Solar power is a sustainable and cost-efficient power source, and with the introduction of home battery backups, they are becoming much more attractive to potential buyers. They help reduce your carbon footprint while saving you money. Two of the biggest names in the game right now are the Tesla Powerwall 2.0 and the LG Chem RESU.
The LG Chem RESU has a better efficiency rating and price point, while the Tesla has a better warranty, giving it a slightly better potential value over time when it comes to long-term performance. Which one is better for you comes down to several different factors.
Overall, the Tesla Powerwall 2.0 and LG Chem RESU are similar. They are home backup batteries for solar power that will help keep you off the power grid. This method is greener, more efficient, and more affordable than traditional energy. There are many backup batteries on the market, and which is better for you depends on several different factors.
About the Tesla Powerwall 2.0
The Tesla Powerwall is in its second iteration, first coming to market in 2015. Their reputation as a leader in electric, efficient cars lent a lot of credibility to their entry into the solar energy business, and they have been innovating ever since. Their home battery system helped introduce a whole new generation to solar energy.
The Tesla Powerwall offers many features:
- It will store solar energy.
- It will detect power outages.
- It will seamlessly switch to the default power source when it is needed.
The Powerwall is a green energy source as it does not require any additional fuel to run, and even better is that it is completely rechargeable using solar energy.
You can monitor your Powerwall 2.0 using the Tesla mobile app. With it, you can see how much energy you are using, set any preferences you have to optimize your Powerwall’s performance, and control your system from anywhere. You can even install multiple units based on your home’s need – this is not a one-size-fits-all solar-powered solution!
How It Works
The Tesla Powerwall 2.0 integrates seamlessly with your Tesla and other compatible solar panels, converting solar power into energy that you can use to power your home. Once your panels are fully charged, excess energy is then sent to the Tesla Powerwall 2.0. This will then store all excess energy that you can use the next time you need it.
Any energy that you cannot use or cannot store will be sent to the power grid for others to use. When this happens, you get a credit, so it will help you the next time you need to go in the grid. You can hook up multiple Powerwalls to help you stay off the grid longer. Though, keep in mind that you need enough solar panels to power these batteries.
Ultimately, the backup battery provides peace of mind that you can have an extra source of energy that can power your home during a power outage, cloudy day, or more. The Tesla Powerwall units can safely be used during most weather conditions, and it does carry emergency shut-offs in the case of a fire or other emergency situations.
You can retrofit most solar power systems to work with the Tesla Powerwall 2.0, though you can use it even if you do not have an existing solar panel energy system. Instead, it can be used solely for backup power purposes once properly charged. This makes the Tesla Paowerwall a versatile energy system for your home backup battery needs.
Specifications
The Tesla Powerwall 2.0 uses an AC coupled battery with an integrated inverter and charger for AC to DC energy. It uses lithium cells in a lithium-ion battery, which have a greater energy density, as well as a longer battery runtime. The Powerwall 2.0 has an advanced liquid cooling system, which helps release more heat under high energy loads.
It also prevents overheating from rapid charging, which will help your battery life last longer and perform better at higher temperatures over time. It has a 13.5 kWh energy capacity. It offers 7 kW of power during peak with 5 kW continuous. When you are switching from solar power to the backup battery, it will be a seamless transition.
- The unit itself weighs about 251 pounds.
- It is 45” x 29.6” x 5.75”.
- You can have up to 10 Powerwall units working simultaneously to support your solar energy system.
- You can install it indoors or outdoors, either floor or wall mounted.
- The unit features water and dust resistance, and it can be used between temperatures of -4 and 122 degrees F.
The Tesla Powerwall meets all US and international EMI and safety standards. It also has several safety features built in to make sure that even if you are off the grid, you can easily cut the power in the case of an emergency. It also has a high fire rating. These features help promote the safety of your family in sustainable greenways.
Efficiency
The Tesla Powerwall 2.0 boasts a 90 percent efficiency, meaning that it retains 90 percent of the energy that is stored for use. That is within the industry standard and competitive amongst its peers, though others, including the LG Chem RESU, have better round-trip efficiency. With the Powerwall, you only lose 10 percent of energy during the conversion process.
