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Sarel

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Sarel last won the day on October 13

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  1. Would you mind adding me to the VRM Portal for this install, it would be much faster to probe a few things?
  2. I had a look at your config file and all checks out. The above image that you posted shows CCL as 0Amps. This info is communicated from the BMS to the GX. No matter what settings you do, these 3 comes from the BMS. The 2 Charge and discharge currents in Batteryview (shown as CCL and DCL above image seems to be related as described above. Have you tried resetting the batteries and the GX? Also what GX do you have, CCGX or something else? Have the GX comms cable perhaps been unplugged, or not plugged in correctly like in only partially or are there bent pins maybe?
  3. What is worrying is two factors, firstly that the DVCC is not forced on. Secondly that the Battery software is not supplying the charge and discharge current to the GX. Normally with a connected battery, the GX rely on that info. Will dig into you file a bit later….
  4. I think your ESS was not setup correctly, it looks like from what you posted. Likely your dealer will have to fix this as it involves the VE.Bus setup using VE Configure. Have a look at this: Pylontech on ESS I take it the BMS Can port is connected to the GX (or the VE.Can port with proper speed adjustment) On the DVCC, as per the above article, the DVCC should read forced on, it's quite important. Chance are, in this case, some of the other required settings as per the article, may also then be suspect.
  5. Can you perhaps share your ESS and DVCC screens as well please? Worrying is that the battery view charge and discharge info went missing? I think, because of that the GX info reverts to 0 for CCL.
  6. Lastly on the generator capacity you should consider that in an off-grid situation, you generator should have enough power to carry at least some loads and be able to charge you battery bank. Sizing for this is a bit involved. Firstly how much current can you use to charge the battery with, ie. how much can the battery accept safely? Then how much on top of that do you need to carry loads? Can you adjust the battery charger to limit charging current o a lesser value? Or are the charger max amperage less than what the battery can take? Next point to consider for generator sizing is the bigger the battery, the longer it will take to charge. How long do you have to get the battery charged? All these point will need consideration and compromises as the budget will not be infinite.
  7. You may be aware of these already: Various Can bus interfaces for u controllers There are SPI or shield type boards available at the above link. It may allow sniffing on the Can bus. Soooo the rabbit hole entrance is here : https://www.karambasecurity.com/blog/2018-01-17-how-to-build-a-can-sniffer or here https://www.hackster.io/MyLab-odyssey/can-bus-sniffing-3730a5 and in the latter link they sniffed battery cell voltages in a car.
  8. Other will chime in, only addressing the generator here. Firstly, almost all smaller generators specifications are overly generous, by a lot…. Secondly, stay away from inverter generators, they have their place but not in Solar systems. They are very bad in high demand and fluctuating load scenarios. You cannot easily determine their response as in overload conditions, they prevent the rpm from dropping by just limiting the load. Stick with old style AVR types. Then oversize the generator capacity by at least 20-30% or even more if you can. Battery charging is the toughest loads for a generator to deal with. Oh and small generators are all specced to standby duty, not prime. This is from a generator manufacturer as to their duty cycles: Standby Power Rating Standby power rated generators are the most commonly rated generator sets. Their primary application is to supply emergency power for a limited duration during a power outage. With standby rated generators there is no overload capability built into the units. It is important to note that standby rated generators, under no circumstances, should run in conjunction with a public utility source. Standby power rating should be applied to the unit where public utility power is available. The typical rating for a standby engine should be sized for a maximum of 80% average load factor and roughly 200 hours per year. This includes less than 25 hours per year of running time at the standby rating. Standby power ratings should never be applied except in true emergency outage situations. Predetermined outages with the utility company, under UL guidelines, are not considered emergency outages. Manual load shifts for testing purposes can be performed with most automatic transfer switches. Prime Power Rating Prime power rated generators should be used in applications where the user does not purchase power from a public utility. Prime power applications fall under two distinct categories: Indefinite Running Time The prime power rating is the maximum power accessible at the variable load for an unlimited number of hours per year in a variable load setting. It is not advisable that the variable load exceed 70% average of the prime power rating during any operational period of 250 hours. If the engine is running at 100% prime power, yearly hours should not exceed 500. Overload situations should be avoided however a 10% overload capability is available for a 1 hour period within a 12 hour cycle of operation. Prime power is accessible for a limited number of hours in non-variable load situations. Limited prime power is intended for circumstances where power outages are expected, such as a planned utility power reduction. Engines in generator sets may operate up to 750 hours per year at power levels less than the maximum prime power rating. In these situations it is important to never exceed the prime power rating. The end user should be aware that constant high load use will reduce the life of any engine. It is recommended that any application requiring over 750 hours per year that the engine be continuous power rated. Continuous Power Rating Continuous power rating is used in applications where supplying power is at a constant 100% load for an unlimited number of hours each year. Continuous power rated units are most widely used in applications where the power grid is unreachable. Such applications include mining, agriculture or military operations. Elevations and Temperature’s Effect on Power Rating Elevation and temperature are factors to consider before rating the engine. The engine may be operated at 3,000 ft. of altitude and at a temperature of 100° F without deration for standby power rating. For prime power rating the engine may be operated at 5,000 ft. of altitude and at a temperature of 100° F without power deration. For continuous duty operations at higher altitudes, the engine should be configured to limit performance by 3% per 1,000 ft. of altitude and 1% per 10° F inlet air temperature.
