope, all the best of the scenarios, like no shading, facing perfectly north, on a 30degree slope etc. Its having some final work done. An 8kw inverter; 12kw+ of storage and onsite the generator room with a 6.5kva diesel generator and enough diesel to run for 1-2 weeks and indefinitely if I had to. (1.3ltr per/h for 5kw or +- 80% generator load), This will replace for me my City power feed by choice. I can hear the keyboard warriors raging, typing furiously that electricity is cheaper than diesel - but is it really? 😑 - it serves my end goal - that's all that matters. I will use Solar during the day, storage to take me through the night and if needed on a poor generation day(s) top up the batteries or cross support the load with the generator only if needed, maybe 1-2hrs in a day, a few days a month - the last step will be automating the generator coming online and going offline based on time of day, load demands vs peak solar output vs current load as well as percentage of storage left before heading into sunset - the goal being to finish as close to or at 100% SOC- my December hobby project. I share others sentiment that all they are doing with all the nonsense they're dreaming up is making the financial case for me to add another battery maybe some solar in my case thereby saving me more diesel and service costs on my generator - the way I see it - there is no scenario for me and I refer to only me, where I need 'services' in this case power any longer, soon enough, if I have my way I wont need water either - they know this day is coming hard and fast - those that can sort themselves out - and those that cannot, well they can't afford to pay the ever increasing costs - its a lose lose situation for them - I pay large taxes, in the form of company, personal, food, rates and fuel levies taxes to name just the most common ones - sorry I benefit from none of them - I'm older and very much too jaded now later in my albeit mid-life to adopt the "its for the greater good of all my countryman" argument or perspective anymore. I'm not 100% sure about your school of thought about if you sell, then the purchaser might factor in a new connection etc. I don't suggest you're wrong, but I'd suggest another school of thought in that regard - that there is the right kind of house for the right kind of buyer - I know I can find a buyer that wants the freedom from utilities to a large extent, and the guarantee of their own clean water supply - that's a whole other interesting discussion. As always your thoughts and anyone else's perspective is always welcome.

It is sounding a bit like a the parallel setup is not functioning properly can you possible post a picutre of the screen of your two inverters on the section which shows master/slave settings? one inverter would be setup as master and one as slave. Do you have one battery connected to each inverter or both going to one inverter? The switching you're descripting does it sound like a solenoid type switching on the battery end or is it on the inverter(s) side? Sorry for so many questions - the more info the better someone can help - i might not be able to but at least we would have more info to try figure it out if its only a settings issue ...

Hey Christo - Remenisent of my CFE batteries cycling between 90-100%, then 95-100% after a firmware update then pinned at 100% after yet more updates - i'd look to get an official explanination from the manufacturer/importer and maybe your installer can help shed some light as well...maybe check that the parallel connection is working as expected - i'm assuming you have no errors stored? - also you don't mention if you have solar installled or not?

