Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on [email protected] for help. Thanks :)
Hello All, This is just a friendly reminder to read the Forum Charter where you wish to post before posting in it. :)

Solis Hybrid inverter with DIY battery

2»

Comments

  • Registered Users Posts: 791 ✭✭✭ reklamos


    Check or ask if you can use 14s configuration. Also verify that it can charge cells to higher voltage as none of using 18650 cell. I do not think it should be a problem but the firmware might restrict that. Pylontech protocol is not a show stopper as it does work with diferent protocol.



  • Registered Users Posts: 108 ✭✭ meelick


    Ah Ok. I had ordered the one with 14S and 3.7 nominal cell instead of 3.2 nominal for LFP. I'll read up on that thread first before committing, see what the issues are.



  • Registered Users Posts: 108 ✭✭ meelick


    So, phenomenal progress this evening. I got my wee UART to CAN bus adapter, (about £5 on amazon), and I had a few ESP32 boards lying around. So I used the git repo in the second post on this thread and built a variant of what's in the repo diagrams, no display, no digital isolator (that the impatience in me). A few hours to get the sketch to compile, there's a particular version of the Daly UART lib that's needed. Guru Meditations (crashes) all over the place, but now I'm finally getting places.

    This is with the battery set to User Defined, and it's successfully reading the SoC of the BMS though the CAN bus interface and displaying it on the inverter! It's also showing "CAN OK".

    It's not doing much else at this stage, but I think this is a huge milestone for me, and I think I'm on the right road to getting my battery working with the Solis inverter, finally. :)



  • Registered Users Posts: 3,302 ✭✭✭ graememk


    Try the aobo battery setting. That's what the rest of us is using



  • Registered Users Posts: 108 ✭✭ meelick



    At this stage I've got my canbus bridge emulating user-defined, aobo (using SMA protocol), and Pylontech (I did the changes to give the correct name and the metrics in the right places according to the pylontech doc above), and I'm still not getting current pulled from the battery. I've verified the battery with a resistive load and can easy pull 10A from the BMS, app shows info fine. Just not working with the Solis no matter what I try.



  • Advertisement
  • Registered Users Posts: 108 ✭✭ meelick


    Got it working. I'm not entirely sure what changes I made to the ESP32 sketch, but I'll analyse that over the coming days. I'm using User Defined, and Inverter now starts charging when SoC is <80%, and discharging when the load requires grid pull, at which time the battery kicks in after a few seconds and supplements the solar (if any). Here's a pic with a 2kW heater, causing draw from the battery.

    And a pic of the battery info screen:

    The sketch is using v1.0 of the daly uart library, the latest version uses significantly different API, and would not build. I haven't got the MQTT side working yet, but will do soon. And I might update the sketch to the latest daly uart lib api, as it might be able to pull more info from the BMS.

    I like the fact that User Defined works, as I can tweak the voltages to suit my 14S100P Li-ion setup.

    Thanks to everyone on this thread that helped!



  • Registered Users Posts: 108 ✭✭ meelick


    Here's a quick update now that I have the battery working. I was able to get the battery charging at night between 2-4am (1/4 price night rate), as well as topping up the immersion without interrupting each other. All pulled from the grid, then at 4am switched back to powering the house from the battery. :)




  • Registered Users Posts: 791 ✭✭✭ reklamos


    Why your battery charge rate is slopping down after about an hour? Is it intentional or is there something that starts limiting it? To make most of your money I would move water heating closer to use time. Having hot water sitting and cooling down is a waste of energy. What doe you use for impersion Eddi/iBoost?



  • Registered Users Posts: 108 ✭✭ meelick



    On the charge slope, I believe that's the charge curve of the battery, CVCC, so once it gets to the target voltage, it ramps down the current till it gets to 0.5c rate, at which point it's charged. On my tariff, 2am to 4am is the 1/4 price rate (7.5c/kWh). Anything outside that is 1/2 price rate (15c/kWh till 8am). You might be right on moving the Eddi boost time. I'll try boosting immersion closer to use time, but each unit later in the night costs double, so I'd only want to put it on for half the time, and see if it ends up at the same temperature. I'll give it a go. Yes, Eddi for the immersion.



  • Registered Users Posts: 791 ✭✭✭ reklamos


    Interesting. It starts sloping after 1 hour, so you only put have 3kWh before it started sloping. Since I do not see SOC I assume that the battery was above 50% otherwise it starts slopping too early.



  • Advertisement
  • Registered Users Posts: 2,586 ✭✭✭ yankinlk


    Wait. Is anyone complaining of cold showers? Interested for when I am forced to smart meter. ATM I'm day night so I boost the last hour and no one has issues with hot water.

    But I'd try what you have setup to save max money if it stil provided comfortable showers



  • Registered Users Posts: 108 ✭✭ meelick


    Exactly, I'd estimate the battery is between 11-12kWh, but had only discharged about 40%. I've it set to depth of discharge of 80%, but even then, I'm not hitting anything close to that overnight (at this time of year).