  9. Hehehe see first paragraph on the doc I shared above: 1 Introduction This document describes the MK2 protocol, used to communicate with VE.Bus products. Note that implementing the MK2 protocol is a task which is not to be underestimated. It is a complicated protocol. There are other alternatives, with ModbusTCP being the most popular one. See our whitepaper ‘Data communication with Victron Energy products’ for more information:
  10. Modbus is easy in comparison, but Canbus it is. Victron adheres to the international standards, and extended it somewhat. VE.Can / NMEA2000 Canbus is the preferred protocol for third parties to communicate with our products. Our CANbus protocol is based on the NMEA2000 and J1939 protocols. You can request the link for this document from Victron here Look for this: Interfacing with VE Bus products - MK2 protocol it should get you started me thinks
  11. Alternate energy or fuels, what ya mean alternate, energy is energy, no…. Well yes and no. Let’s unpack this a little in terms of Solar generation. There are two ways we can harvest enough Solar energy via Solar PV panels. One is to generate enough to cover our consumption 100%, the other is to reduce or electrical energy consumption by changing over to other forms of energy, normally chemical (fuel) energy or other forms of Solar like direct water heating. This will reduce or electrical energy consumption, sometimes by a lot. In SA, our fuel prices are well regulated. All fuel types BTU values per unit is known and the relative pricing is done accordingly. Here is a table for clarity sake: Let’s compare electricity to LPG gas and to Diesel fuel. First LPG and Electricity. LPG gives 24 098 Btu per Liter (or 45 545 Btu/kg) and it’s density is 1.898 kg/m3 (15°C) (roughly 1.89kg/L). Let’s work on the average price of R30.00 per kg for LPG and electricity at R2.00 per kWh. For the same Btu value, electricity will need 13.34x more units to get the same value and will cost R 26.68 vs R 30.00/L for LPG. See what NERSA is doing here? Anything that directly competes with the Utility grid ne, priced out of the market.... Obviously the LPG price differs per region and there are similar differences for Diesel, but suffice for this demonstration to use averages to illustrate the tight control over our energy prices. Diesel is very close to half the density of LPG. Diesel gives 36 675Btu per litre (or 32 090Btu/kg) thusly you need 10.75x electricity units to match Diesel’s energy or R 21.50 worth of electricity vs Diesel cost of R 17,60/L at my last refill. So diesel based fuel heaters may work out better for Winter space heating and LPG and electricity more expensive. All of the previous will only be true, heavily depending on the relative efficiency of the heating systems. We will talk about the spanner in the works a bit later First let’s tackle water heating by other means, apart from direct resistive element heating. Normal electrical elements gives you a 1:1 ratio (or very close to 100% efficiency) for the energy input to heating output, be that for space heating or water heating. If you offload a geyser from the Utility grid, you could save a lot of electrical energy. Let’s go then…. Heating of 150 Litres of water, from 20C to 65C will take 4hours with a 2kW element, roughly then 8kWh or R 16.00. After using water for a bath or shower, you may need to heat from 40C backup up and this will need 4kWh or R8.00 and doing this twice a day means roughly R 16.00 in heating costs per day. We not accounting for heat losses here and these losses will increase costs. Direct Solar water heating is one way to save on most of the Utility costs. The actual heating of the water is free after the capital costs are accounted for. Another way to heat water is by Heat pump method, not discussed here. Another way is by changing water heating to LPG gas heater so saving on the kWh costs and shifting it to LPG Gas costs. All these alternate ways of heating your water means you require less Solar PV, and thus costs, and less Battery storage costs, making the Solar PV system more affordable. But, you still have to invest and pay for the energy to heat in some form, even for the alternate methods. Cooking can be done on alternate fuels as well. You get Solar cookers that use Sunlight, you can Braai cousin , or you can use a Gas stove. All these alternative fuels for supplying energy can be considered and used, depending on your requirements and lifestyle and need to save on the Solar PV systems costs. This could mean you can