Ultimate Tesla Powerwall Review

As the cost of conventional sources of power keeps going up on a regular basis, there certainly is a need for alternate sources of power. Apart from cost, there are also a few other reasons for the growing demand for alternate power sources like solar power. It is clean, green and most important it is a renewable source of energy. Though the initial investment in setting up the infrastructure for solar energy may be a big on the higher side, the recurring expenses and the energy cost savings that it offers will more than make up for the initial cost. Hence, it is quite obvious that there is a growing demand for solar based energy supply.

However, there are a few things that must be kept in mind while choosing solar energy as a source of power. There should be avenues to store the power that is generated with the help of solar panels and other infrastructure. In most homes, solar power is used as a backup source of energy and also for storing power so that it can be used when it is needed. To make this possible, there is a need for a quality, powerful and reliable battery storage system. In this article we will be looking at one such lithium battery system that may be able to change the ways solar energy is used across the world. It also could redefine home energy storage and ensure that it is pushed into the mainstream.

The Fascinating World of Powerwall

The product that we will be reviewing is the Tesla Powerwall battery system. This is a popular and much sought-after product from Tesla Energy. It has been able to create quite a bit of excitement amongst thousands of homeowners who are looking to store power from solar energy and make use of it when it is needed. The battery storage that we are going to review and talk about, also could help store power from the main grid. This also could be used later whenever there are power outages caused by natural disasters or even because of technical faults and other such reasons. We hope that this post will be useful for the readers and other interested persons to have a better understanding of lithium battery-based power storage systems. It may help them to compare Tesla Powerwall with other such options and buy the best one based on quality, reliability and of course their personal needs and requirements.

A brief History about Tesla Powerwall

It would be pertinent to mention here that the first Powerwall lithium battery storage system was released into the market roughly about 6 years ago. The initial capacity was around 6.4 kWh and it had a high voltage coupled battery running on DC. However, the company has been able to upgrade its technology and the new Powerwall from Tesla comes with more than two times the storage capacity. The icing on the cake is that it is available at an equivalent price. You also get an inbuilt charger and inverter. Hence, many customers are of the opinions that it offers them reasonably good value for money.

The new model of Powerwall has seen an upward revision in price in 2018 and the price rise has been to the tune of 30% when compared to the first model released six years back. However, this price rise has to be looked at from the background of increased power storage capacity. The storage capacity stands increased from 6.4 kWh to double that capacity. Hence when the increased price is calculated by taking into account the kWh power available, the rates are still highly competitive and almost 30% less than the first model. Hence, there are reasons to believe that Tesla has been able to offer the best value for money to its customers.

What are the Features of Tesla Powerwall?

Let us have a look at the current specifications of the Tesla Powerwall.

Main features

  • Comes with a usable capacity of 13.5 kWh and a depth discharge of 100%.
  • Integrated inverter with AC battery.
  • Offers a 5kW power output and 7 Kw maximum output.
  • Also has a cooling system that is liquid in technology.
  • Comes with a 10 years warranty ensuring a retained capacity of around 70%.
  • Price tag of around $10,000 with an additional $1700 for backup gateway.
  • AC Voltage 120/240 V Nominal
  • Split Phase Feed-in Type
  • 60 Hz Grid Frequency
  • 10 kA Maximum Supply Fault Current
  • 32A Maximum Output Fault Current
  • 30A Overcurrent Protection Facility
  • +/- 1.0 adjustment possible as far as power factor output range is concerned.
  • 50V Internal Battery
  • 90% Round Trip Efficiency.

What makes These Batteries Different?

The Tesla Powerwall is considered quite different from most other such options because of the special cells that are used. Tesla uses NMC for making these battery cells. They are manufactured with Panasonic as their partners. The cells are almost the same as cells that are seen in the electric vehicles of Tesla. However, it should be noted that larger sized lithium cells – 2170 are the ones that power these battery devices.

What Makes Powerwall2 More Popular?

Powerwall2 is the latest version of and has quite a bit of improvement of Powerwall1. The new model has been designed to make it more compact. Further it is easy to install and handling is also easier. The attractive curves that were part of Powerwall, have been replaced with a rectangular shape that is considered to be more practical. It comes with venting on both sides and they help a lot in keeping the unit cool. Further, a bright and LED strip (green in color) also has been included. The on and off switch is quite simple.

The weight of the unit is 120 kg and of course it is not light. However, because of the new design features it is easy to handle the battery. Further, it has facilities both for wall mounting and ground mounting. It also has an IP rating of 56 (weather rating). However, in spite of a high IP rating, experts suggest that the unit should be installed in a location that protects it from rain, sun and other elements of nature. It should be kept away from direct sunlight because it is a known fact that batteries and too much sunlight are not recommended.