On the 8 August 2023 @ 11:00 am, my CFE debacle came to an eventual end - the saga if anyone has interest or wants to see the history HERE I would love to be able to say that the many many hours of trouble shooting - help, comments and questions from numerous forum members like @HendrikBigChief for analysing endless graphs and reports - much appriecated your advice and willingness to hear me out and offer solutions to look at, @Zak @I84RiS and others i'm sorry if i forget to mention you, not least being banned/kicked out from a CFE whatsapp group (what a misreable lot) resulted in the problem batteries being sorted out - rather the situation with the CFE batteries got so bad that no load over 2000watt could be run in BMS only mode (which i'm sticking to my guns on is how the batteries are supposed to be run) without getting F56 errors F26 errors the list was endless - CFE where unhelpful eventually flashing the 2 batteries at least two more times and then proclaiming that it was the inverters firmware that was the issue - we (SolarAdvice and I) relented and got DEYE to push an unneeded but never the less non-problematic firmware update to my 8kw inverter for only the exact same things to continue happening. (just a note we did try to run the batteries in AGM but we couldn't get more than 30min reliably in AGM / manual settings without both batteries tripping out even when idle and not under load) I had to travel for work and its been more that a month but it had already been agreed with SoalrAdvice that we had exhausted all options - they really have been no nonsense about exchanging them - the delay was more from my side to exhaust all options and mostly my patience. But its the batteries and thier bad BMS. The contenders where Solar MDs 14.3kw(single battery) or two DEYE 6.14kw batteries and given Budget and my existing diesel gensets conversion to automation and final sound proofing of the generating room, just a few weeks from being completed, the DEYE where deemed the best compromise as the 8.1kw solar array still to be commisioned together with the Genset and automated system in place as well as low household base load means we'd be fine off grid. There is space being made for a posiible 3rd DEYE Battery towards December but right now the Genset project needs to be completed and Solar Commisioned before Feb 2024 to claim the rebate. Almost one week in and with Loadshedding back to 5-6hrs for us i'm happy to report so far that the DEYE batteries have performed flawlessly (fingers crossed of course) - even though we've only grown usable capacity buy 2kw or +-18-20% we're seeing different consumption/efficiency/conversion numbers running all the same loads as before and conversion/efficiency wise we're seeing an actual net gain of almost 25-30% from the batteries. I cannot say why right now and I only have 6-7 days data vs 255days data from the CFE's but something is different (time will tell if this a indeed a gain of sorts and i'll be monitoring it) - off the top of my head the only notable change is battery temps. the inverter battery settings have remained unchnaged and we're running in BMS mode with the inverter showing 00 & deye next to it under lithium - the CFE's always opperated between 27-35°C even at idle in a 21°C space - and loads even reaching 39-40°C - but the DEYE units are sitting @19-21°C under load, maybe there is a better thermal layout inside or better passive cooling but even now with them being on load for 2.5hrs during loadshedding and then charging @40A back to 100%, tempreture is 21°C and its notably warmer outside today. Time will tell is guess. I'd just want to again mention that SolarAdvice where champs in getting this all sorted from the re-order, allocation, booking a team to do the swap/install and keeping me in the loop the awesome two guys (cannot remember their names) that did the swap out and wall mounted them for me without makign a mess, breaking anything and just being really pleasant to chat to - this business is doing this right and all my interactions with them over the last 7+ months has been consistently excellent - they're patient and I know I can be difficult - but there was no need to be as they where just really professional about dealing with all of this - highly recommend them. I'll post an update in about a months time and again am happy to answer any questions and hopefully keep up and contribute info to the forum - theMafiaman - out.

PS the BESS app shows all 16 of my cells in each pack to be at 3.32V most of the time As of right now the master battery is 16 cells @3.32v my slave battery has 13 cells @ 3.32v and 3 @ 3.33v - even when I've had the weird drops and such the cells are all according to the app fine and within normal range - and I've never had the actual pack go into a full on fault mode other than once for a low voltage level 3 fault when they where completely drained and we had no power for 12+hrs Anyway I hope you fair better

