Leondavibe

ok so the system isn't foccused on savings as load is run from eskom menu item 1 UTI, when solar is doing well can switch menu item 1 to SBU then load will be powered from solar to save more power and excess solar will charge battery, and then switch 1 to UTI after hours again if you want to keep battery rerserve for eskom outages, if you want to save as much on power as you can , you can then leave it on SBU for a portion of the night to empty batteries to accept more solar next day, but then the charging priority option SNU/CSO/SOL has to be on SOL ie only charge from solar, it will leave the bvattery where it is at when you switch back to UTI and apply no charging until solar kicks in next day SNU charge with Solar and eskom at the same time if you have chaging amps set to 30A and the solar produces 20A charging then the other 10A will come from eskom CSO will charge only with solar if available, once solar goes to zero it will charge further with eskom the problem is even if only 10w it sees it as charging from solar and eskom doesn't help, if you have a breaker on panels flipping it off will force eskom charge on this setting, or you have to set to SNU when you know shedding is coming SOL will only charge from solar and once solar is gone battery is left to settle wherever it is at and only start charging when solar is avialable again UTI load powered from eskom and SOLAR is left to charge battery only (unless youir inverter is hybrid and can mix eskom and solar most axpert types aren't) SBU load will be powered from Solar then battery and if it hits the switch back to grid voltage it will use eskom SOL on menu item 1 will only use Solar/battery and no eskom so you have to play with both the UTI/SBU/SOL and the SNU/CSO/SOL setting to find the mix you want

ok the fans ramp up based on solar output that is normal normaly the fans are quiet when the load is being powered from eskom and only ramps up when load is higher, their fan speed is also linked to solar output, so if the solar output goes up so does the fan speed, so nothing to worry about, when close to full the bms can sometimes stop charging as one of the cells peak and if the balancing drops voltage then it starts charging again hence kicking in and out the other possibility is if the charge voltage is a bit lower the inverter can switch to float mode prematurely, then as the voltage settles the voltage can drop below the float setting which triggers another charge session if you are sure the battery is full which will probaly be the case with the voltage you mentioned, and your battery maybe rests at a slightly lower voltage lowering the float voltage a bit to match its natural resting voltage you can get out of the constant triggering of charge cycles or maybe lift the charge voltage higher closer to the max if the battery cables are very thin or long it can also cause a voltage drop, so then the battery isn't really at full voltage and the inverter thinks it is, once it stops charging the voltage settles and it sees the battery isn't full and thus starts charging again normally in float mode the voltage isn't affected that much since the amps are very low, and thus it may get more accurate reading while floating and not while charging i would try the charge voltage closer to the 29.2 and see what it does, can then also set the load to be from eskom and set the float very low to allow the full battery to rest without triggering another charging cycle see what voltage it settles at then set your float to that voltage

the battery light flashing isn't abnormal as any charhing normally cause that i think ie float also counts as charhing so the battery is probably always charging or floating what do you mean it is coming on every few minutes some inverters have a powersave mode the inverter goes into standby if load is low enough and comes on if some load is detected could maybe be that menu item 29 is for that SdS is disabled and SEn is enabled what battery do you have gel or lithium, do you have solar and what is the voltage settings and charge priority menu items are 14 is battery type 17/18/19 is the charge/float/cut-off voltages 10 is charge source priority

normally there is two different settings regarding this the one deals with the priority of solar ie load or battery fisrt and then grid feed and then there is a different setting that determines the priority for load ie grid/solar/battery so you gottan check which menu item deals with it output source priority normaly it is something like UTI/SBU/SOL uti is eskom SBU will use solar and battery until the back to grid voltage is hit and then use eskom and SOL is solar only so not sure if it switch inverter off or switch to eskom if battery is flat don't use it and the other setting has charge sopurce priority

i see it the other way round ie the hybrid inverters you can set and forget and it will blend eskom and solar when battery hits x SOC you have set while the off-grid axpert types means you have to play around with switching UTI/SBU since only some can blend unless you have enough battery power to essentially go mostly of grid, which is often not the case ie those going for the cheaper axpert options tend to have lower battery capacity Solarassistant can help make it a set and forget, then it will command the inverter to switch back and forth as needed, solar assistant allows you to pull data from axpeert types into homeassistant and can also give commands on certain things to the inverter via solarassistant pi allowing remote management , and the data is realtime not the crap of 5min with sunsynk or other cloud setups if/when i buy a sunsynk i would still do the pi realtime data route

