Whether you're look for a battery pack for your home, business or electric vehicle, this new battery technology is what you want. With a much lower depth of discharge and a longer life span (approximately 15 years), this is the smart choice in batteries. Freedom Won Lite Home The Freedom Lite Home range covers the varying needs of homeowners and even small business premises with models ranging from the Freedom Lite Home 5/4 to the largest 30/21. These models are wall mounted offering the ultimate in space saving. The product offering increases in size through the business, commercial and industrial ranges. All models are integrated with the necessary Battery Management System (BMS) and control circuitry to protect the pack and interface with the separately supplied external inverter/charger unit – lithium cells cannot be operated without a BMS. The standard home enclosure is powder coated with white sides and face to address safety and aesthetic concerns. Energy Storage FactsLithium Iron Phosphate (Lite Home) batteries have several advantages over conventional lead-acid batteries:High energy density: more energy with less weight High charge currents (shortens the charge period) High discharge currents (enabling, for example, electrical cooking on a small battery bank) Long battery life (up to six times the battery life of a conventional battery) High efficiency between charging and discharging (very little energy loss due to heat development) Higher continuous power available RUGGED A lead-acid battery can fail prematurely due to sulphation if it is left partially charged, fully discharged, or rarely fully charged for long periods of time. A Lithium Iron Phosphate battery does not need to be fully charged, has a wide operating temperature range and excellent cycling performance. They are, therefore, the battery for very demanding applications. EFFICIENT The typical energy efficiency (energy that can be taken out of the battery compared to the energy required to re-charge) for lead-acid batteries is ~ 70%. For a LifePO4 battery, it is ~ 92%. The final 20% charge for a lead-acid battery is particularly inefficient with efficiencies of ~ 50% and can take a very long time for the battery to be completely charged. In contrast, a LifePO4 battery can achieve 98% efficiency and so can be fully charged more quickly and energy efficiently. SIZE & WEIGHT LifePO4 batteries save up to 70% in space and 70% in weight compared to lead-acid alternatives. COST EFFICIENT Lithium Iron Phosphate batteries are not more expensive than lead-acid options. The purchase price may be 10-50% more initially but this is compensated by longer life, size or weight considerations, superior reliability & efficiency. For example, a 100kWh Freedom Lite costs only 20% more than an equivalent properly sized lead-acid battery. BATTERY MANAGEMENT SYSTEM t is vital that the correct battery management system (BMS) is used to control the battery charging, in order to actively balance the individual cells that make up the battery and prevent under or overvoltage, which can otherwise destroy the battery. Freedom Won utilizes the world’s leading BMS offering superior safety, reliability and performance.
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ExSolar has been busy! Load shedding came like a unwanted visitor and surprised us all. While we had a tough time keeping up with the huge influx of solar enquiries, we got some more awesome sites finished and commissioned.
Thank you to all our customers for being so patient with us during that busy time. We know load shedding is bound to strike again, so be prepared before the demand skyrockets again, get a quote today and let's work with you to get load shedding ready! If you use VictronConnect, we have noticed some people assume you need an internet connection to update compatible products. To reassure those that have asked about this – it is not the case and here is why. All firmware files are already bundled with the app, so as long as you have the latest version of the app – you have the latest firmware. In other words, let’s assume you have not visited an installation for some time and that location does not have internet access on-site. As long as you ensure you have the latest version of the app whilst still in range of an internet connection, you can then go to site and if a product needs updating VictronConnect will tell you that. This applies to Wired and Bluetooth products (be they Smart tech built in or if using the VE.Direct Bluetooth Smart dongle).
Note: if for some unlikely reason you have any issues updating your firmware using VictronConnect, it can usually be resolved by following the steps in the firmware update and troubleshooting section of the VictronConnect manual, or by contacting your distributor.
Article courtesy of John Rushworth at Victron Energy Life used to be so simple; in a 12V battery system you took a ‘12V’ solar module, watched carefully that the maximum PV current would not exceed the charge controller maximum current and the system would work. Unfortunately due to the fact, that with PWM controllers the PV module is not feeding the battery from its maximum power point (MPP), the system loses a lot of energy. In the following diagram you can see, the area of the MPP in blue (Vmpp * Impp) is up to 30% larger than the PWM area (Vbatt * ~Isc) within the IV curve. So, with the advent of the newer Victron Energy Blue Solar MPPTs, things changed for the better when compared to PWM solar charge controllers.
