What are The Best Home Battery Storage Systems?

Enjoying partial or full-energy independence can be a game-changer for homes looking to ensure power 24/7. Nowadays, home battery storage systems have become necessary to achieve this goal and ensure uninterrupted power for the whole family. These storage systems deliver enough energy to power lighting, electronics, and many household appliances.

When coupled with photovoltaic (PV) modules, these storage systems work as solar batteries or solar battery backup systems. Home battery systems can also be coupled with wind turbines or hybrid systems (solar + wind) to achieve more ecologically friendly energy when compared with the one generated with fossil fuels.

A home backup battery bank is suitable for both fully grid-powered homes and homes with renewable energy-generation systems looking to be partially or fully energy-independent. These systems power homes through energy outages and low-generation days in off-grid homes, maximize self-consumption, and more.

In this article, you will learn the basics of battery storage systems, how they work at home, their benefits, and even the best solar battery home storage systems available. 

What Are Home Batteries and Are They Worth It?

A home power battery bank is an electrical device that stores DC energy and delivers it at the right AC voltage, powering all types of appliances and electronics. A home electric storage battery can be powered with clean energy and/or grid-supplied electricity.

The home storage battery system can store energy for use later, making them entirely worth it. This section analyzes some of the significant aspects that make home batteries versatile and beneficial for every type of home.

Solar and Wind Energy Can Be Stored for Later Usage

Generating excess solar power is ideal for net metering to reduce the cost of electricity bills for grid-tied homes. Instead of sending that extra energy to the grid, you can store it for later use.

A solar panel battery storage system stores enough energy to power a home for several hours and even more than a day, depending on the battery capacity and house consumption. A solar battery backup system will also increase your solar energy self-consumption.

Off-grid homes with solar panels installed need a solar panel battery bank. Solar panels charge the solar battery backup system, allowing this stored energy to be used later when the panels are not generating. Aside from providing a backup energy storage system, home batteries offer the correct DC voltage required for the inverter. This ensures a stable AC voltage to power all devices at home.

Power Outages Will Not Be an Inconvenient Anymore

Power outages can happen at any time because of technical failures in the grid or more regularly due to weather-related disasters. Having a backup energy storage system will ensure uninterrupted power, which will give you the energy independence you deserve, powering your home through any crisis.

Grid-tied homes mainly use solar battery banks as a backup energy storage system, storing the generated energy for later use. During any power failure, the home battery activates and delivers power to every outlet at home, ensuring electricity for all appliances.

Using a battery bank for a home will ensure you can power the most crucial loads in times of need. This means you can keep your lights on, maintain the refrigerator/freezer running, power electronics, keep the Internet on, and power regular appliances.

You Can Save Money When Time-of-Use (TOU) Tariffs Are Fully Applied in All States

Applying time-of-use (TOU) tariffs is a worldwide scheme that reduces power consumption in peak hours, avoiding grid overload by reducing unnecessary loads. This action allows utilities to apply high-cost tariffs at peak hours and low-cost tariffs with more electrical clearance.

While TOU tariffs are still not widely used throughout the United States, it has already been tested in several states with promising results. A home electric storage battery allows you to use stored energy at high TOU tariff times and charge the home storage battery at hours with low-rate tariffs to save some money.

How Do Home Batteries Work?

From a practical point of view, a home solar battery storage does the same function as a fuel power generator would but with zero contamination and almost no noise. A home battery bank can store high amounts of energy to be delivered on-demand, powering homes for several hours.

To better understand how a home backup battery bank works, we will explain the inner function of home batteries and their major components.

Lithium Batteries Are the Core of Home Batteries

Home batteries can store high energy capacities because they use a large bank of lithium stationary energy storage batteries. These batteries work similarly to other lithium options on the market but with larger capacities ranging from 5 kWh to 20 kWh.

Home battery storage systems tend to use Lithium-Ion, Lithium-Iron, or LiFePO4 (LFP) energy storage technology. Both technologies use an electrolyte made out of lithium salts and an anode out of high-quality graphite, but the cathode is where the main difference lies. Li-Ion batteries use a Lithium-Cobalt-Oxide (LiCoO2) or Lithium-Manganese-Oxide (LiMn2O4) cathode, while LFP batteries use Lithium-Iron-Phosphate (LiFePO4).