the battery will charge at the amps you specified in your charging settings, if the charge voltage is high enough then the moment the amps drop you know it is full, ie any charge voltage above 3.55v per cell x8= 28.4v for 25.6/24v battery you are good to say amp drop= full while a voltage under 3.5v per cell ie 3.45v may be hit with a high charging amps when battery is above 70% soc so then the amp drop means nothing most inverters have a charging algo that kinda goes like this , keep amps constant until it hits the charge voltage max that is the CC phase constant current then it will switch to CV and keep charging with whatever amps the battery takes without exceeding max voltage until the amps drops to x% of max charging amps ie normally 10% so it will maintain the max voltage until the charging amps drops below 2A ie10%of the 20A charge rate some have a time limit on the CV phase too ie it will stay in CV for lets say 30 min max so if the amps does not drop below 2A by then because the charge voltage was maybe too low to have the battery full by then it just stops charging hence why it is important to have a higher charge voltage of at least 28.4v most of the charging is based on if else type programming, and hence why some inverters can get stuck in a float voltage if panels are present and it charges over a long period of time, (axpert inverters has what is called a float bug) a person can get it out of the stuck position by momentarily lifting the float voltage i just left my float voltage the same as charge voltage then it doesn't happen, i don't want my battery to stay at that high float though so i just set my inverter to charge solar only x amount of time after dark and since no solar it just lets battery rest

yes with a nice high charging voltage ie 28.8 3.6v per cell, most charging will happen in the constant current mode and very little in the cv phase when the charging current drops low you know it has switched over from CC mode to CV mode and is basicaly full ie 99-100 % probably the moment you hit 28.8v you know the battery is full and if you did not use it at the settled voltage of 27v it is still full with a flat curve 70-99% soc can be very close to resting full voltage, hence why the reason why we say it is full when it hits 28.8v is because we know that it entered the steep section of the SOC graph ie the battery cannot hit this voltage if not full but if it settles to rest after being full then 27v is still full which baffles people 27v is full and 28.8v is full so which is it and then enters all these graphs trying to explain this sitting the pot miss most of the time especially since you can see a 0.5v voltage drop due to length of battery cable when under load and 0.5v makes a big difference hence why i say just ignore these graphs when it peaks it is full when it dips below 3v close to empty anywhere in between you are fooling yourself can get a rule of thumb based on your own system ie if you see your system hang at x maybe 26v voltage most of the time and the moment it drops below 25v not long before you get low warnings then you know ok that is you signals even the bms that coulomb counts can lose a bit and drift ie 1-3% in a cycle ie it can't count what is lost due to battery losses ie as heat in bus bars and as balancing losses, it only counts what flows through it

yea the graph is bogus there is no way the battery will be at 3.21v per cell ie 26.12v at 10% soc and fully charged no way you will see battery full while charging with a voltage of 26.92v yes if you keep it at that voltage after charging forever it may end being full a lifepo4 battery 25.6v 8S(8 cells in series) ie to be certain the battery is full you need to hit 3.55-3.6v per cell to be sure it is full ie 28.8v, the same full battery will settle once charging has stopped to 27v if the float settings allow it thus 28.8v is full and 27v too just under different conditions

Most of the problems related to SBU voltages Are related to lifepo4 batteries having a rather flat charge/discharge curve ie you experience either one of the the two Set voltage low and have more savings from solar but bump up against low voltage shutdowns (in sedding) Or Set voltage higher and inverter will switch back to grid way to soon limiting solar savings The best solution to this off-grid axpert inverters Is a cheap raspberry pi With either solarassistant/SMH That actually uses math to determine the state of charge ignoring voltage And uses that to determine the switch to grid or battery Making keeping a reserve for shedding easier Can also do remote management in case the weather changes or shedding stage changes It really is a game changer I have a few profiles set to intervene remotely

Yea if you make the float voltage higher then the chances of losing solar production is less I just change the profile for charging to be only solar and thus the batteries won't be kept high float for long as solar dies down it won't float from utility

