Solar power is one of the best ways to lower your electricity bill. With the advance of technology and government incentives, more people have been able to afford solar systems.
Today we will discuss different solar batteries, which are undoubtedly a key component for a complete and efficient system even though they are not required for a solar system to work.
What are solar battery storage systems?
Solar batteries are great because they improve the system’s efficiency and store energy that can be used when there is no sun to power your system. Acting as a crucial component of a solar energy system, these innovative batteries enable homeowners and businesses to harness and utilize the sun’s abundant energy even when it is not readily available. By absorbing sunlight through solar panels composed of silicon cells, the photovoltaic system converts photons into electric current, which can either be used immediately or stored within the solar battery for later consumption.
These high-performance batteries are designed with longevity in mind, capable of efficiently storing surplus electricity over extended periods while minimizing power loss. With their ability to discharge stored energy on demand, solar batteries provide an uninterrupted power supply during cloudy days or at night when little or no sunshine is available for direct conversion into electricity.
Knowing which battery to choose can be difficult with so many options on the market. This article discusses 2 great options in the market: the Tesla Powerwall 2 and the BYD Battery Box.
Both batteries have a large capacity, and if your solar panels don’t generate at least around 15 kWh during winter, then these two batteries are not worth the investment and you should look at smaller energy storage alternatives. If your solar system is powerful enough to provide a full charge to these batteries, then keep reading to check which one might be a better option for your system.
High-voltage or low-voltage solar batteries
Firstly, here is a quick explanation for the first question you may have when you start researching solar batteries: high or low voltage.
To assess the type of battery, the process is the same as any other component: it should be determined by your energy consumption and the size of the system you plan to install.
High-voltage solar batteries have gained popularity due to their ability to deliver increased efficiency and reduced energy losses during electricity conversion processes. These advanced technologies typically operate at around 400 volts DC, enabling them to handle higher power levels with lower currents, resulting in decreased resistive losses over long cable distances. This optimal performance makes high-voltage solar battery systems particularly suitable for large-scale applications such as commercial buildings and utility-scale solar farms.
On the other hand, low-voltage solar batteries are designed with a focus on safety and ease of installation. Operating at around 48 volts DC, these systems offer a more accessible solution for residential and small-scale installations. Low-voltage technology simplifies electrical wiring requirements by reducing the risks associated with higher voltages while ensuring compatibility with standard household appliances. Additionally, these systems often incorporate modular designs that allow users to expand their storage capacity gradually.
The majority of residential solar systems are low voltage: 24V or 48V. These systems have lower electricity production and installation costs compared to high-voltage systems. Therefore, low-voltage batteries are the obvious choice for this type of system.
In this article, since our focus is residential solar systems, we’ll compare the Testa Powerwall 2 with the Battery-Box Premium LVL, the low-voltage model from BYD.
Tesla Powerwall 2
Tesla is undoubtedly one of the most technologically advanced companies in the world and a reference for technology and innovation. Even though the company’s solar division is still small, it is no surprise that they produce one of the most advanced and reliable solar batteries on the market.
The Tesla Powerwall 2 is a residential or light-commercial battery system with a storage capacity of 13.5 kWh and a continuous power output of 5 kW and 7 kW at peak times; This should be more than enough to power most large modern homes from sunset till the next sunrise. Another feature of the Powerwall is its modern and compact design. The battery is sleek and distinctive from all other batteries on the market, living up to the brand, and it can be installed on a wall mount or on the floor.
In a positive development, Tesla has recently unveiled a new purchasing option for their renowned home battery system. Breaking away from previous restrictions, where Powerwall batteries could only be purchased in conjunction with the Tesla Solar Panels and Roofs, customers can now acquire the energy storage solution independently.
Tesla Powerwall 2 Specs
| Price | ~ AU$14,000.00 |
| AC Voltage (Nominal) | 208V, 220V, 230V, 100/200V, 120/240V |
| Total Energy | 14 kWh |
| Usable Energy | 13.5 kWh |
| Real Power, max continuous | 5 kW (charge and discharge) |
| Real Power, peak (10s) | 7kW (discharge only) |
| Round Trip Efficiency | 90% |
| Warranty | 10 years at 70% |
| Dimensions | 1150 mm x 755 mm x 155 mm |
| Weight | 125 kg |
| Mounting options | Floor or wall mount |
| Operating Temperature | –20°C to 50°C |
Check the full specs here
Tesla Powerwall 2 Main features
The Powerwall 2 includes features that impress not only for the performance but also for the great flexibility and control over energy consumption.