Welcome @New As you can see I've not had a great experience - your SOC cycling between 90-100 suggests 2 firmware version earlier than mine now after 2 updates - mine did that originally - purchased in Nov 2022 you can see in the post how to determine which batch and version battery you have but if you bought it in the last 3-6 months its the v3 most likely - mine is too. My advice - don't update the firmware if you're not having any issues - I hope unlike me time doesn't paint a different picture - if you can get below a 20% SOC then you're already better off than I am, whenever my batteries hit 40% SOC they'd drop to 7/5/1% in 2-3 minutes. Maybe as a caution, C rating doesn't stack as people think it does - I've seen multiple installers, resellers etc. say that 2 x 0.5C batteries gives you 1C. That is not correct. Assuming you have 1, 4 or 8 of the same battery rated at 0.5C your storage capacity is doubled, quadrupled etc. but in essence if you want to realise that stored energy as efficiently as possible then you would need to use it at 0.5C or even possibly 0.25C Basic rule" C rate doesn't stack in Series In parallel connection the C rating is wrongly attributed to stacking the load because you're "1/2 ing" the current between for example 2 batteries - think of it this way the faster you discharge them "Higher C rating" the less electricity you get out over time. At it's simplest Its the electric car example - lets use a TESLA - freekin quick but if you thrash it in 01-100 launches and max performance pulls what happens - batteries overheat and your range i.e. usable storage disappears and becomes much less. fast = more power, more power = higher C rates 2C, 4C 8C etc. I used to in a previous life fly large commercial load-bearing drones - we'd have large LIPO packs that you could pull/discharge at 25-40C for about 2-3min in specialty situations and then they'd unceremoniously die or you could fly reasonably at 8C and get 10-12min If you where unlucky your drone would plummet out the sky or if you where a good pilot you'd monitor voltage and current like a naughty kid in a park and landed it just before it was about to expire - I was one of those pilots that was careful and I have only ever lost one drone - I "infamously" drowned a very large, very expensive drone 10yrs ago that had a faulty BMS and I ignored the V and C rates for 5-10 seconds - it landed itself in a large dam - police divers had to come fish it out. Needless to say my "employers" where not happy with me - however telemetry data proved I wasn't reckless and that the BMS went "offline" about 15seconds before the drone became "unstable" - the lesson applies though. 200AH batteries discharged at 2C will not nett you 200AH worth of energy. CFEs own data is misleading - an older manual states 5000w/3000w nominal i.e. 0.6C, the sticker on the side says 100ah or 1C and newer docs mention neither other than 1C charge and discharge - they cannot seem to decide which one - I would have to advise based on my experience that you treat them as 0.5C for charging and discharging. My beef with them is CFE sell there batteries as 1C charge and discharge product - It cannot in my case reliably do 1C between the 2x 5.12kWh batteries and in Lithium mode the batteries die in 17min or less - now whether the SOC is wrongly calculated, comms are faulty or my batteries are not charging fully or discharging, I don't know, but we cannot spend the type of money we do on these to tinker - If I wanted to do that I'd build my own battery packs. My advice after 7+months - there is no need unless a once-in-a-blue-moon emergency to charge your batteries at 1C - 100AH, i'd recommend not acceding 0.5C or 50A and I found 40A is a nice middle ground leaving your inverter some headroom to run other loads when charging - again ideal on a 8kw invert but I'd drop that to 20-25A on a 5kw inverter.

HI @HendrikBigChief tried this morning as a last ditch effort to put the system into V mode as you suggested - it would seem since the latest firmware update I cannot do this any longer as the batteries once booted up, inverter restarted and connected back to the batteries - immediately trip into a fault mode when the inverter initiates the connection - so SOL. Thanks - I know you where try to resolve my problems and at least see what the batteries where doing but as noted I'm returning them - the question now remains what to get and if my supplier can supply something they don't normally stock - will have to see SolarMDs 14.3kWh battery seems to at least according to their spec sheet have the most honest representation of what/how the battery will perform - and if I can make some modifications to my loads and not exceed 4kwh loads at any one time then I can follow their recommended 13kWh useable storage @0.3C or +-3.9Kw load I'll post back here what happens next...thanks.

lazy typo's on my part sorry yes I know its kWh...engineering OCD is welcome Update: now you triggered my OCD - updated posts to kWh for this thread as much as possible - thanks for contributing to my insomnia