Using a chart like this on lifepo4 is folly it is almost impossible to determine SOC from voltage if the battery isn't at either side of the flat voltage curve, ie when it hits the spike up at the top when full or the knee at the bottom when basically empty People try to recreate a chart , that worked on batteries with steep discharge curves for a lifepo4 it is a joke If you hit full voltage it is normal for the amps to drop, the charger will charge max amps until voltage is hit then Limit the voltage and charge slower rate until the charge amps drops to a certain % of charge rate the y is garded as full and switches to float mode Some inverters on USE/Li settings doesn't apply a float voltage it use the float voltage as a trigger only My one inverter works like this, it will charge , change to float mode ie apply no voltage and let the battery come to a rest voltage and once the voltage drops x amount under set float voltage it would trigger a charge cycle again, so setting a high float would see that inverter charge leave battery to settle to rest voltage once it triggers it would charge again Setting the float lower allowed the battery to rest until next shedding (battery backup only had no panels at the time) Instead of repeating this loop The charts are useless Resting/float approx 26.8v is full ie My system is 48v i will charge to 53.9v and my battery will come to rest at about 50.5 The voltage can shift a bit if moving from charge/discharge/charge again Both those voltages are full All you explain sounds normal for a lifepo4 battery So as an example look at battery soc chart when resting full voltage, then simulate shedding switch of mains look at chart, then switch power back on look at chart again compare voltages Now did your battery truly discharge 20% and charge 20% in a blink of an eye, probably not, that should highlight how much a joke the charts is

Yea but using the voltage is crappy with lifepo4 flat curve ie you can't get a nice voltage to have the reserve consistent ie voltage sag may mean you have a bigger reserve on high load or low load means you have a smaller reserve I could get solar assistant to talk to the shoto via rs485 but the could not get the soc to display correct Bought a usb-rs485 The soc was only accurate when using the connection via the rs232 port ie phone plug to the left of rs485 had a rs232-usb adapter already that i used with pc The protocol selected as it was on solar assistant website I tried solar assistant via trial Have been using SMH for a while, used the emulated bms so it calculates the soc with the stats load etc as i have mixed batteries one shoto and one diy battery have not gotten around to get both set up for coms Using one of these 2 smh/solar assistant connected to your axpert via a raspberry pi,Makes managing the device something you can do remotely So you can see the the soc and then change the sbu/uti if weather or shedding changes It really is a game changer with these off grid inverters as you can't blend eskom and solar You can use eskom to carry load and solar gets relegated to battery charging, easy enough if you arenin front of device, but if not home you essentially have to wait until it knocks on the back to grid setting Setting it too high means you lose lots of solar production , too low next to no reserve for shedding Thats where the remote management changes the game

