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  1. J

    Begginer working my way up - Am i beating around the bush?

    I have one test setup similar to what you are doing and that can help you understand the limits of what you are trying. I have a 18650 8S2P battery made out of 2,5Ah LG cells. I am discharging it with a 590W MPPT grid-tied inverter. The MPPT function determines the best discharge point is at...
  2. J

    Different grid-tied inverters in one grid possible?

    There is an arrangement of listed brands and models; the ones from aliexpress are listed as "Others" and have to be manually introduced. I don't know what checks are happening in such situation; I just received the confirmation that I am successfully registered as exporter and may start...
  3. J

    Arguing with Aliexpress vendor. Maybe I’m wrong?

    Depends on how you ask the refund. In these situations I normally follow this method: 272Ah/280Ah = 0,97; therefore If price is 500 eur. (1-0,97) = 15 eur. refund and I normally add a little plus for the inconvenience; so maybe 30 eur. total.
  4. J

    Arguing with Aliexpress vendor. Maybe I’m wrong?

    You can just take a pragmatic approach claiming the 272Ah out of 280Ah come from the 2 defective cells and from there claim a proportional refund. This because the difference is not very big; I would personally test the two cells individually only If the difference was big to know If the missing...
  5. J

    Different grid-tied inverters in one grid possible?

    Answering a bit your comments. First, I do have an agreement with my energy supplier to export electricity so doing that is not a problem. Second, risks of using cheap Aliexpress grid-tied inverters (even individually) is probably there. They have certifications, either one or both claim to...
  6. J

    Different grid-tied inverters in one grid possible?

    Thank you for your comment. I so rationalized it this way too and the example of the neighbor makes it clear, specially If it is the neighbor next door being connected to the same grid. The grid tied inverter produces a higher voltage to pump current to the grid. Depending on how much solar is...
  7. J

    Different grid-tied inverters in one grid possible?

    Ok, thank you Quattro, I will stay in the conservative side. I will not use them together and If I still did, only in the night when the inverter connected to the panels is off.
  8. J

    Different grid-tied inverters in one grid possible?

    Dear solar enthusiasts, I have two solar grid-tied inverters; #1 - 600W 24V grid-tied inverter for two 100W solar panels I have at the balcony. #2 - 590W 12V grid-tied inverter with battery mode (adjustable discharge 60-250W without MPPT function) for a 12V lifepo4 battery I have and possibly...
  9. J

    Daly BMS Will Not Balance

    Answering you both. First some information: - I have a 14,6V 2A LifePo4 low-cost charger from Aliexpress. The charger stops charging as soon as total battery voltage reaches 14,6V and won't resume charge unless I disconnect it and plug it in with a battery voltage below 14,6V. - The battery is...
  10. J

    Daly BMS Will Not Balance

    Thank you very much for your extended and carefully written answer. It gives me huge peace of mind honestly; having a battery with unusable capacity would kill me, but that is not the case. Actually new things happened. I have charged the 4S LifePo4 12V 60Ah battery with 2A charger for 24h...
  11. J

    Daly BMS Will Not Balance

    I am having the same issues. Second time charging the cells (12V 4S) and the balancing function turns on at will. One of the cells is falling short on voltage 3,35V instead of 3,65V. I have seen the balancing function working sometimes, it switches on for seconds, but now it won't which means I...
  12. J

    Free Energy Generators

    I have an e-motor with a flywheel of 50cm attached to a e-motor with a flywheel of 5 cm. When the first e-motor rotates, the difference in diameter multiplies the energy 50/5 = 10 times. The rotation of the smaller diameter motor receives 10 times the energy consumed by the other e-motor; after...
  13. J

    Daly Smart BMS not registering small loads

    My experience is similar. The 12V 60A Daly smart BMS reads the charging power of 18W but can not read a load of 5W or lower passive drains. Will soon try a 60W drain.
  14. J

    Growing voltage difference while charging LifePo4 battery at SOC 99% (Daly BMS)

    After careful consideration I let the charge continue. The voltage difference grew up to 0,3V while the SOC did not go higher than 99%. After disconnection it took hours for the batteries to have a similar voltage again; I could see that the batteries charged to 3,7V took longer to reach the...
  15. J

    Growing voltage difference while charging LifePo4 battery at SOC 99% (Daly BMS)

    I am charging a 12V LifePo4 battery with a 14,6V LifePo4 charger (2 Amps). The battery has 4 LifePo4 cells (60Ah) hooked to a Daly smart BMS and a solar charge regulator PWM (battery connections). In the same battery connections of the PWM I have connected the charger which therefore can supply...
  16. J

    Dutch PowerWall live and kicking

    That is cool, I was hoping to do something similar at smaller scale since the net metering is ending soon in NL. I did not fully understand the specs of your installation. You have 3,5KWh of solar? you mean 3,5KW? You forecast your consumption to be 4,5KW? You mean 4,5KWh per day? And then the...
  17. J

    Should I get a lifepo4 battery charger?