What your Tesla Powerwall can backup depends on how many units you have. A single Powerwall can power lights, electrical outlets, and 120V small appliances. If you have additional units, you can also power larger appliances like air conditioners, stoves, Tesla EV Charging, electric dryers, and water heaters. The more units you have, the more you can do.
You will want to make sure to keep your Tesla Powerwall out of direct heat and sunlight. These could prohibit optimal performance and cause damage or eventual shut down to your battery. Being exposed to extreme heat and direct sunlight can lead to a decrease in efficiency for your Tesla Powerwall 2.0. This is standard with all batteries.
Warranty
The Tesla Powerwall 2.0 has one of the best warranties on the market today for home backup battery systems. Not only does it offer a 10-year warranty, which is standard for these types of batteries, it also guarantees a minimum capacity of 70 percent over its lifetime, which is a strong testament to Tesla’s confidence in its long-term performance.
That means you can expect to only lose 30 percent battery capacity in your Tesla Powerwall 2.0 over the course of 10 years. You will have the capacity to store more energy for when your solar units are no longer producing energy, either during the night, during less sunny days, or during high energy usage in your home – better than most competitors.
With the higher minimum capacity, the Tesla Powerwall 2.0 will save you more over time. It is a bigger upfront investment, but this added capacity will pay off over time, though you will want to weigh it with the lower round trip energy efficiency when deciding if the Tesla Powerwall 2.0 is for you.
Compatibility
The Tesla Powerwall 2.0 is compatible with Tesla’s solar panels and solar roofs. However, it is also compatible with other solar panel systems and inverters, including:
- SMA
- SolarEdge
- Fronius
- Enphase micro inverter
- Delta
- ABB
They are constantly evaluating the market to ensure their battery can support current solar energy needs.
Make sure to use an approved solar panel power system or inverter to ensure you do not accidentally void your warranty. While the Tesla Powerwall is compatible with a lot of the systems on the market today, it is not with all, so you do not accidentally want to damage your battery by using one of those incompatible systems.
Price
You are paying for the Tesla brand name as much as the Powerwall 2.0’s performance when you buy this home battery system. It works well, but the brand name is what brings its hefty price tag. Depending on your unit and installation, it will cost between $8,500 and $16,000. This may vary based on size, the complexity of installation, and more.
Depending on your home’s size and your average energy consumption, you may need more than one Powerwall, which would lead to higher costs. During the initial assessment, a Tesla representative will help you design a solar power and solar backup system that meets your needs and your budget based on your location and usage.
In the US, you will be eligible for tax credits on your solar energy system and the Powerwall. This may vary by state, but it does provide additional incentives for customers to switch to renewable energy sources like solar power. These credits help to offset the cost of the unit and installation and
LG Chem RESU
LG has been producing top-notch home appliances for years, so entering the solar industry felt like a logical next step. This move helped open up a new demographic of customers, and they are building on their long legacy of trusted home service with the LG Chem RESU (Residential Energy Storage Unit) home backup battery system.
The LG Chem RESU is one of the most popular backup batteries on the market today, and it is compatible with most home solar energy systems.
- It is compact in size.
- It is easy to install.
- It has many key safety features.
It also costs less to install because it is smaller than other home battery systems. The LG Chem RESU is attractive to all solar power users.
In fact, their solar panels are award-winning by many publications, including Green Builder, Architect’s Newspaper, and PV Magazine. This is only the start of why the LG Chem RESU is part of the best on the market. You will get the highest efficiency with the best value when you purchase the LG Chem RESU home battery as a backup.
Any of the LG Chem RESU home battery backups will aid in keeping you off the grid for less, though keep in mind that the LG Chem RESU 13 was made to be a direct competitor to the Tesla Powerwall 2.0 unit. One benefit of the LG Chem is you can stack multiple batteries for varying capacities to further customize your system.
How It Works
The LG Chem RESU connects with your solar panel system, storing excess energy that you can use before going on the grid. The solar panel system and home battery backup work especially well if your utility has demand charges, time-of-use rates, or reduced or removed net metering. You will be able to better control when and how you go on the grid.
The LG Chem RESU helps provide a sustained solar power solution, especially when your panels are no longer receiving any energy. This could be during the night, a power outage, or simply during a time when you are using more energy than you are capturing from your solar panels. This will be uninterrupted – you will not notice when you switch.