leaving this here in case someone else stumbles onto it is it the right way probably not , just what i had to do to get it working to have the stats so i can use it in automations their advice was connect to the node red implementation running on the pi ie X.X.X.X:1880 from a different pc or from the smh pi itself localhost:1880/127.0.0.1:1880 then follow the how to configure directions # How to configiure: 1. Doubleclick the Output to Home Assistant Icon (Node). 2. Edit the properties of the MQTT server (click the pen icon). 3. Enter the IP address for your home assistant server. 4. Click on the security tab and enter your username and password for Home Assistant 5. Click Update once done, and then Done. 6. Click the Deploy Icon (top right of the screen) to enable SMH to start posting to Home Assistnat 7. DONE! if it works for you great this did not work for me , well it did, it connected but home assistant did not auto discover anything when i connected with mqtt explorer , i could see the birth message i told it to send nothing else so then i just used the pi's mqtt broker since i noticed it has an mqtt broker running so i configured thome assistant to point to the ip address of the SMH pi and then i looked at the topics i found while connected with mqtt explorer and just configured the sensors manually in home assistant by popping this into the configuration.yaml of my home assistant the name you can call whatever works easier for you, having the inverter in the front just had them all grouped together in the list of sensors naturally just check the config files before restarting home assistant that some or other error does not make it non bootable i just added all i found might trim down if i find some don't work or aren't used this isn't all the telemetry of the inverter this is telemetry from SMH which get them from inverter hence some of the items you could see via the likes of solar assistant is missing as it creates a mqtt broker that forwards every single item and makes it easy to change the settings of inverter too have not progressed to the point that i can change anything via mqtt/home assistant, total noob when it comes to home assistant and mqtt i assume cluster will have multiple entries if you have more than one inverter i have 1 axpert so no idea what it will look like if multiple , and then inverter values will show total while the cluster topic will show individual stats may then have to edit the yaml with whatever you need i just added all except the ones that would essentially be duplicates stats mqtt: sensor: # invertervalues - name: "Inverter_Load_percentage" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.load_percentage }}" - name: "Inverter_Load_Watts" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.load_watts }}" - name: "Inverter_PV_watts" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.pv_watts }}" - name: "Inverter_Mode" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.mode }}" - name: "Inverter_Grid_on" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_on }}" - name: "Inverter_Grid_watts" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_watts }}" - name: "Inverter_Grid_frequency" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_frequency }}" - name: "Inverter_Grid_voltage" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_voltage }}" - name: "Inverter_Grid_amps" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_amps }}" - name: "Inverter_Volts" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.inverter_volts }}" - name: "Inverter_Amps" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.inverter_amps }}" - name: "Inverter_Frequency" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.inverter_frequency }}" - name: "Inverter_Temp" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.inverter_temp }}" - name: "Inverter_total_load_watts" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.inverter_total_load_watts }}" - name: "Inverter_pv_kwh_produced" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.pv_kwh_produced }}" - name: "Inverter_efficiency" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.efficiency }}" - name: "Inverter_Total_kwh_used" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.total_kwh_used }}" - name: "Inverter_avg_pv_volts" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.avg_pv_volts }}" - name: "Inverter_avg_pv_amps" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.avg_pv_amps }}" - name: "Inverter_max_load_day" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.max_load_day }}" - name: "Inverter_max_load_hour" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.max_load_hour }}" - name: "Inverter_max_pv_day" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.max_pv_day }}" - name: "Inverter_max_pv_hour" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.max_pv_hour }}" - name: "Inverter_grid_kwh_used" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_kwh_used }}" - name: "Inverter_grid_kwh_import" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_kwh_import }}" - name: "Inverter_grid_kwh_export" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.grid_kwh_export }}" - name: "Inverter_solar_battery_watts" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.solar_battery_watts }}" - name: "Inverter_solar_battery_kwh_used" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.solar_battery_kwh_used }}" - name: "Inverter_fault_msg" state_topic: "Open/Inverter/InverterValues" value_template: "{{ value_json.fault_msg }}" # Cluster - name: "Inverter_pv_volts" state_topic: "Open/Inverter/Cluster" value_template: "{{ value_json.pv_volts }}" - name: "Inverter_pv_amps" state_topic: "Open/Inverter/Cluster" value_template: "{{ value_json.pv_amps }}" - name: "Inverter_serial_no" state_topic: "Open/Inverter/Cluster" value_template: "{{ value_json.serial_no }}" - name: "Inverter_firmware" state_topic: "Open/Inverter/Cluster" value_template: "{{ value_json.firmware }}" # battery - name: "Battery_Capacity" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.stack_ah }}" - name: "Battery_soc" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.soc }}" - name: "Battery_Time_to_5" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.tt0 }}" - name: "Battery_Time_to_full" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.tt100 }}" - name: "Battery_batterywatts" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.batterywatts }}" - name: "Battery_batteryvolts" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.batteryvolts }}" - name: "Battery_batteryamps" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.batteryamps }}" - name: "Battery_batteryamps_used" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.batteryamps_used }}" - name: "Battery_battery_mid_point" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.battery_mid_point }}" - name: "Battery_max_charge_day" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.max_charge_day }}" - name: "Battery_max_discharge_day" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.max_discharge_day }}" - name: "Battery_daily_charge_kwh" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.daily_charge_kwh }}" - name: "Battery_daily_discharge_kwh" state_topic: "Open/Battery/StackTotals" value_template: "{{ value_json.daily_discharge_kwh }}"

Adding for posterity The kodak and other axperts can switch to bypass mode when you exceed the inverter output ie you pull more than The inverter can handle and if bypass on overload is enabled then the axperts switches all the load to eskom and pv is relegated to charging batteries only When the load drops it switches back to battery mode If however you exceed the limit and load shedding kicks in then the load goes back to inverter and promptly trips the inverter If you have restart on overload enabled the inverter will restart and power the load if you have switched of enough devices to be under the inverter output

Since you have active balancers , you don't need to buy a power supply Whenever you are home while battery is fully charged just lift the float voltage to sustain the voltage at 3.65v per cell and switch on the active balancer When load shedding switch it off Then when fully charged switch on the active balancers again Just don't leave them on all the time As they may move power around in the flat portion incorrectly ie do work it has to reverse again when full All you want is to be balanced at 3.65v ie all cells has to be 3.65v at the same time

Because you always have cells that differ so you will always have runners So even if lucky that you don:t have runners at the top ,ie that you have enough cells that peak at the same time to hit pack voltage before single voltage overvoltage You balance because you want to prevent runners at the bottom that will lead to faster degradation of certain cells which limits packs capacity