To deliver electric power, both batteries go through an electrochemical process between the plates and the electrolyte. When batteries are discharged, the anode goes through an oxidation process that produces electrons flowing to the load, powering it. At the same time, positive ions flow through the electrolyte to balance the process. The opposite occurs when batteries are being charged back up again.

Built-in Inverter

Most home batteries include a built-in inverter transforming DC stored energy into a 120/240 VAC pure sine wave output that goes directly to the home to deliver AC energy. The output power comes from battery-powered appliances like grid electricity with a high power rate for most built-in inverters.

Charge Controller Replacement

Home battery systems include one or, in most cases, several MPPT charge controllers which optimize the matching power transferred from PV modules to the batteries. This system also diverts power from the panels to the home, delivering as much energy as demanded, ensuring uninterrupted power while the batteries are being charged.

BMS Systems

To ensure optimal safety for homes, battery banks include building management systems (BMS), which supervise and control every aspect of the battery and energy usage. The BMS system allows for cut-off charging at the right temperature to ensure safety, charges the batteries at the proper parameters, notifies homeowners of situations related to the batteries, and much more.

Additional Features

As you have seen up to this point, home battery storage systems can replace charge controllers, inverters, and batteries in PV systems, but they also have several new features included.

Home battery banks can have TOU tariff optimization, which will save money by allowing you to consume energy at low costs and provide backup power at hours with high tariffs. These batteries can also be fully monitored and configured using mobile apps, providing you the energy independence and control that you need at the palm of your hand.

Limits to Whole-Home Battery Backup

Home energy backup storage systems are practical, functional, versatile, and can ensure uninterrupted power even when most houses in the city are without electricity due to outages. Even while this technology is quite remarkable, like any other, it has its limitations. This includes considering household consumptions, power limitations of some components, system sizing, and lifetime.

Energy Capacity Limits

A home battery bank design should be matched to the consumption requirements of the user. However, there can be limitations on the number of units that can be coupled to the system.

Average homes looking to get the best performance out of a home battery system should ration the battery. They should only power critical loads alongside minor ones. This means powering the necessary bulbs or using solar lights and a few electronics such as small solar power banks and running the freezer/refrigerator to keep food in good shape. Large loads like A/C systems, home heaters, or water heaters should be avoided since these will rapidly drain the battery.

US citizens have a monthly average consumption of 877kWh or under 30kWh daily consumption. They tend to power high-consumption loads like A/C systems, water heating, and similar ones. A high-capacity home storage battery, with capacities of 15–20 kWh, can power the average home for more than a day (assuming around 13.5kWh daily consumption) if high-demand loads are excluded. Likewise, it can be between 50% and 66% if high loads are included in the consumption because they account for up to 55% of the consumed energy.

Inverter Peak Power Limits

The inverter of the battery is another one of the significant components limiting the usage of home battery banks. The power delivery capacity of the inverter means how much simultaneous power you can use at your home by the hour. Some batteries in the list only have 3 kW inverters, some 5 kW inverters, and only a few have inverters delivering up to 9 kW.

While this is a limitation, most inverters have a designed surge power capacity much higher than the standard power usage. This is required to start AC/DC motors included in refrigerators, water pumps, and other high-consumption electro domestics.

PV and Battery Sizing

Just like there are autonomy limits concerning battery capacity and house energy demands, the same happens for PV systems. While a battery can only power a home for a day and a half for an energy-efficient home, most PV systems are not large enough to power both the home and charge the total capacity of the batteries, which is especially important when living with off-grid power.

15kWh batteries can give one day and a few hours of autonomy, while 20kWh high-capacity batteries can power the home for one day and around 12 hours. However, most PV systems cannot charge the whole battery back up again and power the entire house. The average 5kW DC PV array could deliver up to around 20kWh daily in a California household, but this does not include home powering.

