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Everything posted by Solo

  1. Our estate uses 24V Mecer lookalikes, with 2 * 12V 105AH Enertec deep cycle batteries. A very common event is that 1 battery gets tired after 2-3 years, and either will not hold a charge, or will not charge beyond 12.5V I know it is not good practice to replace 1 battery only, as the batteries are now unbalanced, but most of the above failures are due to unbalancing anyway. What is the worst that can happen if one replaces 1 battery only, and monitor the balancing going forward with a voltmeter? If the older battery fails, it was due to be replaced anyway. If the new battery fails, that would be a good reason not to mix batteries, but why would it fail if the charge voltage was correct? I am trying to avoid scrapping a battery that still has a few years life, or is this really not a good idea? Would welcome your views.
  2. This looks interesting:) Defy is launching a hybrid solar mains fridge and freezer this month (Feb 2021) 3 * 30W panels come with the appliance and use solar power to keep the fridge or freezer powered when the sun is out, falling back to mains as required. https://stuff.co.za/2021/02/11/solar-hybrid-fridge-freezer-south-africa/ https://www.businessinsider.co.za/defy-launches-solar-powered-fridges-freezers-in-sa-costs-under-r6000-with-panel-2021-2 https://www.defy.co.za/solar-hybrid
  3. Thanks for the suggestions! I presume Sonoff would need an App or Wifi connection? After some research I am looking at one of the following 1. Sinotimer (12V option available) TM618 Universal Input 5V 12V 24V DC/AC 7 Days Programmable Weekly Timer Module for Gate Automation and Solar Controls Usage: The TM618 timer MODULE can open or close kinds of electrical apparatus and power automatically, according to the preset time, the items can be streetlight, neon light (sign), billboard, electrical appliances, broadcast equipment etc... 2. Omron H5F (220V only, no battery backup) • Up to 12 ON/OFF operations (24 for pulse-output operation). • Special holidays can be handled easily with the holiday setting function. • Adjustments for sudden schedule changes can be made easily using output override and automatic return operation. • The operation program can be checked easily with the program check function. • Enables pulse output operation and summer time setting. • Incorporates finger-safe terminals. • Conforms to UL, CSA, and CE marking. • Meets a variety of mounting requirements: flush mounting, surface mounting, and DIN track mounting.
  4. Question for the techies out there:) I am a trustee for a body corporate, mix of commercial and residential units. Access control is the normal sliding gate. The current Centurion gate motor does the job just fine, but we would like to tweak the operation slightly The Centurion gate controller has a built in timer, and we use this to open the gate at 6am and close it at 7pm (Mon to Sun) The gate has to stay open 6am-7pm for the commercial units (medical centre), but after 2pm Sat and all of Sun, we would prefer the gate to close. The current setup does not allow for different times at weekend. Previously we had a separate Majortech style timer, mains powered with battery backup, but it was unreliable, compared to the current 12V Centurion timer. I would like something more like a Geyserwise controller, or inexpensive PLC. Very reliable. Preferably 12v powered Relatively easy to program. What do the experts recommend? I have never used an Arduino or Pi, but if they are the answer am prepared to give them a go. Thanks!
  5. One Deal a Day has this on offer
  6. This is very normal. I have noted this with Enertec batteries, and the battery data sheet confirms it, there is a sharp drop initially to approx 24.8V within the first 15 minutes, then a long flat discharge of several hours to 24.0V
  7. Hi iops, Slightly off topic, but I would like to ask you about your Synapse 3.0+ 24V inverter, as the residential complex I live in on the KZN South Coast has a few of these units installed, together with many CBSolar 24V inverters and a handful of Mecers The CBSolar inverters have been the standard for 2 years and apart from a few failures have performed well. We are still getting to know the Synapse and Mecer. One issue we have noted with the Synapse 3.0+ is that the fan runs continuously, this is not the case with the CBSolar and Mecer. Do you know if the Synapse is a Voltronics, or a clone? Who supplied the unit to you?
  8. I understand that when [05] is set to Use, that this enables [26] [27] [29] What are the results of using Fld and Agm? Fld seems to force 26,27, and 29 to the default values? Does Agm do the same? When would one ever want to use Fld or Agm? It is very confusing to have setting 5 default to Fld, not realizing that it has an impact on other important settings!