Comes With Inverter

It comes with a Powerwall AC battery. In other words it has both AC-DC functions as far as the inverter is concerned and also a charger. This does have quite a few advantages as well as disadvantages. Because of the inclusion of an inverter and charger, it is possible to make use of the battery for retro-fitting with solar installations that are already in place.

Power of the Inverter

The power that is generated by the inverter is quite reasonable. You can expect a continuous and uninterrupted output of roughly around 5kW, while the peak output could reach 7kW. This compares exceedingly well with the initial model of Powerwall and also many other competitors’ models that are available in the market today. However, we need to bear in mind that peak power rating of 7kW can be maintained only for around 10 seconds. It could be suitable for those who are looking for brief bouts of power. There are some who believe that such high peak ratings may not have been designed keeping in mind the needs and requirements of home installations that required off grid solutions that are modern.

It is Liquid Cooled

One of the main reasons why Powerwall continues to catch the attention and interest of users is because of a few obvious reasons. This is perhaps the only system in the market to work on the unique liquid cooling technology. This indeed is a big takeaway because it helps the Powerwall battery to operate in a range of temperatures. The temperatures could range from around minus twenty to plus forty degree Centigrade. However, we need to bear in mind that at temperatures over +40 degree centigrade, power de-rating will come down. In other words the output may come down at such high temperatures. We need to bear in mind that this kind of derating is not uncommon and it happens with almost all batteries that are lithium-ion based. However, this problem can be overcome with the use of multiple powerwalls.

It Can Cater to Larger Capacity Requirements

If you need larger capacity, Powerwall can offer you a suitable solution. You can set it up with the help of 3 phase installation. This will however require a total of around nine modules of batteries so that they can be joined together making a single series. But this also would require additional gateway and this will certainly push up the cost by a few thousands of dollars.

Backup Gateway

We need to also bear in mind that Powerwall 2 needs a backup gateway in case you are looking for a suitable backup. This will come in handy whenever there is a power outage because of various reasons. As mentioned above the backup gateway is priced approximately at $1800 and it certainly is a great investment. It works as an efficient system as far as management of energy is concerned and also doubles up as a communication hub.

Whenever a power outage or blackout happens, the unit gets isolated from the circuits that help backups and it happens from the electricity grid system. It helps to run the entire device and also ensure that it works efficiently on an off-grid mode. You can enjoy power in your home when the whole neighborhood perhaps could be plunged in darkness. Further, the gateway is also quite advanced and sophisticated and comes with a number time-based and monitoring controls and options. However, the readers must bear in mind that it is not designed to work as an off-grid power supply system that is independent. The battery will get depleted and needs to be recharged through the solar panel.

The new Gateway that is part of the latest model of Tesla Powerwall has some noteworthy improvements. There have been improvements in speeds because of the 4G communications that are being used. Further, they also have 3-phase operation and this goes a long way in ensuring greater control. CT monitoring is also more accurate. All these improvements have been made possible even though the overall size of the gateway is smaller by around thirty percent and in terms of weight also it is significantly lower. Hence, there are reasons to believe that the new gateway has come out with quite a few other interesting and useful improvements.

Reasons Why It Could Be Good Investment

Here are some main advantages that may go in making Tesla Powerwall a good investment.

  • It is modern and compact

It comes with a minimalist design and the entire installation process is quite easy and simple. It not only provides a stable and reliable power supply source but also helps to complement the overall look and feel of the house. It easily merges with the aesthetics of the home. It is a compact, single piece solution unlike many other battery backed power systems that are clumsy and large.

  • It is Flexible and Versatile

It is one of the few units that offers the facility and flexibility of adding stack units at any given point in time. It is capable of joining two floor mounted units. This can be done in a front and back order and the installation process is not very difficult.

  • It Is Capable Of Powering Almost Everything

Powerwall is capable of reducing the dependence on the grid. This is done by storing the solar energy for use later when the sun perhaps is not shining at its best. It also allows the users the flexibility of using Powerball alone or in combination with other products from the house of Tesla. This helps in saving money, reduces the overall carbon footprint and goes a long way in preventing your home from outages and other such situations.

Hence, you can be sure that you will be able to enjoy high quality power even when you find that most of the neighborhood is running without power. This facility certainly comes in handy during natural emergencies like floods, earthquakes, storms and other such events. It reduces the dependency on the grid to quite some extent though it can never be complete and unconditional.

  • Offers Complete Backup Protection

We all know that Powerwall is an extremely efficient and proven device that is capable of storing energy. At the same time it also is capable of detecting outages and therefore it automatically turns into the main energy source in such an event. It is invaluable especially when the grid stops functioning for any reason whatsoever. This certainly is a big improvement for those homes that so far have been dependent on gasoline generators, and other such sources of alternate power.