Once the battery is charged, excess energy will go to the grid, which you will get credit for. You will not transition to the regular power grid until you use all of the solar panel power and backup power supplies. This gives you more flexibility in your sustainable energy source and how you can minimize your carbon footprint.
Specifications
The LG Chem RESU comes in four different models that you can choose between based on your home energy needs. The LG Chem RESU uses a DC connection with a lithium-ion battery, and it is designed to integrate seamlessly as a DC-coupled system. Not all units may be available in your geographic location for residential use.
| RESU3.3 | RESUL6.5 | RESU10 | RESU13 | |
| Total Energy (kWh) | 3.3 | 6.5 | 9.8 | 13.1 |
| Usable Energy (kWh) | 2.9 | 5.9 | 8.8 | 12.4 |
| Capacity | 63 | 126 | 189 | 252 |
| Nominal Voltage | 51.8 | 51.8 | 51.8 | 51.8 |
| Voltage Range | 42.0-58.8 | 42.0-58.8 | 42.0-58.8 | 42.0-58.8 |
| Dimension | 452 x 403 x 120 | 452 x 656 x 120 | 452 x 484 x 227 | 454 x 626 x 227 |
| Weight | 31 | 52 | 75 | 99 |
All versions have an IP55 enclosure protection rating, which means they can be installed semi-outdoors with no direct exposure to sunlight or other weather conditions. It uses CAN2.0B to communicate and carries UL 1973/TUV (IEC 62619)/CE/FCC RCM certificates. The RESU13 carries a TUV(IEC 62619)/CE/FCC/RECM certificate.
The LG Chem RESU uses a polymer flat laminated battery design (PH3), which is different from other batteries. These polymer cells will provide you with higher energy density, increase reliability, and better safety methods. They carry a UL1973 fire safety certification, which shows that they are not combustible under the worst thermal conditions.
Efficiency
Hands down, the LG Chem RESU has one of the highest efficiency ratings of any home battery backup system on the market today. It has an incredible 96 percent round-trip efficiency, much higher than the industry standard of 75 to 90 percent. You only lose about four percent of energy during the conversion process, which is incredible.
That means you will be able to use almost all of the energy you are storing because you will lose less during the round trip lifespan of your energy. This will help you better control how long you can stay off the grid for your home power needs and save you money over the long term, given the solar energy rates are more cost-efficient.
- Much like the Tesla Powerwall 2.0, you will want to make sure that your LG Chem RESU is out of direct sunlight and away from any extreme heat.
- Prolonged exposure to the elements could impact your system’s efficiency, leading it to perform at lower capacity or stop working over time.
- There have been recalls on LG batteries recently for performance issues.
The efficiency of the LG Chem RESU is a great selling point of the home battery backup system. It does have some long-term degradation issues that the high-efficiency process may help to offset in terms of performance issues.
Warranty
The LG Chem RESU carries the same 10-year warranty as many other home battery backup systems. However, it only guarantees a 60 percent capacity over time, meaning that it may store less energy over time than others on the market. You will potentially see 40 percent battery degradation over time, which is significant in long-term storage.
You get 10 percent more battery degradation with the LG Chem RESU when compared to the Tesla Powerwall 2.0. However, this could be offset by the high-efficiency energy conversion rate. You will lose some energy that you store, but you initially will be storing way more than other similar backup batteries on the market.
With this in mind, it may all come out even when you compare the efficiency rating and the minimum storage performance, helping that additional degradation not feel like too much of a miss when you are looking at the LG Chem RESU. It may not store as much over time, but it produces way more initially, so decide which is more important to you.
Compatibility
The LG Chem RESU home battery systems are compatible with most off-grid and hybrid inverters. These include 48V hybrid and off-grid inverters like the SolaX Power, Ingeteam, Sungrow, Goodw SE, Solis, Selectronic SP PRO, Victron Energy, SM Sunny Island, SolarEdge, SMA, Huawei, Fronius Sumo, and Growatt, among others.
Before you choose an inverter, you will want to make sure it is on the list of approved products. If you are using an inverter that is not approved by LG, you will void their warranty. While it is compatible with most, you will want to get a professional to install it.