  9. Veerry interesting, thanks McDuffy!
  10. Hi McDuffy, How do you measure your battery voltages - external voltmeter, Axpert display, or RS232 port and PC? I would really like to see a comprehensive test of the Axpert performance, but using lab equipment to accurately measure volts and amps. Not sure I trust the measurements displayed by the Axpert Regards, Solo
  11. Impressive! Did you import the Flukso unit directory from the suppliers, or are they available locally?
  12. Hi Macduffy, Very interesting discussion! I have been involved with the inverter/battery setup on a residential estate in KZN, for a period of approx 2 years. The estate has approx 100 households, each equipped with CB Solar 3000W (Axpert) inverter and 2 * Dixon or Enertec lead acid batteries in series (24V) We have seen very similar results to your tests. After 2 hour load shedding, with 100W load, the inverter returns to float very quickly. On days when there are 2 load shedding outages, the batteries do not recharge properly between outages, and we have had some batteries undercharge. We have had to recharge some batteries, and have rescued some before they suffer permanent damage. Our biggest issue is the installer not changing the battery low voltage cutoff setting from the default of 21.0V to recommended 23.5V, this has permanently damaged several batteries. Another issue is unequal charging of the 12V batteries in series, one battery always suffers unless a battery equaliser is installed.
  13. Good discussion, I am taking notes! I would definitely try charging the batteries before going to all the cost of replacing them. I suspect they have been undercharged, the fact that they last 2 hours may be a hopeful sign.. We had 100Ah batteries which lasted 20 mins. They had been severely discharged, several times.
  14. PS AGM and gel batteries do not have electrolyte like lead acid batteries. Cannot be topped up, so be careful not to overcharge, but it looks like they will accept 40A, so I guess low risk of overcharging with a Ctek or PDS008 charger, I doubt these will supply 40A
  15. Hi AScheff, I am still learning about Axpert and batteries, but in my my opinion if you act quickly, there is a chance you can rescue the batteries by charging with a good external battery charger. One that can supply a high charging current, which may be able to correct any sulphation on the battery plates. As your batteries are sealed just have to be careful not to overcharge and lose electrolyte through gassing, as the batteries cannot be topped up. How to charge the batteries: 1. Take them to a battery expert with charging equipment. 2. Buy a good charger Hawkins are a good local make. These are manual chargers, use with care. They have a sticker 'do not use on sealed batteries' Ctek make high quality smart chargers, quite pricey, but quality chargers. Midas sell a PDS008 charger for less than R1000, highly recommended by the 4x4 community for rescuing abused batteries! I used one of these yesterday and was quite impressed. Both Ctek and PDS008 are so called smart chargers, they have many phases of charging which do various things to the battery, compared to the manual chargers which just use a brute force charge. Both are good, a charge is a charge! If you buy a charger, disconnect your batteries, connect the charger and charge each battery overnight, one at a time. Reconnect the batteries and hold thumbs, hope that the charger has paid for itself. Let me know what happens, I would be interested in the outcome! Omnipower are good batteries. Sealed for low maintenance, but probably can be opened to check water level. Of course this will invalidate the warranty. If you have a good supplier contact, might be worth asking them for advice. Good luck! Solo
  16. https://www.scientificamerican.com/article/to-store-renewable-energy-try-freezing-air/ This sounds like something Eskom could use instead of pumped water storage and diesel
  17. On my solar geyser installation, the pump icon has never displayed, though the pump runs, and all works fine. I suspect it is a bug/fault but I never took any action as the system works. Watch your temps, if they reach 7 deg diff then rapidly equalise, then your pump is working
  18. For more info, see Graham's blog http://www.technowizard.co.za/companyproducts/item/78 A tangle of wires covers the floors and snakes through much of the space in a cramped room in Graham Robjant’s Durban home. The electrical technician is completely off the grid, and we are in Robjant’s control centre, where he monitors the power he produces. There are gauges, measuring things like how much power is being used and how far the batteries are charged. It’s here that the power from the solar panels at the Glenwood home passes through an inverter to produce usable current to power the house. Solar panels are built into the side of Robjant’s house and hang over his fuel-efficient motorbike. It has been the 57-year-old’s dream to be self-sustaining, and a little inheritance money allowed him to upgrade his initially shaky power system to six solar panels, dozens of batteries and a generator last September, making him self-sustaining. Graham Romjamt has designed a solar energy panel.Picture Zanele Zulu .20/08/2013 ZZ INLSA With load-shedding a threat and electricity prices rocketing, Robjant’s efforts offers are an example of what homeowners can aspire to. They also fit in with eThekwini Municipality’s enthusiasm for renewable power. The senior manager of eThekwini Energy Office, Derek Morgan, said the municipality was the first to allow power producers – typically in industry – to feed into the grid and was also looking at ways to facilitate this for micro-scale residential