Hi @HendrikBigChief here is hopefully what you need/asked for Whole 24hr for the day in question Battery voltage is 53.99-54.00 from 00h00 to 09:28:29 when I start the run down - rundown below At 7% Eksom feed is restored - next images are charging @40amps Finally from 22h00 to 23h59 is a loadshedding slot with my usual base load of 480-630watt TV, fridge, routers, fiber and a few devices in standby etc. that base load comes into play most days from about 20h30 and will reduce to about 340-480watt from 1am to 6.30am The latest firmware update (13/06/2023) from CFE eliminated the SOC cycling, prior to that the update the did changed SOC to cycle between 100-95% & before that it was 100-90% when the system was originally commissioned. Here is the 13/06/2023 data (last firmware update) you can see the batteries drop out at 12h48 this is when the firmware was updated the batteries where powered on/off twice. At 16h06 you can see the same catastrophic issue appear again after reaching 100% "SOC" at 13:55:53 until 16h06 when load shedding starts and at 18h01 an active load kicks in, @18:07 its hits 46% and @18h13 10% just as Eskom power is restored and at 21h13 100% SOC is achieved @ 53.49v The below is from Solarman, a steady SOC @ 100% for 6+hrs - it would appear that in data going back to commissioning date, float voltage has always been 53.88-5399 and now 54v after the latest update - charge voltages have always been maintained up to this last update at 56.1v I believe for LFP charging in parallel the parameter is normally 56-56.8v

Sure - I’m going to collect the data for you and I’ll post it up with what you suggested

Thanks @Tinbum the cable lengths are identical so it should then be as per fig 2 - very confusing the manuals vary and add or remove info for the same version battery 3-4 months apart