  • Registered Users Posts: 108 ✭✭ meelick



    Not so far, decent showers in the morning, but I'd estimate I'm only getting about 3-4kWh of energy into the cylinder. I have 4 temp sensors attached to it, and the bottom never gets much about 20degC, where the top sensor shows about 63degC. Thinking of longer immersion element or getting a willis immersion fitted. I've been told that I could get much more energy into the cylinder that way, up around 6kWh, so a lot more hot water that way. Current setup is not circulating water at all, so it's all sitting at the top. The average of all the sensors drops from about 44devC to 42degC between 4am and 8am.



  • Registered Users Posts: 3,302 ✭✭✭ graememk


    Or a de-stratificion pump? The relay board for the eddi can control that.

    But your right, only the top bit of your tank is getting hot and the rest is sitting cold.

    Another thing to check is it wired into the bath element rather than the sink element



  • Registered Users Posts: 108 ✭✭ meelick



    Good suggestion, I'll look into a destratification pump as well. Eddi wired into both sink and bath elements, it's definitely set to bath, the sink setting heats far less. My problem in controlling the pump from the eddi is that it's downstairs in the utility, whereas the cylinder is upstairs, and I've no easy way of running a cable to the pump from the Eddi.



  • Registered Users Posts: 3,302 ✭✭✭ graememk


    Possibly if your looking to disregard the sink element you might be able to reuse the wire for that.



  • Registered Users Posts: 791 ✭✭✭ reklamos


    Why are you charging overnight then when there is plenty juice in the battery and we have sunny days? I only charge at night if battery is low and also based on solcast forecat for the day.



  • Registered Users Posts: 108 ✭✭ meelick



    I reckon that the cost of a kWh charge/discharge in/out of the battery costs about the same as the cheap rate between 2am and 4am (in battery lifetime reduction), so I'm using the grid rather than reducing the life of the battery.



  • Registered Users Posts: 1,766 ✭✭✭ bullit_dodger


    I think you've got the math wrong there meelick. Most batteries have a lifetime duration in the 6,000-10,000 range. Assuming you (fully) cycle the battery everyday that's 365 times a year. So you're looking at ~20 years for some batteries. Even at that even at the end of the published lifetime, the battery isn't dead, just that it will perform at (say) 70% of the initial performance.

    Batteries are there to be used - that's why you bought it.



  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 60,486 CMod ✭✭✭✭ unkel


    You're mixing up chemistries. Most of us use LiFePO4 which has several thousand cycles, but he is using lithium ion 18650s, which typically have several hundred cycles. So he is very prudent not to cycle the bejaysus out of them! And apart from the cost of the battery, I'm sure he doesn't want to weld together again 1400 batteries every other year 😂

    11PM: 15kW o'clock!



  • Advertisement
  • Registered Users Posts: 1,766 ✭✭✭ bullit_dodger


    Missed the connection there alright. Yeah that makes a bit more sense now....



  • Registered Users Posts: 182 ✭✭ daughy


    I posted this on another thread, and not sure if it was supposed to be on that section, I'll try here instead if anyone can help..

    I'm new to batteries so be kind.

    I recently had delivered two, 48 volt, 100 amp prebuilt batteries from alixpress.

    I have paralleled them, and all is fine.

    I have connected them by Can, to my solis hybrid rhi 5k 48ES, after I activated the batteries using user defined it showed me the soc on the hybrid screen, and it matched what the battery screen said, I boiled the kettle to check for outgoing power and the sokis display showed up to 2kw coming from the batteries, it was a bad day for solar but the solar was charging the battery, both batteries worked parallel to eachother. Each taking 20 amps from the battery when the kettle was activated.

    My issue is using user defined mode,

    If I set the equalisation voltage and the float voltage the same, and the float current to 0 amps, and floating time to 0, will this eliminate floating and equalisation.

    Reading about lithium it says they don't need a float charge or equalisation.

    The solis app didn't show the bms, or the soc of the battery even though the inverter display shows a percentage of the battery on screen.

    I could switch battery type to pylontech or some other battery type but unsure as my battery pack consists of 16 cells.



    Any help would be appreciated

    Post edited by daughy on


  • Registered Users Posts: 2,569 ✭✭✭ daveharnett


    The solis inverter uses an rj45 connector for it's CAN connector. Which pins does it use for CAN H and CAN L? I've tried probing all of them looking for a 120Ω resistance, but couldn't find it.



  • Registered Users Posts: 3,302 ✭✭✭ graememk




  • Registered Users Posts: 19,003 ✭✭✭✭ ELM327


    What make is the battery? Unless it's listed in the Solis you'd have to use userdefine and then enter the parameters from the spec sheet of the battery bank.



Advertisement