To ensure uninterrupted energy for the home, you should consider a PV system that works as a complete solar battery charger and powers the house simultaneously. This means a system that delivers approximately 20kWh for the battery + 13.5 kWh for the home = 33.5kWh in a whole day would require around an 8.5kW PV system, a more extensive system.

Lifetime Periods

The lifetime of a home battery bank should also be considered in the limitations. Depending on the usage, most batteries can last for up to 12–15 years. This means you should consider replacing the batteries in the home battery bank over time.

Some batteries in the review section are expandable, and in some cases, they can even allow you to replace the internal lithium battery. This will be relatively cheaper than replacing the whole unit and much more convenient for your budget.

Review Section

If you want to know the best solar battery home storage systems, this section is for you. Here, we review some of the most outstanding and reliable home energy storage systems designed by quality brands like Tesla, LG, Enphase, Panasonic, Nissan, and many others. 

1. Tesla Powerwall 2

Tesla Powerwall 2 – Tesla

The Tesla Powerwall 2 is a high-end home battery with superior technology and aesthetics, coupled with solar panels to be used as a Tesla solar wall. The Tesla app allows you to receive alerts, monitor the system, and configure energy usage for Tesla Powerwall 2.

With a designed capacity of 14 kWh and a 96% DOD, you can fully use 13.5 kWh of this battery. The Tesla home battery can be operated at extreme temperatures of -4º to 122º F, but it is recommended to be used from 32º to 86º F.

This home battery includes a built-in 5 kWh pure sine wave inverter with 4 MPPT trackers. The inverter operates at a continuous power output/input of 5 kW, and it can deliver a peak power output of 7 kW for 10 seconds.

2. LG CHEM RESU10H

LG CHEM RESU10H – LG CHEM Catalog

The LG CHEM RESU10H is one of the most unique home battery storage systems. This battery comes in two models, the Type-C and the Type-R, with varying compatible inverters depending on the model. The Type-C battery is compatible with SMA Sunny Boy inverters, while the Type-R is compatible with Huawei, Solis, and SolarEdge inverters.

Both batteries have a designed capacity of 9.8 kWh with a 95% DOD, delivering a usable capacity of 9.3 kWh at a max. It also has a continuous current of 63A. The Type-R battery can operate at a 350–450 V voltage range and the Type-C at 430 – 550 V.

To expand the capacity of the LG CHEM RESU10H home battery, we recommend the Type-R option. This model can be coupled with the RESU10H Type-R Secondary pack, increasing the ability to 18.6 kWh.

3. Nissan xStorage

Nissan xStorage – Eaton: Powering Business Worldwide

Nissan and Eaton united to create the Nissan xStorage home battery. This battery gives Nissan EVs a second life for a fully integrated backup energy storage system, including low, medium, and high capacities with built-in inverters.

The Nissan xStorage comes in capacities of 4.2kWh, 6kWh, or 10.08kWh. These batteries operate at 90V and can be charged/discharged with DC currents of 70A, 70A, and 75A, respectively, or power input/outputs of 3.83kW, 4.89kW, and 6.38kW. This battery can be operated at a temperature range of 32ºF to 86ºF, and it can be stored at 14º–104ºF.

The Nissan xStorage built-in hybrid inverter ranges in capacities, delivering 3.6kW, 4.6kW, and 6.0kW, respectively, for each battery. This inverter operates with a DC power input of 100V–500V and an input current of  20A per MPPT, including two MPPT trackers for max.

4. MeritSun 10KWh power wall

Meritsun 10kWh Powerwall – MeritSun

The MeritSun 10kWh Powerwall is a home battery with a medium to high capacity of 10kWh with an 80% DOD, delivering a usable power of 8kWh. The internal battery handles standard currents of 50A for charging/discharging, maximum discharging currents of 120A, and a peak current of 300A for 1 second.

The 5kW built-in hybrid power inverter allows for a maximum PV power input of 8kW. This inverter can deliver 5 kVA, including a 5 kW output for the panels and 3.6 kW for the battery. The hybrid inverter provides max continuous currents of 66A or a peak power output of 4.5 kW for 30 seconds.

