Tesla Powerwall 2 Charging Time Guide

Tesla Powerwall 2 Charging Time Guide

Tesla’s Powerwall 2 is a device that stores energy to be used later in the home and is attractive because of its timing methods. It can be used with or without solar energy to deliver financial savings on electric bills. However, there are stipulations to using a Powerwall 2 with and without solar, even with timed charging.

A Powerwall 2 saves owners money by storing energy during off-peak hours, which are when energy is in low demand and is least expensive. It can store energy during peak hours when energy demand is high, but this will be more costly. Read on to figure out how the Powerwall charging time with and without solar and whether it will meet your home’s needs.

Timing a Powerwall 2 with Solar Energy

Tesla’s Powerwall allows you to store energy to use later more efficiently because of the timing in which it charges for later use. If you are using it with solar panels, the Powerwall is charged during the day when the sun is using solar to power your home. The day is usually when solar panels are producing more electricity than a home needs.

The Powerwall will store energy during the day and hold it until your family is ready to use it.

  • For example, when the sun goes down, your solar panels are no longer producing electricity.
  • This would be the ideal time to use the energy stored in the Powerwall.
  • You would also benefit from having the energy stored in the Powerwall during a power outage or blackout.

Using a Powerwall with solar energy ensures you have a sequence of clean, renewable energy powering your home. But, you can still use a Powerwall without solar and save money on electric bills. This is because the Powerwall charges when your electricity costs are low and discharges when costs are high for electric consumption savings.

You more than likely purchased solar panels because you live in an area that has sufficient sunlight to power your home. These peak hours are ideal for having your Powerwall store energy for later use. You can charge your Powerwall 2 during off-peak hours, but this will be more expensive because you are using off-peak electricity.

Benefits of Time-Based Control and Solar Power

There are pros and cons when using this device with solar panels and without, and you should check your electric bill to make sure the time-based charging will be worth the expense of the device. If so, you can reduce your power bills by charging your home during off-peak hours, saving extra power for later, and saving money on bills over time.

The Powerwall 2 is constantly running an energy forecast, which means it can study your household’s energy use patterns and then optimize your family’s energy usage. Since individuals usually use the most energy at a high-peak, high-cost time of the day, the Powerwall 2 will charge during low-cost hours and discharge during high-cost hours.

There are two versions of this time-based control mode:

  • The balanced version, which is only offered with solar power
  • The cost-savings version for solar or non-solar customers

The balanced version charges the Powerwall 2 using excess solar during off-peak and shoulder hours to maximize savings and then discharges at high-peak.

The Tesla Powerwall 2 can be a lucrative rechargeable device to power your home during the more expensive peak times, at night, and during power outages. During power outages, the solar panels can continue to charge the Powerwall. But, you need to make sure you have enough panels to fully charge the 13.5 kilowatt-hours each day.

Timing a Powerwall 2 without Solar Energy

You can also benefit from a Powerwall during a power outage, even if you do not have solar energy. The device provides a smooth transition to its backup power by detecting when grid outages occur and then automatically converting to your house’s main power source during the outage. 

Another thing to keep in mind if using the Powerwall 2 without solar is the stipulations with Tesla’s 10-year warranty. If you are charging your Powerwall 2 100 percent by solar power, it will be unlimited in both cycles and kilowatt-hours. However, if you ever charge it with anything else other than solar, the warranty changes:

  • The warranty will last 10 years for the Powerwall 2, or
  • 37,800 stored kilowatt-hours in lieu of unlimited kilowatt-hours with solar power.

If you want to make sure your Tesla Powerwall 2 warranty is unlimited, the only way to do this is by powering the device with solar power. However, it can be very expensive to install both solar panels and the Tesla Powerwall 2 battery, running thousands upon thousands of dollars. It may not pay for itself when the warranty runs out in ten years.

The term “large” is key here because when you are timing the charging of your Powerwall 2, you need to understand its 13.5 kilowatt-hours of storage capacity that needs to be charged. The original Powerwall had a 7-kilowatt-hour storage capacity, but not many homes need the larger amount or generate power to fully charge the Powerwall 2.

Solar versus Non-solar for Adequate Charge

The time-based control system in the Powerwall 2 is attractive for solar-based homes, but it is not always ideal for smaller solar systems or homes that simply do not generate enough power to charge a Powerwall that huge. This 13.5 kilowatt-hours storage capacity is probably more than an average home needs to power up the house.

If you have solar panels that will be powering the Powerwall 2, you need to make sure you have enough panels on your roof to even be able to fully charge the system. If not, you may never use the Powerwall 2 to its full capacity. This defeats the purpose because you will end up not having the savings of each warranted kilowatt-hour.

  • More energy has to be put into the batteries of the Powerwall 2 than taken out, so you will need more than 13.5 kilowatt-hours to fully charge the device.
  • If you know your household regularly uses at least 12 kilowatt-hours of electricity overnight and a sufficient amount of extra electricity to fully charge the system during the day.

In order to fully charge the Powerwall 2 with solar, you will probably need five or more kilowatts of solar panels during the day. If not, you may have more savings just installing a larger rooftop solar system since you probably need more than 15 kilowatt-hours to fully charge a new Powerwall 2 to its fullest capacity of 13.5 kilowatt-hours.

Know How Much Energy Your Home Consumes

You can review your electric bill to see if you average more per day than the capacity of the Powerwall 2: 13.5 kilowatt-hours. If your home averages more than that number, the Powerwall 2 and its time-based system will more than likely save you money over time. You will probably save the most if your home averages more than 15 kWh a day.  

If you are using solar panels, the Powerwall 2 will store the 13.5 kilowatt hours to run your major appliances for a full day. The solar panels will absorb the sunlight to create DC electricity, which is then converted to AC electricity through an inverter. The energy is either used or stored in the Powerwall 2 and is managed through a cloud-based app.

  • Balanced mode prioritizes its use of stored solar power to power the home when electricity is expensive.
  • Balanced mode powers the home from its battery after the sun goes down and is not powering the solar panels.
  • Cost-saving mode optimizes the storage and usage of electricity.
  • Balanced mode minimizes the home’s usage profile to keep the electric bill costs down.

If you are using a Tesla Powerwall 2 without solar panels, it will probably be able to power a home for around twelve hours if the home consumes around 28 kilowatt-hours per day. You will need three Powerwall 2 devices to run a home for a full day without using solar panels. Two devices will power a home for eighteen hours without solar.

Solar Discounts:


The articles here on ThatTeslaChannel.com are created by Greg, a Tesla vehicle and Tesla solar expert with nearly half a decade of hands-on experience. The information on this site is fact-checked and tested in-person to ensure the best possible level of accuracy.

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