Missing link

Hi all - yes click-bait like topic for good reason.
Before I decided to write this particular post I also scoured this forum and noted that various users are having quite frankly unacceptable levels of SOC issues with all kinds of batteries even Pylontech and other "reputable" brands - so I'm starting to think that the majority (i.e. not all but 50-60%+) of the batteries and new makes and models that seem to land on our shores every other day, are simply not suitable for our unfortunate and insidiously unique power problems here in SA - I'm talking about frequent loadshedding, multiple times per day for 2-6 hours at a time, depending on where you are fortunate or unfortunate to be in our country.
Those that would like to follow previous long CFE discussions can view them  here  and I have a very long (sorry) but complete view of my installation, how I use it and the dreaded SOC drop from 40%-10% in 5 minutes or less or worse still 40% to 0% almost instantly here
For those that don't to go read them, a very summarised version is bullet pointed below which doesn't give you 100% context - so if you're going to ask questions or tell me I'm 'stupid' without referencing important info in the original post(s) - be warned - I'm called the TheMafiaMan for a reason...🤣
8kw DEYE inverter 2x CFE 5100s batteries setup as 30% restart 20% battery warning and 10-15% Shutdown. Final Battery setup will be 20kWh of storage via 2 more 5.12kWh batteries to be added in 2023 still. The system is protected by 200amp keto fuses and each board has surge protection as well - the house sits behind the inverter because A) I want clean pure sinewave power to all my plugs, lights and screens and B) fridges and appliances with inverter type motors are all better protected that way too. Your electronics will thank you. I charge the batteries @40amps so roughly 2kWh have experimented with 20amps and even 75amps - for my use case for now 40amps is my sweet spot giving my inverter head room to still run other higher draw loads when the batteries are charging. No solar currently, only used as a storage system to facilitate work from home and a "normal" quality of life (8.1kWh solar array is being commissioned) 6kva diesel Genset (dedicated generator room for Genset and fuel - already wired in with manual change over) just finishing off sound isolation, ventilation and then will automate change over with the dry contact and Gen feed-in on the DEYE Inverter Finally Eskom connection will capped off once solar is in and run in my own "Islanding" setup where I am my own "Utility provider". Let me start by pointing out that my supplier for all my equipment mentioned is Solar Advice - solar.co.za and that they have been only helpful, support providing and quick to execute where CFE keep dropping the ball - silver lining they will be sorting out my problem without fanfare - the way a reputable business should and I keep recommending them over and over.
From my side I agreed to go through not one but 2 firmware updates with the "overseas - team" at CFE, resulting in about 75% of my frustrating 2+ weeks of irritability.
Let's get on with it - two plus weeks of frustration, hair pulling and plenty, and I do mean plenty of potty mouth later - I now have the latest CFE-5100s firmware on both of my batters and the great news is...
I am at least 50% worse off than before, cannot make it through 2hrs of loadshedding with 10.24kWh of storage and less than 2kWh load, and those that are good at math that means? Yup 79-80% and then 3% 3-5min later, and then off. Unacceptable by any standards - I mean are there a few AAA batteries inside my two 5.12kWh LiFePo4 units.....???
But this doesn't really paint the whole picture so let’s start in Nov 2022
November 2022 system is commissioned and installed. Batteries are charged from +-56% to full over about 3hrs at 30amps or roughly 1.67kWh - for the Mathematically/Electrically inclined, 1602watt to be precise - DC wattage and AC wattage are not 1:1 parity 30amps at 53.4v is 1602watt - I was not charging my batteries at 6.6kw - if you think that, then this thread is not for you! load$hitting had not hit its full stage 6 stride at that time, so think mixes of stage 2/3, 4 and 6. Batteries were being used and run down to about 80-85% in stage 2 over 2 hours with mixed loads ranging from 1-2.5KWh and 55-60% in stage 4 or 6. We had no interruptions and not a single error or problems. We had a 12hrs long load$hitting event twice in the Dec/January and batteries hit 41% with a very OCD (me)controlled 350-450w/h load on these specific occasions – again no problems. Then we got into full stage 6 load$hitting 3 times a day - yep, I live in an area where we got 9-12hrs per day, day after day. Finally but irrelevant to the SOC issue like many other CFE and Raytech battery owners I had the 100%-90% cycle which I didn’t particularly have a problem with – go read the long post I made, to understand why – batteries should not sit at 100% for hours and days on end – I hope you have a fire extinguisher near – more info about that in my long ramble as well – go read it! This is when the problem reared itself for the first time between 40-38% left in the tanks and the inverter would either throw anything from a F56DC_VoltLow_Fault usually followed by but no exclusively F58BMS_Communuication_fault to even one or two F59AC_V_GridCurr_High Fault – for this discussion the most frequent by an overwhelming margin is the F56DC_VoltLow_Fault just as or about when the system hits 11/5% or 3% whichever the Chinese battery lotto gods deemed fit that day and then off.