power producers. The municipality was also the first to have an agreement to buy excess power from independent energy producers. NCP Alcohols, in Durban, was one of the first companies to take advantage of the power-purchase agreements. It produces power while being embedded into the municipal grid. It has been producing its own power since the 1960s, and is one of six embedded generators in KwaZulu-Natal. Carl Freyer, NCP Alcohols’ engineering manager, said the company had a gas-fired high-pressure boiler that supplied steam to a turbine generator, providing up to 3MW of power. Thirty tons an hour of lowpressure steam is a by-product of the production process. NCP saved R9 million a year on electricity and had a gross income of about R1.5 million from the exported power. Robjant can produce 8000W with his six solar panels and generator. He can survive a week of bad weather before having to depend on the generator. With only a few companies able to take advantage of the power purchase agreements, Morgan said the municipality was looking at the legislative barriers in a forum, in collaboration with South African Local Government Association and Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ, the German Society for International Co-operation). The legal and technical requirements of feeding in to municipal grids are under discussion. Some of the thorny issues being tackled include standardised technical requirements for meters that can credit both ways, billing system adjustments for feed-in, standardised wheeling agreements – how electricity is transmitted to different areas – and clarity on the legal restrictions facing municipalities buying electricity. The municipality has produced a document detailing the hurdles to embedded generators, including high start-up costs and short contract times, which make funding difficult. It was possible to get longer contracts that were more attractive to financiers, but with a large number of customers this would pressent an administrative nightmare for the municipality. Melita Steele, a climate and energy campaigner for Greenpeace, said the unclear regulations were a barrier to investment. She cited Germany as an example where people were paid for their excess electricity. The National Energy Regulator of South Africa had standard conditions for embedded small-scale generators, which approved small-scale generation of 100kW or less in reducing energy demand. All of the administrative work has to be done by the municipalities, who report yearly to the energy regulator. Hilary Joffe, Eskom spokeswoman, said mechanisms were in place to enable grid connection for large generators. Eskom was investigating how to extend this to smaller and microgeneration. It was also involved in the Salga and GIZ forums. ... PATH TO SELF-SUFFICIENCY Graham Robjant has been generating his own power for about 12 years and no longer has an electricity meter. His journey to power self-sufficiency has, however, involved a lot of red tape. He had officials coming at him from all sides. His house in Glenwood was built before 1927, which means it is listed and he was fined by Amafa, the heritage agency, for building his panels into the wall. An eThekwini official stopped him from continuing with the panels and asked that he produce house plans. Consultations with an architect meant further payments. Robjant also had to pay fees for an structural engineer to check the structure was stable, although he had already consulted an engineer when he set up the panels. He is now waiting for the geographical survey to measure whether the land is stable enough to handle the structure, which weighs less than a car. This is despite his home being built in a geographically stable suburb. For people keen to harvest their own power, Robjant suggests starting small with a solar panel and battery, and using Eskom as a back-up. He said people should consult with experts first. – Cadet News Agency [email protected]
  19. As an intro, I have been browsing Powerforum for 18 months, with a general interest in solar, but my only post being a question about batteries and inverters being used on a residential estate (KZN South Coast). The issue we had with the battery backup systems went away after the faulty units (many of them) were replaced by the vendor and the estate developer. I find the forum very useful, but as an educational resource for newbies, a bit lacking in tutorial and intro material. Recently I ventured onto Youtube and entered 'solar power system for home in south africa' in the search bar. Wow, some very useful videos of local solar installations! Check this one out, it is dated, being posted in 2012, but I found the content extremely relevant, as it was submitted by Martin Lorton from Cape Town, and explained why grid tie installations in SA, were often unable to feed excess power back into the grid, so his solution combined a Victron Grid Tie inverter for use during daytime hours, as well as a Victron Quattro, programmed to disconnect the grid after hours. https://www.youtube.com/watch?v=agSfgsH97PE As a tutorial, the addition of a video clip, made the content so much more useful, I would be interested in other forum users views.
  20. Thanks Plonkster! Are you recommending a 200AH battery and a higher cutoff voltage? If so, what type of battery (Lead Acid, AGM, Gel) etc and possible vendors? What about battery monitors and voltage equalisers? Is there any benefit in trying to rejuvenate the dodgy battery that seems to exist in most installations, by individually charging them. I suspect that the suspect batteries may have sulphated, and could have some more life in them.
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