5. Enphase Encharge 10

Enphase Encharge 10 – Enphase Encharge 10 Data Sheet

The Enphase Encharge 10 is a high-quality home battery designed with state-of-the-art technology optimized for TOU tariff usage. It delivers a grid-forming capability for backup home energy applications. The battery is compatible with grid-tied PV systems, Enphase microinverters, and the Enphase IQ Envoy.

This energy storage system has a designed capacity of 10.5 kWh composed of three 3.36 kWh batteries with a 96% DOD, delivering a usable capacity of 10.08 kWh. The internal batteries operate at a temperature range of 5º–131º F. However, the recommended operating temperature goes from 32º to 86º F.

Instead of a large inverter, this battery includes 12 embedded IQ 8X-BAT microinverters operating at 240VAC to deliver a continuous power output of 3.84 kVA or peak power of 5.7 kVA for 10 seconds. The inverter array can provide a 16A constant current or a peak current of 24.6A for 10 seconds.

6. Panasonic 11.4 kWh EverVolt

Panasonic 11.4kWh EverVolt – Panasonic EVAC-105 / EVDC-105 Energy Storage datasheet

One of the most innovative and outstanding performing home batteries is the Panasonic 11.4 kWh EverVolt, coming in DC- and AC-coupled versions. This battery can be optimized for off-grid systems or as a backup energy system for traditional grid-tied homes.

The AC-coupled EverVolt can work with pre-existing PV systems with an installed inverter. The DC-coupled version replaces the inverter coupled with a 6.5 kW maximum PV array operating at 120–500 VDC, with an MPPT working from 250 to 430 VDC.

The EverVolt has an 11.4kWh usable battery capacity for a constant power output of 4.6kW (23A at 120 VAC). Better yet, this battery can deliver a high-power output of 6.5kW for 5 seconds or 7.5 kW for 1 second. The EverVolt batteries can be charged from 41ºF to 131ºF and discharged from 32ºF to 122ºF. When storing the EverVolt battery, Panasonic recommends doing so in a temperature range of -13º–158ºF.

7. Greensun 10KWh Power Wall

Greensun Solar 10kWh Power wall – Greensun Solar

The 10kWh Greensun Powerwall is a wall-mounted home solar battery bank with a LiFePO4 high capacity. This battery features a quality BMS protection against overcurrent, overvoltage, short circuit, and overtemperature.

The inner solar battery storage can be discharged to 100% DOD, allowing homeowners to use the 10.24 kWh capacity fully. This battery can be released at -4º–140º F and charged at 32º–140ºF. If you are storing this battery, Greensun Solar recommends doing so at -4º–113ºF.

8. Sonnen Eco

Sonnen Gen 3 – Sonnen

The Sonnen Eco Gen 3 is the new generation of battery systems for off-grid and grid-tied homes. This model comes in a wide range of options going from the Eco 5 to the Eco 20 (increasing in 2.5 steps). The number of the model defines the capacity of the battery and other specifications.

The capacity for the Eco 5 to the Eco 20 goes from 5kWh to 20kWh in 2.5kWh steps. However, with a 90% DOD, this capacity goes from 4.5kWh to 18kWh in 2.25kWh steps. All Sonnen Eco batteries can operate in a temperature range of 41º–113ºF.

There are three types of built-in inverters in the Sonnen Eco series. The Eco 5 includes a 3kW inverter delivering 12.5A currents, the Eco 7.5 a 4kW inverter providing 16.67A currents, and the Eco 10+ (10 and beyond) an 8kW inverter having 33.3A currents.

9. Pika Energy Harbor

Harbort Smart Battery (PWRcell) and Pika Islanding Inverter (PWRcell inverter) – Pika Energy (Generac)

The Pika Harbor Smart Battery is a high-end model compatible with PV systems, optimized for TOU tariffs, including a zero-export system. After Pika Energy rebranded as Generac, the Harbor series was renamed to PWRcell. This battery is recommended to be coupled with the Pika Islanding Inverter (PWRcell inverter).

The Pika Energy Harbor battery comes in four options: Harbor 3, 4, 5, and 6. The Harbor 3 includes three battery modules for a designed capacity of 10.1kWh. Likewise, each module has one additional battery increasing the capacity to 13.5kWh, 16.9kWh, and 20.3kWh, respectively.