This installation will help to ensure that your LG Chem RESU perfectly integrates into your existing home solar power system but also that it is installed properly for safety reasons. If your system has an app, the LG Chem RESU may also be compatible with that so that you can control your system’s optimal performance no matter where you are.
Price
The LG Chem RESU is among the most affordable home battery backup solutions available today. It will cost between $6,000 and $7,000 without the cost of installation. With installation costs, you are likely looking between $9,000 and $13,000, depending on the complexity of the job. It is recommended to use a professional to install your system.
Keep in mind that there may be financial incentives for you to install a solar panel system and backup battery, so you will want to check with your state and federal regulations. You will be eligible for a tax credit at the end of the year, so make sure to submit all the paperwork to your accountant. These perks help offset the system’s cost.
Which Backup Battery Is Best for Me?
Ultimately, the Tesla Powerwall 2.0 and the LG Chem RESU are similar home battery backup systems. You will be able to use them with your new or existing solar panel systems to store solar energy for future use. Each system has its own pros and cons, and it depends on your preference which will best meet your home’s energy needs.
- The Tesla costs more upfront, but it has a better warranty with a guaranteed minimum capacity over time that will help you to store more energy over the course of your Powerwall 2.0’s lifetime.
- You will, however, lose slightly more energy during the conversion process than other home battery backup systems, including the LG Chem.
- The LG Chem is slightly more cost-efficient, and it has a better energy conversion rate, more size options, and industry-wide compatibility.
- It will likely face more battery degradation over time, and the warranty only guarantees a minimum of 60 percent capacity over 10 years, which could lead to significant long-term performance issues.
Before you get your heart set on one solution over the other, check to make sure it is available in your area and consult with professionals to see what they recommend. They can estimate the number of batteries you need to support your home’s solar energy needs and recommend which solution will best fit your needs.
Terms You Need to Know
When you are looking to buy the best home battery backup system for you, you will want to understand some key terms. This will help you choose between your options with ease because you can compare them side-by-side using the same terminology.
Efficiency
A battery’s efficiency means the amount of energy that you lose when you convert the electricity from the solar panels into stored electricity and then back again into the electricity you can use to power your home. It is called round-trip efficiency because it is the full life cycle of the energy as you capture it, store it and use it.
The industry standard ranges between 75 percent to 95 percent, which means that you could potentially lose up to 25 percent of your stored energy to conversion. The lower the number, the more efficient your home backup battery is.
AC vs. DC Power
The Tesla Powerwall 2.0 features AC power, while the LG Chem RESU features DC power. AC stands for alternating current power, while DC power is direct current, and the electrical charge will only go in one direction.
Most appliances run on AC power, so you will need to convert any DC power to AC in order to use it. You will need an inverter to do so, and there will be energy lost in the conversion process.
Warranty
The industry-standard warranty is 10 years, which is the number of years that it guarantees its performance against any naturally occurring defects. Often, these will not apply to any man-made damage. So if your battery stops working because of a hardware issue, this will be covered; but if you break it while moving, that will not.
On top of this, they also often guarantee capacity as part of the warranty. So if your battery starts to underperform over time, that too will be covered. For example, they may guarantee a 70 percent capacity over 10 years. This is a great way to know that the company stands behind its product in both the long- and short-term.
Enclosure Protection Rating
The enclosure protection rating estimates how waterproof your system is. The rating will determine if you are able to install the unit outdoors or if it should only be installed indoors or under semi-outdoor conditions. They typically come in IP67, IP66, and IP65 enclosures.
Currently, the Tesla can be installed both indoors and outdoors, while the LG Chem RESU should only be installed in the semi-outdoors for maximum performance because it carries an IP65 enclosure rating. IP65 means that the outer casing can protect against water jets without harmful effects. This has been tested over time and pressure points.
Conclusion
Both the Tesla Powerwall and the LG Chem RESU are incredible battery systems that can store energy and supply it with great performance. Deciding on the best choice for your home comes down to choosing which specifications you prioritize the most.
It is also true that Tesla’s Powerwall is far more well known than LG’s Chem RESU since Tesla broke into the solar game before LG. It is not certain which brand will come out on top in future generations of solar technology.