WannabeSolarSparky

Interesting discussion about the "Rules"

Stick with reputable known good suppliers. https://powerforum-store.co.za https://www.diygeek.co.za My 2x Narada batteries and and 1st growatt spf5000es and Sunsynk 5k inverter came from DIYGEEK running more than 5 years now with zero issues https://segensolar.co.za Need an installer account to buy, some bargains but mostly a bit pricey https://www.solarwaysuppliers.co.za I buy my panels and mounting systems from them, best prices online open to public https://acdc.co.za Expensive, but can go there in emergency if desperate for something. https://www.liteglo.co.za Electrical supplies online - nationwide delivery quick and their prices are really good, they based in JHB and I am in Cpt often get supplies from them cheaper than suppliers in cape town even after adding their courier fees.

Yes, that is to mitigate the back-feed when high loads switch off (mostly the geyser) and to have the benefit of the extra amps if I ever need to startup big loads. I tried zero and 20watts before but ended up over-running by 100 to 200 watts back to the grid for split second. The sweet spot for my setup seems to be 50watts. Goal is to give Eskom as little of my power as possible. This will all only change when I am ready to try fully off-grid again or when I am "forced" by Eskom to go that route. No, All my loads are on the grid side with only my home-lab server on the Essentials side. When/if the grid goes down then all the loads are automatically switched to the essentials side.

I hope and trust that you will all have a great prosperous and sunny 2026 😀 After quite a few years running solar, my system is finally getting to the point where everything is running optimally. Eskom only got R115 from me in December and in my books that is almost a big win :) This year I have planned and budgeted to add another 10 solar panels to get ready for winter and to add my 4th JK powered battery to the system. Winter 2025 showed me that I am way short of charging power and ended up where I had to give Eskom R400+ for 2 months (June/July) to top up my batteries. I have north facing roof space to add the 8 new panels, so this should hopefully be enough to keep the batteries topped up nicely through June/July. The added bonus of the new additions will be when Eskom start implementing fixed fees, I should then be able to disconnect and go fully off-grid. For all the HA users here as some really nice animated sensor cards and switches. https://github.com/Anashost/HA-Animated-cards

Usually with lithium batteries you would check the individual cells voltages, you will quickly notice/see a cell or cells that have problems as the will usually be a few milli-volts away from the average. Good healthy cells in a battery pack should never be more than 0.005 volts away from the average. if they are then it could indicate a bad cell or improperly balanced cell. You say 3 - 4 years, by that time I think other chemistries may or may not be available that may work differently.

That is quite normal, the voltages of each battery will never be the same due to various factors (age, cell resistances, connections, cables etc etc). However if there is a very big difference then interrogate the batteries more closely to ensure all the cells are in good health and that your balancing is working correctly.

A many of you know already I love data, but sometimes it can be a pain to get data streaming in reliably. There are so many different ways to do it. ESP32 with rs485 ttl, Bluetooth, arduino ttl/rs485, rs232 etc etc the list goes on. Many are very technical and need an understanding of how to program esp devices. I have now found what I think is the simplest way to connect your JKBMS batteries to home assistant. The data flows in very reliably at a decent rate (Almost realtime) and all you need is a simple rs485-usb adapter and the ability to follow some simple step. Data flows nicely into mqtt and exposes a crapton of data entities for you to use all over your HA where ever you like. You can make adjustments to the bms settings right from inside HA And if you too lazy or time constrained then you can get a ready done for you templates to get you going You can view this project on github (Yes it's open-sourced) https://github.com/jean-luc1203/jkbms-rs485-addon

I upgraded my 2 naradas from 15 cell to 16 cell and replaced the narada bms with these https://lithium-cells.co.za/detail/429365 I also upgraded 2 Sunpays 15 cell to 16 cell and replaced the pacebms with these https://lithium-cells.co.za/detail/429365

2022-JK-BMS.pdf

those images you shared show the batteries at midpoint in the flat area of the charge cycles, you will not easily see bad cells that way, you should rather check at the top end of a charge cycle to try pinpoint bad cells. and check each cells voltage to see/find runaway cells.

sounds like some of the cells may be out of balance. those batteries mostly use pace bmses so try getting the pacebms software and check the settings, they may need adjusting to help you bring all the cells back in to a balanced state.

giving unlimited cycles, and assuming normal usage, what would the remaining usable capacity be at the end of year 10?

JKbms's in my opinion are the best and will communicate nicely with each other and your inverter. And they have a great app to manage them and set all the correct settings. They also integrate very well with homeassistant and as @Scorp007 already mentioned, definitely go look at Andy's youtube channel. and definitely as @Sidewinder mentions, try making them into 16s batteries, worth the effort, i did that to all my batteries and they work way better now :)

@DieLem and they come with the required screws so no need to get those extra :) And those hooks are top quality, not like the knock-offs you see being sold everywhere at higher prices.