It helps to keep the lights as well as phones charged without the need for regular upkeep. It also is completely noiseless and this compares extremely well with generators that make a big noise and are also not environment-friendly. All you need to do is pair the battery with solar and ensure that it is recharged when sunlight is available. It will ensure that all your important appliances keep running for days at length. We have heard about the old proverb that says “Make Hay While the Sun shines.” There is no doubt that the Powerball battery is a live example of this proverb in more ways than one.

  • May Help In Reducing Electric Bills

You could switch over to Tesla Powerwall and make use of the power that is stored in the battery. This can help in reducing electric bills significantly, especially when the electricity slab rates are high during a particular period of the day. Hence, you can enjoy reduced electricity bills, clean energy for your home and all this can be achieved by recharging the powerful Tesla Powerwall battery using the solar panels when the sun is shining.

  • Clean Energy

This certainly is a big advantage when you decide to go in for Tesla Powerball. Solar energy is one of the cleanest and greenest forms of energy apart from being renewable.

However, there are some downsides that cannot be ignored. Let us have a look at a few of them.

  • Upfront cost could be an inhibiting factor. Yes the initial investment that is required for buying the Tesla Powerwall battery is quite high. Further you also need to invest a few thousands in a backup gateway. In case you do not have solar panels and other infrastructure, your initial costs will go up by a few thousand dollars more. Many people may have to depend on banks and financial institutions for financing the initial investment. However, the recurring costs of the battery are not very high and it also is quite durable and long lasting.
  • It requires space. While there is no doubt that the Tesla Powerwall battery is compact and not too heavy, you need space for installing the solar panels and other infrastructure. This may not be possible in a small home where space is a luxury and constraint.
  • Choosing the right solar panel may make all the difference. Even the best of solar batteries will not be able to produce the right results unless the solar panels are able to absorb and transmit enough power to the battery for storage. This is a point that should be kept in mind while investing in the Tesla Powerwall battery system.

However, on the whole when we take into account the various pros, cons, features and customer feedbacks, it is quite obvious that the advantages far overweigh the disadvantages. Therefore, in case you are keen on staying safe when there is a power outage caused by grid failure or if you want to make use of environment friendly solar power, it makes sense to invest in Tesla Powerwall.

Are There Are Any Competitors to Tesla Powerball?

Like all products and services, Tesla Powerball also has some competitors and we will be looking at three of them.

Sonnen Battery

This is a German battery and has been in the market since 2017. Sonnen Battery has come out with the latest product Sonnen Eco and it is available in various sizes ranging from 5 kWh to 20 kWh. It is considered to be one of the most economical solar panel compatible batteries in the world. But its reliability in case of grid power outages is still not clear and therefore not many people are totally in favor of it. The smallest battery costs around $9,000 apart from installation. It may not be too cost effective in the long run.

LG Chem RESU Battery

This could be a direct competition to Tesla Powerwall because it is a lithium ion battery. However, the storage capacity is much lesser when compared to Powerwall and therefore may not be suitable for those who have reasonably high storage requirements. The larger sized home battery has a capacity of 12.4 KwH. However, this should be looked at from the cost perspective. Against an initial cost of around $10,000 for Tesla Powerwall, the LG Chem costs anywhere between $11,000 to $13,000 and this depends on the installation charges and the location where it is being installed. It may not be suitable for those who are looking to off the grid for long periods of time. They could help in homes where energy cost is a concern. The system can take care of hours of power requirement and may not be suitable for those who are looking at days of uninterrupted power supply.

BYD B-Box Solar Battery System

This is a product from a Chinese company that has its headquarter in Shenzhen. Though they may not be well-known outside China and a few other neighboring countries. The 2.5 kW battery packs are good enough for any home. However, most homes would need four such batteries. The product is available in four different capacities. The battery costs are lower compared to most brands including Tesla Powerball. However, it leaves behind a large carbon footprint and that makes it environmentally very harmful. It may not be suitable for extreme climates. Though the initial cost is much lower when compared to many other brands, the overall durability and longevity is very much under a cloud.


Choosing the right backup battery for your solar panel is not easy. This is because most people hardly have any knowledge about it and secondly, there are dozens of such brands and makes available in the market. The only way to buy the right backup battery is based on research, knowledge, due diligence process and feedback from customers. When we look at all the above factors and then come to a conclusion, there are quite a few reasons to believe that going in for Tesla Powerwall could be the right choice. It is proven and has a good track record. It comes from the house of Tesla who has an impressive track record when it comes to electric cars that run on battery backup devices.

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