Jump to content


  1. Renewable Energy

    1. Starting In Solar? Feel free to introduce yourself

      Starting in Solar? New Comers Feel Free to Ask- There is no such thing as a silly question.

    2. General Discussion

      General discussion & Latest renewable energy news

    3. Questions & Answers?

      Unrelated To Renewable Energy. E.g. How To Prepare A Wall For Painting?

    4. Off Topic

      Off topic discussion, World News & Current Affairs

    5. Product Opinions & Reviews

      Renewable energy product opinions, reviews & questions

    6. Member Installations Showcase

      Please feel free to showcase your renewable energy installation, share, upload images & installation descriptions

    7. Solar Power

      Solar power discussion

    8. Wind Power

      Wind power & Wind turbine discussion

    9. Batteries

      Batteries, battery monitors, chargers, accessories & battery care

    10. Inverters

      Off Grid & Grid Tie inverters

    11. 160
    12. Accessories

      Cables, Circuit Breakers, Fuses, Electrical Accesories

    13. Water Heating & Pumping

      Water heating & water pumping solutions

    14. Hydropower

      Hydropower or water power is power derived from the energy of falling water or fast running water, which may be harnessed for useful purposes

    15. Sustainable Landscaping

      A sustainable landscape is a stable and productive ecosystem that conserves the physical and biological processes occurring on that landscape. Designed and managed sustainable landscapes maintain hydrological function, plant and animal diversity and biomass, soil integrity, and contribute to human wellness. Utilizing nature and landscape to promote energy efficiency and energy saving.

    16. Energy Use & Conservation

      Saving energy, energy saving appliances & tips

    17. Electric Vehicles

      An electric car is an automobile that is propelled by one or more electric motors, using electrical energy stored in rechargeable batteries or another energy storage device

    18. Alternative Fuels

      Some well-known alternative fuels include biodiesel, bioalcohol (methanol, ethanol, butanol), chemically stored electricity (fuel cells), hydrogen, non-fossil methane, non-fossil natural gas, vegetable oil, propane, and other biomass sources.

    19. The Internet of Things

      The Internet of Things (IoT) is the network of physical objects—devices,other items embedded with electronics, software, sensors, and network connectivity, that enables these objects to collect and exchange data. Such as : Raspberry Pi, Arduino

    20. Fundamentals Of Electricy

      Principles of Electricity, Theory , Calculations

    21. Industry, Product Hypes, Fads & Rants

      Hypes, Scams, Rants, Unproven Tech, Does it really work?

    22. Useful Resources

      Share Useful Resources

    23. Design Software

      Software to aid in the design of Renewable Energy Systems.

    24. 211
    25. Electronics & Tools

      Gizmo's , Ipads, Tablets, Smart Phones, Tools, Power Tools

    26. 60
    27. Group Buys

      Buying as a group local or abroad.

    28. Hobbies

      Gadgets, Electronics, Fishing, Cars, Remote Controlled Vehicles, Drones, Photography, Camping, 4x4, Boating. Anything Goes :>

      • No posts here yet
    29. Classifieds

      For sale and Wanted
      Commercial Suppliers Please make use of the Commercial Supplier Section

    30. Job Centre

      Post job opportunities here, or upload a copy of your CV if you are seeking employment in the renewable energy sector.

    31. Commercial Suppliers

      Suppliers to sell goods on the forum as part of a business. Companies, Sole proprietors and anyone who wishes to advertise products for commercial purposes are most welcome. To apply please visit  http://powerforum.co.za/subscriptions/

      • No posts here yet
    32. Forum Suggestions & Support

      Suggestions & ideas are always welcome to improve Power Forum

    33. 31
  2. Other Top SA Forums

    1. MyBroadband - Broadband, Internet, gadget and technology discussions   (650 visits to this link)

      Get your broadband and tech questions answered and share your thoughts on gadgets, SA’s Internet and cellular networks.