Inbuilt inverter
The Powerwall is an AC battery with an integrated AC-DC inverter/charger. It doesn’t mean you don’t need an inverter because the Powerwall is connected to the switchboard or subboard, not the solar panels. However, the integrated inverter does make the connection and installation process much simpler, and it means that the Powerwall can be added to existing solar systems and even to a conventional electrical (non-solar) system as a backup.
Modular system
The 13.5 kWh offered by the Powerwall is considered large-capacity storage when compared to other batteries available in the market. It is not enough to go off-grid, though. The cool thing is that you can expand the system by connecting multiple Powerwalls to increase the capacity storage of your system.
Lithium-ion battery
The lithium-ion batteries used in the Powerwall are very similar to the ones used in the famous Tesla electric cars. There is no need to mention that these are some of the best batteries available in the world.
One downside is that since there is a global chip shortage and Tesla uses the same chips for their cars and the Powerwalls, the cars are their priority during this low supply period.
Liquid Cooling System
The Powerwall is the only battery in the market to use this advanced thermal management technology. The system enables the battery to operate in temperatures where any other battery could. According to Tesla, the battery can operate in temperatures from –20°C to 50°C, but the recommended temperature is from 0°C to 30°C, so it still should be installed in a sheltered location.
App and consumption mode
Like other Tesla products, the Powerall can be connected to the Tesla app, enabling you to monitor your energy consumption and manage your battery. You can choose between different controlling modes to customize how the device is charged and discharged according to your needs.
Pros
- Large storage capacity
- Scalability
- Simple installation
- advanced technology and high-performing battery
- Warranty – 10 years at 70% capacity
- Modern and compact design
Cons
- Supply shortage/delays
- More expensive
BYD – Battery-Box Premium LVL
BYD is a multinational company based in China with over 30 industrial parks worldwide. According to them, they are “a high-tech company devoted to technological innovations for a better life” and dedicated to providing zero-emission energy solutions.
BYD is one of the world’s largest producers of electric cars and lithium-ion rechargeable batteries.
In 2017, the company announced the intent to penetrate the Australian market, and the BYD B-Box product range has become some of Australia’s most popular solar batteries.
The BYD B-Boxes come in high and low-voltage models and received international awards as the batteries with the highest efficiency in the market.
The BYD – Battery-Box Premium LVL is a low-voltage and popular choice for most residential solar systems. The starter model offers 15.4 kWh capacity to be extended to 983 kWh. The modularity and scalability are impressive and make the battery suitable for residential, commercial, and even industrial projects that do not require high voltage.
BYD – Battery-Box Premium LVL Specs
| Price | ~ AU$12,000.00 |
| Number of modules | 2 |
| Voltage (Nominal) | 51.2V |
| Usable Energy | 15.36 kWh |
| Max continuous output current | 250A |
| Peak output current (5s) | 375A |
| Round Trip Efficiency | 95% |
| Warranty | 10 years at 60% |
| Dimensions | 500 mm x 575 mm x 650 mm |
| Weight | 164 kg |
| Operating Temperature | –10°C to 50°C |
| Scalability | Max. 64 in Parallel (983 kWh) |
| Battery Cell Technology | Lithium Iron Phosphate (cobalt-free) |
Check full specs here
BYD – Battery-Box Premium LVL Main Features
The BYD – B-Box Premium LVL can suit a wide range of projects thanks to its scalability. Additionally, these are other main features that make this model a popular choice:
Modular System
This is the best feature of BYD batteries. The huge scalability and the wide range of products offered by BYD cover a wide range of scenarios, requirements and industries, making them a great option for most systems.
It is possible to combine 64 B-Box Premium LVL in parallel and have a total of 983 kWh of usable energy. The massive capacity combined with the High Peak Discharge capability makes this battery system ideal for off-grid applications.