Thanks @HendrikBigChief I'm running in storage only no solar currently. Agreed. You keep referring to SOC (I beg to differ on the correct calculation thereof but anyway)- I'm referring to the actual usable Kw I'm getting out of the batteries in BMS or Voltage mode being 6kw at best for 10.24kWh of storage (the center of my gripe to begin with) 60% of my installed capacity after 7 months of frankly light use? - not acceptable! I've calculated multiple times with loads I know to be correct and constant and can monitor via other means and not just the battery app, inverter logging or DEYE Cloud/Solarman so that I can verify the data. I've experimented with this before "time of day usage" I have no solar so not really relevant - I can confirm that this has been tried before as a possible problem solving approach and made no difference - for example allow the batteries to go to 60% with solar but while being Grid tied do a final run up to 100% late to make sure you're topped up properly (I understand the rational )- my intention and detailed below is to be 100% of grid I will not be grid tied at all - but in a Storage solution only as i'm currently setup I don't have the luxury of entering say stage6 with 60% left at any time of the day, especially when the power doesn't come back on in some instances for another 1-3hrs I never said I was doing that as my normal operation - I suggested at the beginning of my thread people should got back and read my first post and the original one I referred to because it seems you've not done that other than insist multiple times now that BMS are bad and that I run my system in Voltage mode and thank you later. I won't be running in V mode - I did that previously only to confirm the data and for trouble shooting 2 weeks ago during the firmware updates to corelate data I had collected. Hmm...why would any manufacturer have a BMS that specifically is going to shorten the life of battery(s) that they have to warranty for 10yrs if that is going to as you're suggesting almost definitely lead to them failing prematurely? Why have a BMS at all then? See where I'm going with all this? There are numerous applications, devices and systems that have existed long before LiFePO4/LFP & prismatic cells and the like and those BMS systems have all worked correctly in my experiences - I have lithium battery based systems 10+ yrs old that still work to within 80-90% of spec... This all paints a very bad picture of batteries in SA at the moment and confirms my suspicions all along and as you've mentioned and rightly so that none are really suitable for the multiple loadshedding events we have - They are vastly exacerbated in a Storage only setup like mine. That a real issue for me and the type of Money myself and others are forking out. I've outlined previously but will touch on again the energy production route I'll be following: 8.1kw solar array (Still to be commissioned) - in ideal conditions, no clouds, no panel shading, ambient of between 25-35c etc. etc. I can comfortably produce 25-30units each day - an array this size can peak at 45+ units a day - I use a 4.8 hour factor to calculate possible peak and exclude the trailing in and out power that would be created from 7am-9am and 3pm-5pm which on a good day could account for another 8-12 units (over the conservative 25units) in my specific array - easily getting me over my worse case 20-25 units a day I need - so I've erred on the most conservative side possible. My battery storage is only meant to supplement poor production numbers between 9am and 4pm and at night 10pm onwards where my base load never exceeds 700w I have embedded diesel generation - 6.5kw and fuel for weeks Using my program logic which I've implemented before, I can run the Genset between 8am and 8pm at night that steps in to: Supplement load if the weather is kak, or if storage is below 40% or solar generation is below a threshold I set or all of them combined I can top up storage (batteries) if it is below 60% @4pm in winter and 5-6pm in summer (I can vary this window up to 8pm at night reasonably) In all these scenarios I'd most likely keep to my 40amp charge rate (which I've used) and well enough below the 0.5c recommended on most batteries if you want to actually take care of them. We'll agree to disagree on you not believing in running a BMS - as I've stated for me this is simply non negotiable and for LFP poses a significant system risk - insurance companies would have a field day with 60%+ of the installations and so called "professional" ones I've seen. The BMS is the heart of or the ticking time bomb in an LFP pack and it must 100% work - I'm non-negotiable on it. If I have to go through 10/20/30+ battery brands to find one that actually works according to spec - so be it - I'll burn diesel when they don't - simple. The manufactures data on all of these batteries (and I've studied 10 of dozens of them by now) are disingenuous at best to flat-out lies, hidden in small print where some bother to disclose it with others simply stating numbers that go against the laws of physics / science and in this case chemistry. I'll pick on SolarMDs 14.3kWh pack (which I am considering) the real number in their specs which is the only one worth reading is 13kWh usable at 0.3C - that's a measly 3.9kWh load (for me) and I'm pretty sure that if I ran that pack at 3.9kw that I would not get 3h33min of runtime - SolarMD i'm up for testing. Just like my CFE packs which can at best deliver 3kWh out of 5kWh @ supposedly 1C - they like to obfuscate the numbers and bullshit on their labels but these 5.12kWhw batteries can only deliver 0.5C semi-reliably which means you need to keep load at below 2.4kw to get anywhere near getting 3.5-4kWh of use out of a 5.12kWh pack - Naturally I've tested this and @ 1.7kWh load the battery discharge curve is fairly linear to about 30% then tappers more seriously as the packs voltage drops to 50-49v - I don't know about you but I didn't pay R55k to have 1.7kw on tap and their technical spec says I shouldn't have to accept that dreary performance either. More so i'f i'm going to expand to 20kWh or possibly look at 2x 12/15kWh packs I've seen numerous sites, heard advice given by resellers, installers and electricians alike (all self confessed "experts") that have for example said that 2 (or more) x 0.5c batteries means you now have a 1C system or 2C system (4 packs) etc.- this is categorically false - you have a larger storage pool but you're still governed buy the 0.5C rating. Bottom line - for the average consumer out there this discussion and many others like it wouldn't even vaguely resonate with them or allow them to know what to follow - or do - so they do what most consumers do - follow the guidelines in the specs or rather the specs the installer regurgitates off of the manufactures data. I'm calling out that specific data, in most cases, grossly misleading and at the very least contradictory.

@JAK I was of the same opinion but I’ve been staring at this nonsense over the last week for so long I wanted to see if I was missing something - thanks.

Also my reason to be apprehensive about doing this is that when you run them via the inverter in voltage monitoring mode the BESS app (which is mostly rubbish) cannot communicate with the battery at all (until you go back to BMS mode) and provide any battery details, no individual cell voltages, SOC, AMPS in or out - I actually think in this case the BMS is "asleep"...

@JAK do you agree though that the two manuals contradict one another in terms of parallel connection diagrams? Or am I just being paranoid?