afford a smaller and less expensive system, if you offload some of the energy to other types of energy for those tasks. Always remembering, this is just a guide and only on here to be a guide, and to prompt some considerations. Consider this, anything Solar from direct heating of water to Solar PV, the cost of the actual energy is free for ever from the point of break even. Bar the maintenance costs, you do not pay anything for the actual energy! Any chemical fuel is like a drug, so is Eskom, you keep on paying…. Now for the spanner in the works….. Heatpumps. These things are amazingly efficient. Depending on the outside temperature, Heatpumps may harvest up to 3 times the Btu energy from the Air, compared to the Btu from the kWh they consume to harvest. This holds true, roughly, for the Airconditioner or water heater types. There are however the substantial up front cost to purchase the unit. Next Look into the questions and answering all 1000…. Well maybe not, YOU should answer them. A number of answers were given for these two designs already. For the rest of these we will answer some more in the following section: What goes into planning and how to do so (Fail to plan, and you surely plan to Fail)
  12. More better later, is now We continue with the models. Also, as to costs and payback and savings, all them boring Financial stuffs…. Energy flow and the typical usage for a home. In the below we can see when, on average, people use energy in comparison to when Solar energy Is generated. Above the Zero line is generation, and below it is consumption. This makes it clear why battery use is so important. The grey parts of the graph is energy consumption that cannot be satisfied by either Solar generation or battery supplied energy. This means the following, If you have only a few panels and the grey part of the graph overlaps with the yellow Solar part, you do not have enough panel. Early morning and late afternoon this is normal as the Sun is rising or setting still. During nighttime the only way to not be a net consumer (ie from the Utility grid) is to have alternate generating capacity other than Solar, or battery storage of sufficient size. Compare the barebones system to the off-grid one above to see the effect of enough Solar panels and battery capacity. These two parameters were the only changes between the two systems affecting energy flow. For Winter below, in comparison to the other seasons above, we can see that the energy usage pattern differs a lot. During Winter use, we have almost no excess energy (export) for the Barebones system and 44% less energy excess during the daytime. Here we are looking at the financial comparison. The difference is clear. Remember that Values below is actually your future savings projected to today in today’s value of your money. The blue on the flows are battery capacity being used to carry the loads above the Zero line, below the line is battery charging. Again I need to stress, this is not a systems design. You cannot use this system, any one of these two designs, to build your solution as this is far too simplistic and was only put together to ba able to this comparative modelling. It is merely done to give you the insight what to look for and how to got about YOUR planning. We will show you how to do this planning in a future post, but you need to do that planning, or pay someone to do that for you, or ask on the forum here for advice etc. You need to find the equipment brand at a suitable price to make this work for you. Also important is how you look at off-grid. You have to make a choice on a few things. Do you want to spend anything on a monthly bill? Do you want to keep the Utility grid and still consume energy from there? Are you looking for just blackout protection to ride out the Utility grid failure? All these items have a material influence on how you approach your design. For some people it's simplistic and their requirements will be different from yours or my requirements, only you know what your requirements are. There are a number of pre-packaged solutions and DIY systems out there, all of them are based on some requirements. The only thing you have to base your decision on are your requirements, so better get to know that intimately. If that is not the first thing asked, about your requirements, assumptions were made and those assumptions in your case may very well be incorrect, resulting in a system that may not be suitable to varying degrees. Next time, Alternate fuels and ways to reduce the electrical loads.