      My Broadband |  Test Your Broadband Speed | South African Technology News

  • Who's Online   1 Member, 0 Anonymous, 9 Guests (See full list)

  • Member Statistics

    Total Members
    Most Online
    Newest Member
  • Topics

  • Popular Now

  • Posts

    • Thanks for all the help and replies. I really appreciate it! I'll go through it properly tomorrow when I have electricity again  Quick question:
      Will the MultiGrid be able to work with PV without having batteries or an MPPT or will I need an MPPT or both in order to power from PV? (From what I've read it seems that I need a seperate solar inverter without batteries & MPPT, but I'd just like to confirm) The idea I have now (if the above is possible) is: Get a small generator once I start to keep the home office running in the unlikely event of an outage. Get the MultiGrid and PV to start making use of some PV Get an MPPT and battery/s (Or just battery/s if MPPT is required to start generating with PV Obviously the battery/s will be a big expense, so if it can be delayed due to me having the generator that'll be great as I'm hoping the LFP prices will keep going down.
    • Let me get technical (because I love it), and bolster my story with some math! If you draw a chart with time on the horizontal axis (let's say in hours) and current on the vertical axis (in ampere), then if you consider the area UNDER the line, it would be current multiplied by time, or amp-hours. If you've had calculus training at some point in your career, then you know the procedure for calculating the area under the line is known as integration, and if you've done any applied mathematics and/or numerical analysis type courses, then you know there are ways to approach the area using various techniques, the simplest which is newtonian integration. Newtonian integration essentially draws little narrow trapeziums below the curvy line and work out the area of each trapezium, and add them all. There are even simpler methods where you draw a narrow little rectangle so that the middle of the rectangle is on the top line (or consider converting a line chart to a bar chart so that there are millions of little rectangular bars for each data point). Again, the area of a rectangle is simply width times height, or in this case, current multiplied by delta-T. This is basically exactly what the BMV and the Multi does. The reason the Multi could not do it when you had DC chargers, was that it didn't know about "external" current. So the obvious answer is to make it aware of it. And it really is that simple. Every couple of seconds, you take the combined current from all the MPPTs and tell the Multi that "by the way, there's also this 52.3A coming from somewhere else", and then the Multi adds it in when doing its little integration dance. The result is an SoC determination that isn't 100% accurate... but guess what, lead acids aren't that consistent anyway, lithiums don't really get hurt if you're off by a bit, and it's a thousand times better than using the voltage to estimate it (at least for lead acid).
    • And there I learn something! My upgrade path after my Phoenix (if it ever goes) is then all set for a Multigrid, have all the parts. Sell the BMV and to offset some of the new inverters cost. :-) 
    • There is rather a lot to explain and I don't want to overcomplicate things at this point. But let me put it simply. IF you have a Venus-GX, and all your solar chargers are Victrons, then you don't need the BMV. The Multi already has the ability to track the state of charge, and the Venus-GX tells the Multi about what the solar chargers are doing, so the Multi keeps a good state of charge even without a BMV. This also makes switching to and from the grid easy or even run grid-parallel. But if you decide not to go with a Venus-GX, then I would suggest getting the BMV instead. There is a way to configure the Multi so it takes a signal from the BMV to switch to and from the grid. This is a hard-on/hard-off configuration, it does not mix power from different sources. Also, when you later buy your new LFP battery, the BMS of that battery will tell you about the SOC and you won't need the BMV anymore. If it was me, I'd get the Venus-GX and leave the BMV, unless I had money to burn. It may sound odd... but it isn't, if the chargers are all victron and there are no DC loads, and you have a Venus-GX or CCGX, you don't need the BMV.   The day my wife bragged to her colleagues in the office was the day I knew she bought in. The power went out, and she announced that she's going home because there's power there... Something else to be said about this: It's not going to help that you have power, but your internet connection goes down because some part of it runs from the grid or has only limited backup. Make sure you have more than one internet connection if it is really important to you.
    • The Multiplus-II has a steel case, where the others have aluminium cases. The Multiplus-II is also not significantly cheaper (in fact it is bout 20 Euros more expensive), but it does pack a bit more features. It has slightly lower no-load consumption and it has the anti-islanding features of the Multigrid. But it also costs the same as the Multigrid. The only other feature it has is a detachable current sensor, so in an ESS setup it saves you some money on adding a separate energy meter. The Multiplus has a higher-rated transfer switch though (be sure to get the 35-50). Also see here. Personally I'd get the Multiplus, or possibly the Multigrid if it is not too much more expensive. Difference? The Multigrid is certified for NRS097-2-1, in other words, it can be tied to the grid in South Africa. The Multiplus only complies with NRS097-2-1 if you add another anti-Islanding switch. The easysolar is nice and all, but doesn't in my mind represent much of a saving over individual components, and it sort of commits you to an all-at-once decision. I personally prefer multiple smaller MPPTs rather than one large 150/70. Also, if you go 24V (nothing wrong with that), it limits your battery choices later when you want to go LFP. In terms of the best value options available now: You'd be limited to the FreedomWon Lite-mini battery, as that is one of the few 24V batteries made locally.
  • Popular Contributors

  • Blogs

  • Files

  • Forum Statistics

    • Total Topics
    • Total Posts