About solar voltage
We have not discussed batteries in detail, today we will talk about this topic.
When our solar panel starts to generate electricity, it will generate voltage. The voltage of the whole PV module will be as high as several hundred volt, and they will be sent to the inverter in the form of DC.
How should we choose the type of battery? For solar energy storage batteries, it can be divided into high voltage and low voltage.
What’s the difference between low and high voltage battery?
In this article, you will get:
1, The concept of high voltage battery and low voltage battery
2, Advantages and disadvantages between high voltage and low voltage
3, Case pictures of installation
Low voltage battery:
Low voltage battery have a relatively low voltage. For example, the Nominal Voltage of ARK LV Battery is usually in the 51.2v, and the Operating voltage Range is 47.2 to 56.8V.
Cons:
Low voltage batteries normally discharge slower, it is difficult to cover start-up, requiring additional power from the grid for instant power or high powerful appliance. Therefore, an information shows that high power load needs extra grid power plus PV or plus battery together.
Pros:
Great for getting started with owning battery systems even if only one module.
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Besides, Low voltage battery are linked together in parallel to increase the current and to keep the voltage constant (although the overall voltage of the batteries needs to be compatible with the inverter). According to Ohm’s law ‘I=U/R’ , the smaller the resistance in parallel, the higher the current. One of the benefits of increasing the current is that it can run continuously without exceeding temperature limits, so that the best charging time will be achieved without the need for cooling down frequently.
Better for off grid system:
Low voltage batteries are very suitable for Off Grid Solar System, such as SPF 5000 ES Growatt, which are very compatible with ARK LV batteries, because low voltage batteries are designed to be deeply cycled and can provide stable power, rather than short-term, fast-providing high kinetic energy like car batteries. In Australia, currently only the low voltage version of the off-grid inverter is approved, which is matched with a low voltage battery.
They follow several factors:
· Safety
· easy maintenance
· initial cost and total life cycle cost
· battery temperature
· discharge depth
· charging control capability and function settings.
In addition, off-grid mainly relies on PV module or batteries size. If the weather conditions are not good, then you have to rely mainly on batteries, so the number of batteries must be large. It is recommended to add at least 20-30% of solar panels and batteries for any off-grid solar system.
A Low voltage battery case installed recently:
The current of the low voltage battery is very large, so in the actual installation process. At this time, you need a current protector to avoid overload. BDM-125 is equivalent to a switch, the function of overload protection and short circuit protection. It is roughly divided into 125A, 160A, 250A.
High voltage battery:
High voltage batteries, as the name implies, have relatively high voltages, usually in the hundreds of volts.
For example, ARK XH Battery System – Growatt have the nominal voltage 360～440v, and the operating voltage range is between 360V-550V to 440V-550V. They are usually connected in series connected with the stacked layers higher and higher.
Advantages:
High voltage battery can provide a higher discharge rate, which can support high power loads, and can meet the fast response of startup.
Compared with other battery systems, it has better charging and discharging performance, higher charging and discharging efficiency, more accurate status monitor, longer cycle life and less self-discharge loss.
High voltage batteries are ideal for homes or commercial properties with particularly high energy demands. As said above, if you are looking for fast charging and discharging batteries, high voltage batteries are right choice for you.
Disadvantages:
High voltage battery requires at least two modules to get enough voltage, so the initial investment will be higher than the cost of low voltage battery.
Besides, high voltage battery needs to know the maximum charging voltage to avoid overcharging. So we need BMS (Battery Management System) like the BDC box added on the top.
They also need to be compatible with the high-voltage version of the inverter to convert it into 240v/50hz AC power for the load.
Welcome to contact us getting a free quote for your first home battery system
In conclusion, everything depends on your requirements of using electricity.