  13. Wahki, it depends on what off-grid means to you. The barebones system can supply about 3800kWh per year. That is 316kWh per month or on average 10.4kWh per day, no bad weather days, snow or cloud cover accounted for really. To be able to answer that you really need to understand when you use that energy, what your peak consumption is in kW and when this happens. It is vitally important that you also calculate accurately what appliances consume how much power and when, during daytime or after sunset. If any of the bigger loads happen after Sunset, then the battery will be too small. A lot of buts and ifs in there. You will have to start calculating and work that out in more detail I am afraid. Consider when appliances like the TV and fridge and or freezer are running with the WiFi and computer, cellphone etc. You have to account for your usage patterns and only you understand that.
  14. @Bobster, I have seen this repeated so many times, and it’s sad. We all have to pay our school fees but it is so easy to be prevented by a little forethought. Hence this series of posts. I consider it my contribution to this community. Hopefully it will help many more with some insights into how to approach Solar PV.
  15. Model the same household for off grid if the first model does not quite make off grid and see what it takes Can we go off grid now please…. Lets compare, original barebones on the left, off-grid model to the right, and no, you cannot go off-grid with the barebones system. Well not if you continue to consume the same amount of electrical energy. Upgrades done from barebones. Increased the number of Panels, changed the Inverter for a 8kW unit and added battery capacity to last for a winters night. Things to keep in mind. Panels do not face true North, panel tilt angle 20deg. I just added battery packs as if you were expanding the barebones system, but had to change the inverter to cope with the panel string voltage. If the original inverter could cope, you could leave that alone as well, so purchase a HV PV model in the first place. When designing, keep future requirements and expansion in mind. Always design for the end game, or what you believe the end game can be, that way you can prevent extra work and upgrades in future, sometimes. For both these systems, the RoI is better than most other ways to invest money (this is not financial advice as I am no financial advisor, please do your own validation). The smaller system has a better returning and lower cost of energy but the bigger system save you more and gets to reduce your monthly bill to basically R0.00 if you had a bill at all. The bigger system also makes you independent from energy price increases (funny how you never see a decrease ne), availability issues and gives you full control over your energy production and consumption. Just the annoyance factor elimination may be worth investing in Solar, any Solar. That and the energy independence is priceless. Comparing the performance from a generation and consumption perspective. With the barebones system, we not generating enough solar to cover our loads completely. There should be enough to recharge the battery and carry some of the load during daytime (and the option to charge batteries from Utility grid is there). It should cover some load shedding or blackouts rather well but. That kinda depends on how severe the blackout levels are. For the off-grid modelled system, to be able to carry all loads and recharge the battery system at 26.4kWh, we need a bit more Solar panel, in this case 20 panels. For the Summer, Fall and Spring seasons, we should have enough panel to cover for a day or a few days of overcast or rainy weather and still carry loads and recharge batteries. During Winter however, this may be challenging. Purposely, I did not optimise the panels for Winter generation bias as that will mean a non standard roof installation, and extra time and costs. Optimising the panels for Winter production in this case may just reap enough extra energy to cover battery charging back to 100% and carry all loads. That will have to be determined for each case tho. In an off-grid install, there is no feed in to any grid at all. So excess energy generation potential will go to waste, ie not generated as the system will be throttled, if not self consumed. This is where Hot water storage will benefit, as well as Heat pump Airconditioners due to their heating efficiency as well as its cooling efficiency. We can discuss why this is so for heat pumps later. Savings. This is the influence on your monthly bill for each of the 2 systems. What is the break even point for these systems? Comparison between the estimated net savings for each system and the break even time period. If your requirements are for a simple system to beat load shedding, you do not need much in terms of equipment. As is clear from the above, a relatively small investment (not these numbers or these specific equipment pieces) will get you to your requirements. If you have more of a lofty goal, you will need a bigger budget to get where you want to be. These two options used here are for illustrative purposes and should serve as a guide of what is involved. More on this financial aspect later....
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