High Power Output
With a continuous output of 250A (approx 12kW) and peak output of 375A (approx 19kW), the B-Box Premium LVL can store plenty of energy to power a modern house, including potential extras such as pool heating.
Modular Lego Block Type of Energy Storage
This technology, backed by the investor Warren Buffet, is part of their patented modular design developed to optimise space and simplify installation. This means that the battery modules can be stacked like Lego and connected through a plug-and-play system that does not require any internal wiring. The B-Box Premium LVL offers the ability to stack two modules of this module.
Cobalt Free Lithium Iron Phosphate (LFP) Battery
Lithium iron phosphate chemistry is safer than traditional lithium-ion and claims to provide an extended life cycle and higher power. Similar to Tesla, BYD solar batteries are built with the same battery modules as BYD’s Electric Vehicles.
High Efficiency
With one of the highest efficiency ratios in the market, the B-Box Premium LVL can deliver a usable energy ratio of 95%, which means that very little energy is lost in the system.
Natural Cooling
Similar to the Tesla Powerwall 2 but using a different technology, the B-Box Premium LVL can operate in extreme conditions. Its natural convection cooling system allows the battery to operate from –10°C to 50°C and achieve the highest system efficiency in normal conditions, with minimal noise.
Pros
- More affordable
- Large storage capacity
- High power output
- Impressive scalability
- Simple installation
- advanced technology and high-performing battery
- Warranty – 10 years at 60%
Cons
- Bulkier when compared to the Tesla Powerwall 2
- Indoor only
Comparison Between Tesla Powerwall 2 and Byd B-Box
 Tesla Powerwall 2 |  BYD Battery-Box Premium LVL | |
|---|---|---|
| Price | ~ AU$ 14,000.00 | ~ AU$ 12,000.00 |
| Usable energy | 13.5 kWh | 15.36 kWh |
| Max continuous output current | 5kw | 250A (~12kw) |
| Peak output current | 7kw (10s) | 375 A (5s) (~19kW) |
| Round trip efficiency | 90% | 95% |
| Warranty | 10 years at 70% | 10 years at 60% |
| Dimensions | 1150 mm x 755 mm x 155 mm | 500 mm x 575 mm x 650 mm |
| Weight | 125 | 164 kg |
| Operating temperature | –20°C to 50°C | –10°C to 50°C |
| Scalability | 121.5 kWh (9 modules) | 983 kWh (64 modules) |
| Battery cell technology | lithium-ion | Lithium Iron Phosphate (cobalt-free) |
| Mounting options | Floor or wall | Floor |
| Environment | Indoor and outdoor | Indoor |
Conclusion
The Tesla Powerwall 2 is, without a doubt, a great product and stands for the brand, with a sleek design and undeniable performance and technological features.
The Tesla Powerwall 2 undeniably stands as a remarkable product, exemplifying the brand’s commitment to sleek design, impeccable performance, and cutting-edge technological features. This year’s price drop has significantly enhanced its competitiveness, making it an even more compelling option for energy storage solutions. While the Powerwall may have been relatively pricier than some competitors in the past, this price reduction enhances its affordability and shortens the payoff period for the entire system. Additionally, the company’s recent decision to reintroduce the Powerwall 2 as a standalone product makes the product a viable option for those who already have a system installed or are those who would like more flexibility to choose components based on other factors, such as price, warranties, features etc.
Despite the initial cost, customers who have invested in the Powerwall have expressed immense satisfaction, affirming that the product justifies its worth through its remarkable performance and reliability.
Meanwhile, the BYD Battery-Box Premium LVL is a great and powerful battery regarding power output and scalability. The design is not as sophisticated as the Powerwall, and the price difference is not as significant as it used to be. But the technology, efficiency and performance are advanced and some of the best in the market. BYD also has been growing rapidly and is becoming one of the leading companies in energy storage, so we can expect more development and advancements to its solar product lineup.
Before choosing your battery, remember to first evaluate and determine your energy consumption and required system size. Then you can make an informed decision and pick the best components that meet your needs and fit within your budget.
If you are looking for solar installers on the Sunshine Coast or have any questions regarding a new or existing solar system, please do not hesitate to contact us. We are more than happy to answer any questions you may have and assist you with any issues. Contact us for a free quote.