With an 84–85% DOD, these batteries have a usable capacity of 8.6kWh, 11.4kWh, 14.3kWh, and 17.1kWh. The Harbor 3 can deliver a continuous power output of 3.4kW, increasing by 1.1kW with each additional module. These batteries are recommended to be used at 41º–113ºF, but they can be operated from 55º to 86ºF.

10. SimpliPhi’s

SimpliPhi’’s home battery – SimpliPHI

The SimpliPhi Power AccESS home battery system is a fully integrated and automated home storage system using a Sol-Ark inverter and AmpliPHI batteries. There are two available models, each varying in capacity.

After considering the 80%, this system has a usable capacity of 12.38–15.48 kWh. The four-battery model has 15.48 kWh, while the five-battery one goes up to 19.35 kWh. These batteries can be charged at a temperature of 32º–120ºF, but they can be operated at -4º–122ºF.

Both batteries include a Sol-Ark 12K inverter which can receive a solar PV power of 12kW with an MPPT voltage range of 150–425 VDC, delivering a power output of 9kW. This inverter can be used for a 120V L-N or a 240V L-L configuration. However, you can parallel stack it to get up to a three-phase design.

Home Battery Storage – FAQs

To help you answer any doubts, we looked to answer the most frequently asked questions about home battery banks. Here, you will learn many interesting facts about home battery storage systems.

How Big of a Battery System Do I Need to Run My Entire Home?

To run an entire home, you need to compare the power output of the inverter and batteries against the household power demand. Peak power consumption can be seen on your utility bill and can give you a reference of how much power you would need in the worst-case scenario. All inverters in the list can deliver at least 3kW, and some go as high as 9kW for instantaneous demand. This is why all listed home battery systems can efficiently run the average home.

As for energy demands, you would need to match your annual energy demand that can be found from your utility to the capacity of the home storage devices. Some of them will be able to cover all your needs, while some may fall short. For instance, two Tesla Powerwall 2s should cover all or almost all the demand in most cases.

How Long Can a House Run on a Battery Bank?

To calculate the running time for a home powered by a battery bank, you should consider the daily power consumption against the battery’s capacity. US homes consume on average 30 kWh. A home with that consumption can run for around 16 hours with a 20kWh battery.

Energy-efficient homes can reduce that consumption by 55%, requiring a daily power supply of 13.5 kWh. With this demand, you can run the house for +24 hours with a 15kWh battery and almost 36 hours with a 20kWh home battery.

Battery Bank vs. a Generator: Which One Is Better?

Fuel generators are noisy and contaminant generators that can be very impractical for off-grid homes. These generators burn fossil fuels which are bad for the environment, might require storing gasoline that is a fire hazard and has to be acquired at gas stations and produce loud noises of 100 dB. These noises can be heard up to 23 feet away and be quite annoying, even for your neighbors.

On the other hand, battery banks are eco-friendly and reasonably practical, making them much better options. These systems do not produce contamination since they can be charged with residential solar-wind, produce barely audible noises, and will allow you to achieve much higher solar self-consumption or even living off-grid.

Are Lithium Batteries Better Than Lead-Acid?

Lead-acid batteries are bulkier, heavier, handle lower currents, and have a lower energy density when compared to lithium ones. Almost every aspect of lithium batteries is superior to lead-acid ones.

Lead-acid batteries have a maximum of 80% DOD, while lithium ones go as high as 95–100% DOD. The life span for both technologies also differs. Gel batteries are the more long-lasting options from lead-acid technology, and they only deliver 500–1500 cycles. On the other hand, some lithium batteries used for home energy storage systems in the list can provide 10,000 cycles backed by a warranty.

How Do I Calculate How Much Battery Storage My Home Needs?

To calculate the battery capacity for your home, you should consider how many hours of backup energy you need compared to the home power consumption.

Take a look at your energy bill, and find out what would be your daily average energy consumption across the year. Then, balance your daily consumption with the battery storage capacity to determine how many battery units you would need to cover your entire demand.