Sizing the system can be done electrically to see if the system is allowed and will not destroy any components, when looking at the yield to see how much energy it will produce. For now I will look at the first part, to find out what is possible on the electrical side. By adding a DC/DC converter in the Blue Solar MPPT controller, the system also becomes more flexible when we look at the input voltage of the controller. The challenge now, is to match the PV modules to the controller, because we are not concentrating on only ‘12V’ or ‘24V’ modules anymore. Basically any module can now be used if it is within the input voltage range of the charge controller. In fact we can now put modules in series as well as parallel, which will also increase the input power and flexibility. Thanks to the output power or current limiter, the output power will never exceed the maximum of the controller. This Blue Solar MPPT feature is unique and makes the charge controller even more interesting! You can now for example add the same type of modules in parallel later without the need to change the MPPT charge controller. This reduces costs to a minimum, whilst still increasing the yield! Also, I took the values for all our Blue Solar MPPT charge controllers and Blue Solar modules and combined them into a Spreadsheet. Now sizing a Blue Solar MPPT charge controller is easy! Download: VE-MPPT-Calc.xlsx (744KB) – This configuration spreadsheet is compatible with MS Excel. Now for the technical explanation, for those who would like to know some more details: Exceeding the input voltage range will (as it did with the PWM controllers) damage the controller permanently. Of course we will also need to take a look at the minimum voltage, where the Blue Solar MPPT controller will start working. If you take a SPM50-12, the Open Circuit Voltage (Voc) is 22.2V and the maximum power voltage (Vmpp) is 18V at Standard Test Conditions (STC) which means 1.000W/m² irradiation, 25°C cell temperature and an Airmass of 1.5. If the cell temperature is higher or less than 25°C, this voltage reduces or increases due to the temperature coefficient, in this case -0.34%/°C (see Blue Solar module datasheet). So if you take 3 modules SPM50-12 on a Blue Solar MPPT 150/70 in a 48V system on cold days say, -10°C (only looking at the voltage), you can start up charging: The startup voltage is 48V + 7V (see MPPT 150/70 datasheet) = 55V The modules will produce 3 * ( 22.2V + (-0.34% of 22.2V * -35°C temperature difference)) = 74.5V 74.5V is higher than 55V -> that’s perfect Also running in the MPP the system would work: The running voltage is 48V + 2V (see MPPT 150/70 datasheet) = 50V The modules will produce 3 * ( 18V + (-0.34% of 22.2V * -35°C temperature difference)) = 61.9V 61.9V is higher than 50V -> that’s perfect Doing the same thing, when the modules get warm during the day, in this case 70°C you can see what happens: The startup voltage is still 48V + 7V (see MPPT 150/70 datasheet) = 55V The modules will produce 3 * ( 22.2V + (-0.34% of 22.2V * 45°C temperature difference)) = 56.4V 56.4V is higher than 55V -> that would work But now in the MPP the module voltage is lower than the minimum: The running voltage is 48V + 2V (see MPPT 150/70 datasheet) = 50V The modules will produce 3 * ( 18V + (-0.34% of 22.2V * 45°C temperature difference)) = 43.8V 43.8V is lower than 50V -> this is not enough! The high DC/DC conversion efficiency (97.5% at 48V) will result in following output maximum charging current (@ -10°C) of 61.9V Vmpp* 2.74A Impp / 48V Battery voltage * 0.975 Efficiency = 3.45A This is far below the maximum of 70A, so it will be all used to charge the battery. Increasing the number of modules per string to 6 in series and making 10 strings in parallel gives the following result at -10°C: The Voc will remain under the maximum of 150V at -10°C Now at high temperatures such as a 70°C cell temperature the system will work just fine! Taking this example in the Spreadsheet you can now increase the number of strings in parallel and you will see, if starting at 11 strings, that the controller will start to reduce power. The big advantage in doing this is that you will now produce the maximum controller output at a lower irradiation. As module prices decrease, this is an effective option.
Please note, that you can use ‘preconfigured’ minimum and maximum temperatures. I’ve also given some installation examples, at the bottom of the spreadsheet, with their anticipated module temperatures for various types of installations. Oversizing a PV arrayOversizing a PV array is installing more peak power (Wp) than the maximum charge power of the chosen MPPT charge controller. A common reason to oversize is to cater for winter time. How to determine by how much you can oversize a PV array? This can be done with help from the spreadsheet tool. Here though is the manual explanation of how it is done. There are two limits, when determining the maximum array size that can be connected to an MPPT:
Note that these two maximum ratings must not be multiplied to determine the maximum installable peak power. Instead, each of them needs to checked by itself: Determining the maximum PV open circuit voltageFirst look at the datasheets of the solar panels to see what their maximum open circuit voltage is. Then multiply that by the number of panels that are in series in the array. The result of the multiplication must not be higher than the Maximum PV open circuit voltage as listed on the MPPT Datasheet. Make sure to take into account the coldest expected temperature. The colder it is, the higher the open circuit voltage on a PV array will be. Determining the maximum PV short circuit currentGet the maximum PV short circuit current from the PV Panel datasheet. Multiply by the number of panels in parallel in the array. Having more panels in series does not change the number. The result of the calculation may not exceed the Max PV short circuit current as specified in the MPPT Datasheet. Good luck and enjoy sizing the BlueSolar MPPT Charge Controller! Article courtesy of Victron Energy Victron Energy have released version 2.23 of Venus OS – the software which is at the heart of the Color Control GX, Venus GX, Octo GX and the CANvu GX. A nice page outlining those products and comparing them is available here. They have also released VE.Bus version 455, for the MultiGrid and MultiPlus-II inverter/charger models.
Included in this update are various improvements; including that the user interface will not show details of VE.Bus Error 11. VE.Bus Error 11 This error only applies to the MultiGrid and MultiPlus-II models: the inverter/chargers with a dual backfeed relay. For ESS systems, a grid-code is selected in VEConfigure, and then as part of grid-code compliance; the device verifies that its internal relays and measurement circuitry functions properly. When this test fails; Error 11 shows. Quite often, the error can be tracked down to an installation error (swapped Phase and Neutral wiring for example), but there were also some software issues; and the details of Error 11 not being visible was not helping. Today we are taking care of all that. A short list of related firmware releases:
Conclusion: if you have a VE.Bus Error 11 and have already double-checked the wiring, then update all to the firmware released today; which is likely to solve the issue. And if it doesn’t – then at least you will have far more information to help you resolve it. Full changelog General:
For those who were hoping to find the Marine MFD chartplotter integration, as explained here in a blog, I have to disappoint you, it’s not ready yet; so not in this release. We can report good progress on that project though; and I still expect to release it at the end of this quarter for Navico and Garmin. As mentioned during the announcement, Raymarine will follow a bit later. How to update? You can find information about how to install the new version of Venus OS here. For the full changelog, visit Victron Professional. Article courtesy of Matthjis Vader at Victron Energy |
AuthorsMarketing Manager for ExSolar Solar Solutions Archives
May 2024
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