    You can use a charger to have the battery charged up to 100% at any necessary time; specially when you want to make a test (eg. capacity test). If you do not want to spend a lot of money on it you can buy the cheapest Lifepo4 charger on Aliexpress for about 5 euros. It has a DC connector so you...
  18. J

    Using solar micro inverters with batteries instead of panels

    While feeding the inverter with a battery outside of the MPPT range is probable the best option, I can add that I have recently fed a MPPT inverter with a battery within the MPPT range and it has not caused any apparent issue. Also, not sure If as result of the MPPT function, the inverter has...
  19. J

    Testing grid-tied inverter with battery

    I very much think you are right. MPPT range is smaller than VDC range and so you can feed the inverter with the MPPT function off. The small C-DC buck I have or the new one does not reach such voltage, so I guess the test will happen in the MPPT range instead. I will try.
  20. J

    Using solar micro inverters with batteries instead of panels

    Well, things are about to get interesting now. We have just received the same inverter (just different label on it but clearly same model). I am waiting for the current meters (DC) to start analyzing the performance, the starting power and other parameters of the inverter. As kundip mentioned...
  21. J

    Using solar micro inverters with batteries instead of panels

    I could not perform the test as explained in the originary post due to suspected defective DC-DC buck converter. (Buying at Aliexpress is tricky...) I also wonder If an undersized battery could be used for such test even If just for a few seconds. Without current limiting, the test seems risky...
  22. J

    Testing grid-tied inverter with battery

    I could not perform the test; the brand new DC-DC buck converter from Aliexpress acts weird. It only allows voltage regulation when no load is attached to it. As soon as a load is connected; this shows signs to receive some little current but then the voltage gets crazy and starts fluctuating...
  23. J

    Using solar micro inverters with batteries instead of panels

    Does not the load of a grid tie inverter addapt to the supply when limited? Otherwise how can 100W of solar panels work with a 600W grid tie inverter?
  24. J

    Using solar micro inverters with batteries instead of panels

    Dear all, This weekend I will try feeding a 600W MPPT grid-tied inverter with batteries and a DC-DC buck converter with current regulation (max. 5 Amps). https://diysolarforum.com/threads/testing-grid-tied-inverter-with-battery.32173/ After the test I will post results. Feel free to comment...
  25. J

    Testing grid-tied inverter with battery

    I have just received a 600W MPPT grid-tied inverter from Aliexpress [22-60VDC, 220V AC] (see link) and I would like to test it without solar panels. In order to do that I have thought of using a 8S 2P 18650 battery in combination with a DC-DC buck [Input: 8-36V ; Output: 1,25-32V] with current...
  26. J

    Putting a DC wattmeter between solar panel and MPPT controller possible?

    Thank you very much for your answers and clarification. The panel arrangement is 2S 16VDC 100W panels with a max. 6,25A current. Therefore I found this nice PZEM015 for it. The plan is to put the wattmeter between the panels and the grid tied inverter. The setup has no battery; all production...
  27. J

    Putting a DC wattmeter between solar panel and MPPT controller possible?

    Just a check here. Since the MPPT controller just varies the circuit resistance to allow the panel delivering at its maximum power point (best combination of Voltage and Current), placing a DC wattmeter (with external battery) between panel and controller should not negatively influence the...
  28. J

    Build Hypothesis

    8h at 1400W (11,2 kWh) require more than 1400W. Say 4 good hours of sun (max. output) and 4 medium hours (60% output) in one day; this is 6,4KWh per KW of solar panels. So 11,2/6,4 = You need 1750W. And that is an optimistic sunny day, only 8h of pumping (no 12h) and without inverter loss. So my...
  29. J

    Grid tie inverter with charge controller?

    Without reading all the later messages, I just want to say that there are quite a lot of devices that do what you ask. I though they call them hybrid inverters and since they are smart, they cost 300 dollars (rare) and easily much more. In Aliexpress I have found inverters which to some extend...
  30. J

    Grid tie inverter with charge controller?

    Could it be a solution to use these cheap chinese PWM and a grid-tied inverter together? (Together around 90-100 euros) Like you connect the panels, the battery with BMS and the inverter to the PWM controller and then you find a way for the battery to operate at a high overdischarge voltage...
  31. J

    Balcony mount on railings for 100W flexible panel

    Dear all, I want to share with you my upcoming design for a flexible solar panel mount. I live in the Netherlands and would like to harvest some solar from my rental apartment. In this apartment I only have the balcony as possible collection point (see photo). Until now I just had a rigid...
  32. J

    16V 32 cells panels valid for 2S setup with grid tied inverter?

    The cheaper I go, the more experiments I can make. I do solar at a hobbye level, so I try to limit costs since I do not have financial returns. You are right, only that in the theory, in the Netherlands where I live, I only had to fill in a very short form and the company already started...
  33. J

    Is exceeding the maximum PV input voltage by a little bit okay?

    Very convenient topic. What would you think about a VOC of 57,5V for an MPPT inverter that can not tolerate more than 60VDC? Theoretically at 0*C the VOC could reach the 60V.
  34. J

    Grid-tied inverter working during a grid shut-down?

    Hi Jose, a possibility on how to do that is explained here: https://diysolarforum.com/threads/sola-transformer-to-turn-on-grid-tied-inverter.28849/#post-386213 Pero dicen en las noticias que Espana esta más aislada de la red europea lo que hace que en caso de apagón aún haya menos...
  35. J

    16V 32 cells panels valid for 2S setup with grid tied inverter?

    Panel example is: https://www.aliexpress.com/item/4001186044126.html?spm=a2g0o.cart.0.0.38b23c008YZJ7B&mp=1 Inverter example is: https://www.aliexpress.com/item/32960153109.html?spm=a2g0o.cart.0.0.38b23c008YZJ7B&mp=1 My question is aiming a generic answer so only the specs become relevant...
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