Otherwise, if you wish to select only critical loads, you need to estimate the number of hours you use for each essential device and multiply it by the power rating in watts. After which, compare this total value with the battery storage capacity to know how many units you would need.

Will a Home Battery System Save Me Money?

Home battery systems can save you money and ensure power stability through any outage. These batteries allow you to live off-grid with solar panels or achieve solar self-consumption to reduce your electricity bill considerably. These batteries are also optimized for TOU tariffs, enabling you to charge them at low-cost energy and sell them back to the grid at high prices. Learning where to buy home batteries is also important to save money and get the best deals.

Should I Build a Home Battery Bank by Myself?

Learning how to build a battery bank for a home or DIY-ing it is no easy task. You will require technical skills to install large-capacity batteries in parallel/series, a home inverter, and other significant security and electric control components.

The cost for a DIY home battery bank can end up being similar to some quality batteries on the list. However, it is unlikely that it will achieve the same features. A DIY home battery does not have monitoring apps, TOU tariff optimization, nor many features included in high-end home battery systems. Thus, we recommend being on the safe side and going with a quality brand solar home battery storage system.

What to Look for in a Home Battery Storage – Buyer’s Guide

When buying a home battery storage system, it is important to acquire the best fit for your home, ensuring many features and benefits. In this section, we go over some important aspects to consider when picking a home energy storage system.

Stackability

Some homes require more energy than others or want a higher capacity to ensure power for more hours. This is where stackability comes into place.

Stackability is the possibility to install many units together, increasing the overall capacity. For instance, the Tesla Powerwall 2 allows for the installation of 10 units for a total capacity of 135.00 kWh. Likewise, a PWR cell can be installed alongside another unit to achieve 34.2kWh.

Power Capability

The power capability of home energy systems means the simultaneous power this unit can handle. For this, you should consider the battery discharge limitations and the inverter power output. For instance, all batteries on the list deliver power outputs equal to or superior to 3kW. Some go as high as 5kW, and even a few can provide 8–9kW.

Budget

The budget is always essential, so you should consider the price for the battery regarding how much time you can run your home, the expandability of the battery, and other beneficial features. You can also factor in return on investment, considering how much money it will save you for TOU tariffs, solar self-consumption, and others.

Outdoor/Indoor

Some home battery storage systems can be installed outdoors, while others have to be installed indoors with certain protections. This is especially important for places with extreme weather affecting the performance of the battery. You can consider the IP rating for the batteries to know how they will perform outdoors/indoors.  

Smart Energy Management

Home energy storage systems are not just batteries stacked with inverters. They also have many features and benefits for your home, and some even include Smart Energy Management (SEM).

SEM is a feature ensuring your home battery will reduce coincident high loads, so you never drain your battery too fast or demand too much power from the battery/inverter. For instance, the SEM can limit the usage of water heaters when A/C units are working, limiting the simultaneous power demand.

AC vs. DC-Coupled Batteries

Some brands design AC-coupled batteries, others DC-coupled, and some design both, but what does this mean for you?

DC-coupled can manage DC loads and PV systems with one fully integrated system, replacing the battery bank and the inverter for the PV system. AC-coupled batteries are slightly less efficient, but they are ideal for homes with pre-existing PV systems since they can coexist with panels, old batteries, and another inverter without presenting an inconvenience for the power operability of the house.

Conclusion

Home energy battery systems are the best option to ensure power continuity in weather-related power outages or any other electrical crisis. These energy backup systems give your home the ability to be powered 24/7 when living off-grid or upgrading to a net-zero home with solar panels by achieving solar self-consumption.

Solar home battery storage systems can ensure you reduce costs in electricity bills by using clean and cheap energy. Aside from being highly convenient in case of electrical emergencies and even upgrading your home to net-zero, they can save you money. They can also optimize energy usage for TOU tariffs, allowing you to store energy at low prices and sell it again at high prices.

The benefits of home solar battery storage systems are exceptional and quite advantageous. In the Review section, you will find some of the best residential energy storage systems with a wide variety of specifications that adapt to the needs of many homes. Using the buying guide, you can pick the best battery for your home, ensuring power stability and saving money.