The First update which required the inter-battery comm cable to be disconnected - took less than 3 min OTA (over the air) – each battery has a WiFi Module and independent battery monitoring software that can only seem to report voltage correctly as confirmed with a Voltmeter - but is useless at doing anything else.
I was instructed to cycle the batteries a few times between 10/15% and 100% and Monitor it.
The looping 100-90% discharge had changed to a 100-95% loop but again refer to my first long post (yes this current one will probably become known as the longest waffle on this forum – hopefully I’m a little entertaining at the very least) I still didn’t take issue with that.
1 week later the batteries now don’t cut out at 40% but now “gracefully” (intended sarcasm) go from 80-60% in 3min flat, then on to 50% at a leisurely pace and then when they hit 43% descend rapidly form there to 30/20/10/5/3% and then dead in 5-10min.
CFE stop responding in our happy little WhatsApp group containing expletives of me telling them everything from "they don’t know anything about BMS implementation, firmware and code writing" to how generally useless they are in responding to real issues – this goes on for the rest of the week.
They then announce how sorry they are ("Sorry Dear"??? I'm not anyone's darling/dear), that there WhatsApp wasn’t allowing them to log back in but that they had triumphantly a “new” firmware that would sort out all my trouble 😊
Disconnect comm between the two batteries again, never hear form them for another day but during the early evening get plunged into darkness because the batteries are flat and now to add to my annoyance charge from 0-100% in 45min going form 40-80% in 5min because can you guess why? They’re completely unbalanced – remember the inter-battery comm cable is disconnected waiting for the firmware update that never happened, and I now spend the next 2 days manually discharging each battery – via voltage control not BMS (by now it should be apparent to you that the BMS is $hit) and then charging each one individually, paralleling them again and reconnecting comms etc.
Firmware the 2nd finally happened on Tuesday this week – remember the one that will solve all my trouble😊 – batteries turn off after a successful OTA - Firmware update complete.
100-95% cycle now replaced by 100% and no cycling – hmm not too happy about that but I have other things to do, like work… and then Load$hitting that night 6pm - and 18min later plunged into darkness – 100% to flat - yes my troubles are truly over!
By now some of you probably have an idea as to what is the root cause of at least one of the problems – their BMS is beyond $hit – how do I know? Read on…
With torch in mouth while hurling profanity (I am quite talented you can tell) I disconnect everything to a safe point, reconnect only the master battery i.e., 1 of them and start everything up – switch to voltage monitoring mode to bypass the BM$hit (see what I did there) and apply a 4.2kWh load which runs for a whole 50min before the battery enters a fault mode and the solenoid disconnect trips – Thank god that actually works. Inverter shows voltage dropped below 47.9 (my own setting) and therefore the battery is at 5% or less.
Wash, Rinse, repeat – do the same with battery 2, the slave – and run for about 70min with a mix of 2/3.5 and 1.1-kWh loads during that time and then click - solenoid disconnect trips at 47.8v.
This all after the BM$hit declared that they where both flat to my poor DEYE inverter almost 2hours prior. By now I'm sure the inverter has developed or is developing schizophrenia.
Luckily by this time the power is back on and both batteries are at 1-2% each so I reconnect, re-parallel the batteries and connect the inter-battery comms and let the unit charge up in BMS mode (shocked I'm using the BMS again? There is a method to my madness) @40amp so 2.01kWh and monitor.
3hrs later we’re at 61% - great that is more or less correct, but then it all goes to $hit once again as 61-83% happens in about 10min and then 83-100% took 45min further – confirming my “rubbish BMShit” hypothesis in both directions conclusively. I did this 2 more times in both directions to confirm. Confirmed – in case you’re wondering - exactly repeatable.
I worked out on some spreadsheet – because I have time to kill like that – TheMafiaMan remember. At best, I can get about 6.5 maybe 7kWh of usable power out of my 10.24kWh storage but not without a massive, probably warranty voiding and time consuming workaround as you've seen above. Sorry, not good enough – I allow for 10% DoD as per the manufactures spec or maybe that should be claims. I paid like many people, a lot of money for storage, one of if not the most expensive single components in your system and I will not accept 60-70% and of that completely unreliable capacity – neither should anyone.