You also get one that has a bluetooth app and can enable and disable balance function and if i recall correctly can also set the voltage where balance should start and the balance current Uses same app as jk bms https://www.aliexpress.com/item/1005004322793283.html?pdp_npi=2%40dis!ZAR!ZAR1%2C705.72!ZAR1%2C193.99!!!!!%402103010b16919576739048116eb60b!12000031119255677!btf&_t=pvid:da821a89-9a3b-4f54-a86b-d5795aeeaeae&spm=a2g0n.ppclist.product.0

Some of these active balancers have place for a switch and it is just shorted on the board Putting a switch on it and leave the active balancer inside the battery and just have a switch to enable active balancer from time to time when in the steep section of the soc graph not all the time I have a shoto server rack battery with one bad cell that always drifts I soldered two wires to this cell routed through a hole to the outside of my case to a quick connector When this cell has drifted i manipulate this cell by connecting a charger to this quick connector or add resistance if i overshoot the charge

The flashing run light is the only one that allways works when battery is on The soc indicators only light up while charging or discharging The reset button if held for certain amount of time can act as a power button Then lights left to right on power up And right to left when power down Holding it longer does a reset/reboot

So could also check the load and pv production on each inverter to see if the hypothesis is right/wrong If it is either restructure the load by moving load from the one where loads exceed the panels to the under utilised one or restructure the solar panels so that more panels are connected to the inverter that carries more load ie if one inverter carries 50% of the load it should get 50% of the panels If it isn't at its max yet But yea until you have a setup with an acceptable ballance it will feel like whackamole

Only things i can think is The panels are divided over 3 inverters ie 3phases Each inverter can only feed it's panels to said phase ie lets say pv phase 1 4kw Phase 2 3kw Phase 3 3kw So if load is 5kw on phase1 And 4.5kw on phase 2 It would have to assist from grid on those phases The 3 phases are 3 seperate rails solar from the one rail can't reach the other rails The last phases output goes to waste if no load on that phase Unless if you set the items to work only from batteries to then refill batteries when load is less Or if batteries are pooled and thus if the items are set to only use batteries the last phase can push into batteries and the first two phases can assist from the batteries pulling the power the last phase is pushing into the batteries

I assume by now you have this running smoothly What is the costs involved for subscription And for the initial setup, i assume you have the be logged in, what is the defaults ?

Comunication is important if you want to know how much you have left in the tank imo You can operate a battery in dumb node as some say though that is a misreprestation imo As the bms is still managing the battery ,to prevent any damage The only benefit of coms is that you can then force a shutdown on a certain SOC And know how much you have left in the tank , though many batteries have a light system to indicate 25/50/70/100% so in dumb mode you would just rely on that Imo the coms is overhyped When it comes to loadshedding it can make a difference when you have panels ie if it is only a battery backup dumb mode works perfectly fine If you have panels and the battery is in play, ie it will use that with panels to meet load , and you want to stop using oower at a certain point to leave a reserve tank for load shedding then an inverter that can use the soc to switch to eskom can make a difference But as far as i have it many use a voltage setting for this , the sunsynk can use soc % , so if the inverter cannot use the soc% and rather uses voltage there would be no real benefit to coms imo

the pylontech is 0.5c charge so if both inverters were pushing max amps the 183amps would exceed the 150A you can push into 3 batteries and naturally if one is full before the others due to cable lengths differences even more so ie lets say you aren't pushing more than the 150a so lets say you charge 110a combined and the one battery is full it stops taking charge as bms disconnects cell from the charge , now the 110a is divided over 2 exceeding their charge limit protection mode can be hit, if the charging was on full tilt

If you don't have a charger to do the top balance You could help the balance process by adding a load to the cells that are high pulling it down allowing it to charge a bit more on low cells next time rinse repeat untill all cells eventually charge full But after doing this (on a battery with 15cells) I have to say the easiest way is to get a buck converter for R100 or so ,set it on 3.6v And connect it to the low cell when the battery is fully charged according to the inverter , and then charge the low cells to 3.6v one at a time ie this doesn't have to happen in one stint ie you can let the inverter charge the battery full stop charging, then charge the lowest cell full if not full ie hitting 3.6v before load shedding hits , you just carry on on this cell after the next charge session ie wait for inverter to stop charging, then connect to the same cell until you hit 3.6v Then load shed After next charge session add the buck converter to the next lowest voktage cell Rinse repeat until all cells have hit 3.6v while battery is regarded as full by the inverter Very few bms's have a active balancer , most have passive with pathetic balance currents So my gut call is just let go of the fairytale that the balancer will sort it out over time In fact it will add wear and tear on the low cells that will. Impact the caoacity of the combined battery if not sorted