Anyone who has read this far – congratulations – but you must also by now agree, enough and no more. Which is exactly what I communicated to SolarAdvice – who have been privy to my WhatsApp “consult” with CFE and agree that I’ve exhausted all options.
I have options that I will be exercising and that is getting rid of CFE off my property once and for all – but this is basically a warning to all and sundry.
STAY AWAY from the CFE product – A properly working, reliable and trustworthy BMS in a LiPo, LiFePo4 and the like is non-negotiable.
You shouldn’t have to wonder if you can make it through 2hrs of loadshedding because the data you get from one of the most expensive items in your alternative power solution is “wonky” at best.
Unless you like dancing with fire – literally - and have a few chemical fire extinguishers on hand – you should have at least one with any large Lithium-xxxx-insert-your-particular-battery-chemistry-here anyway, but right now – for me, these represent a substantial electrical and fire risk to my property and the vehicles in my garage. I’m 100% not prepared to roll the dice on either side. Besides the fact that if you’ve followed my rant this far (thank you) this is not a workable use case and why I’ve had to postpone the Solar Array until I have reliably working storage solution.
As my intro eluded, this seems to be a far wider reaching issue cropping up on other battery systems too – so like others I’m left wondering what my options for a reliable battery brand are. One that can provide a battery system suitable for the SA market with our unfortunately unique power situation that actually works…
My Short list so far is 10-15kWh, 1C discharge rate and 10yr warranty
SolarMD’s 14.3kWh battery. Freedom Won 15/12 battery -  but not so sure I'm onboard with Local-is-lekker - Solar MD are supposedly also local but I know of a couple of installations    with both brands that are more than 12-18 months old and have had zero issues with the batteries, so I'll need to investigate some more -  there is at  least one horror story which seems like a 5 year old model with 470+ cycles that is basically dead and FW cannot offer replacement cells because they're EOL(end of life) according to the comment placed this guy purchased 5 x 30/24 units which he must have sold organs for    LG Chemistry – I don’t believe I will be able to source or afford it – at the moment rated worldwide as one of if not the best, but a 16kWh unit is almost the cost of a Tesla Powerwall think €9,377.00 sourced international with shipping and then add what ever bend-over-tax when it gets to SA and I'll most likely be at R220-240k+ and that’s without the Tesla’s already built-in inverter. You also need an installer with LG Chem Installer Certification and I've only found the 6.5kWhunit locally but no pricing from SegenSolar who to date have not responded to email or phone calls - I might try again. DEYE – I’m hearing good things, but they are also expensive – R38k-R43k for 6.14kWh (R6.1-7k per 1kw vs R5.2k I paid) - in Fairness if you pair it with a DEYE inverter they extend your inverter warranty to 10 yrs from 5yrs to match the 10yr battery warranty,  in essence you're paying for the 5yr extra warranty on your inverter so this is looking like an option but only if I can get a higher capacity single module between 10-15kWh will I consider this Sunsynk which is DEYE vice versa have a 15.97 LFP wall mount unit for about R96k so that is priced in my opinion more inline but I'm not sure if you get the same inverter warranty extension for a DEYE inverter because you do get an extra 5yrs on the Sunsynk invert... I’m not really interested in Hubble for personal reasons (but feel free to change my mind - also in the same boat with local is lekker - but I see that actual capacity seems to be questionable), anything with ESS in the name – I think CFE and few others are all the same 5.12kWh battery in fact wrongly or rightly so they’re unheard of in Europe, the US and Australia, both large markets for Batteries, which aren’t accepting inferior LiFePo4 and the like batteries onto their shores and we should be asking ourselves why.
The Only exception here is AlphaESS which SolarAdvice use to carry but no longer do and in hindsight while I was told the systems cannot be paralled to each other the 5kWh/10kWh Storage & Inverter Combo Smile5, is well documented and supported in Australia, Singapore and in some parts of Europe and the paralleling issue can easily be worked around by creating separate 5kW circuits and running separate subsystems - if I had to do it all over again which I cannot afford to do now, I would go this route because I have an honest Sparky and that means I would have split my solar array into 4x 2.025kw Arrays (2xMPPT per inverter) feeding 2 separate 5kw circuits with 20kWh of storage between the two and cost wise, would have come out about the same as my 8kw Inv. 20kWh(eventually) storage and 8.1kw Solar Array - However, I wouldn't attempt this type of setup with the majority of unscrupulous 'electricians/installers' I have had the displeasure of dealing with over the years.
Rant over - For now...
 
 
 

Guys ever thaught of using 4x12vdc fans in series then it will run straight from the battery pack(⁠•⁠‿⁠•⁠)