If you have a power outage and it looks like it will be out for an extended period of time, you need backup power from a battery backup system or battery pack.
You can maintain power for several hours with a Air-cooled home generator run on gasoline or propane, or you can buy a much more expensive liquid-cooled generator to keep your lights on longer.
But if power outages happen frequently where you live, you might consider installing a backup battery pack to power you when you’re off the grid.
These battery storage systems can include dry or wet batteries. Typical dry batteries are lithium-ion batteries used in mobile devices or lithium ferro phosphate batteries commonly used in solar backup battery systems. They don’t tend to work well in very hot or cold environments, and some won’t work if the temperature is below freezing.
Wet batteries use a liquid electrolyte to generate electricity. Lead-acid batteries use lead plates embedded in the sulfuric acid electrolyte –or acid batteries. Batteries may also contain gel. A gel battery is a form of lead-acid battery of the VRLA (value adjusted lead acid) type. The acid electrolyte is mixed with a silica to create a gel that won’t leak if the battery is spilled.
Other batteries have an absorbent glass mat (AGM) in place to keep the electrolyte in contact with the battery’s plates. However, AGM batteries can lose power in very cold conditions.
For a seemingly endless supply of energy, consider a solar panel system to connect to your energy storage system. Your backup battery system will be charged by solar energy so you have a regular supply of solar power from your solar cells.
Solar batteries, also known as PV (photovoltaic) solar cell systems, will charge your home battery system with renewable energy. If you can’t afford to buy a full set of solar panels, a 13.4 kWh (kilowatt hour) Tesla Power wall and an uninterruptible power supply (UPS) which is also a surge protector and turns on itself. When the power is out, how can you run important items if the power is out?
If you just want to run a few low-power devices, charge your mobile device, or plug in a light, then a portable battery with a solar charger may be more suitable for your budget. I’ve included some lower-cost items at the bottom of this list.
There are some important considerations and calculations you need to make before deciding how large your backup system needs to be. You want your home battery storage system to be enough for your needs. There’s more on that at the bottom of this guide.
Also: Backup battery vs backup generator
- 10 years warranty
- Stacking up to 10
- Dedicated application for energy management
- Large power distribution
- Very expensive
- Only compatible with Tesla branded solar panels
Capacity: 13.5kWh (kilowatt-hour) | Energy sources: Solar panels | Control: Dedicated Application | Multi-unit configuration: Correct
The market leader in battery backup systems, Tesla Powerwall, is equipped with all the bells and whistles to make converting your power to battery backup as simple as possible. Recharge with solar panels and enjoy stored solar energy for those times when you’re off-grid.
The Tesla Powerwall+ will give you an energy capacity of 13.5kWh and has a power rating of 7.6kW (kilowatt) providing 5.8kW of continuous power in the absence of sun. Powerwall+ has a ten-year warranty and can be monitored and managed using its app. You can only buy the Powerwall if you also buy Tesla solar panels.
You can connect up to 10 Powerwalls to ensure you have the right sized backup battery for your home. It is recommended to use Tesla Powerwall with solar panel system. Some states like WA (22%) offer a Federal Solar Investment Tax Credit to help with costs.
- modular design
- Control unit and intuitive application
- 10 years warranty
- Works with most solar panels
- Very, very expensive
- Price does not include solar panels or installation
Capacity: Up to 36kWh | Energy sources: Solar panels | Control: Dedicated applications and control devices | Multi-unit configuration: Correct
The standard Generac PWRcell system delivers 9kWh of storage from three Lithium Ion battery modules rated at 3.0kWh. The system includes an inverter and battery storage cabinet.
The good thing is that PWRcell will work with solar panels from most manufacturers so there is no vendor tie-in. Its modular design means you can expand your storage capacity in increments from 3kWh up to 36kWh. It has a ten-year limited warranty and can be managed and monitored with an app.
- 10 years warranty
- modular design
- Stack up to 3 units
- Not as flexible as other systems
Capacity: Up to 102kWh | Energy sources: Solar panels | Control: Dedicated Application | Multi-unit configuration: Correct
The Panasonic EverVolt Standard Model EVDC-105-4 is a DC coupled 11.4 kWh battery storage system. It features a modular design with an integrated 5.5kW DC 120/240Vac inverter and a PowerHub programmable controller. It will provide 4.8kW of battery output power continuously at 25A and has an average backup of 6 hours. It has an app to monitor and control it, and is backed by a ten-year warranty.
- Perfect for most homes
- Automatic remote update
- great warranty
- Extended warranty costs
Capacity: 10.08kWh | Energy sources: Solar panels | Control: Dedicated Application | Multi-unit configuration: Correct
The Enphase IQ Battery 10T will give you 10.5kWh of energy capacity and deliver 5.76kVA (kilo-volt-ampere) at peak power. It includes three base Encharge 3T storage units. The battery is made of Lithium Ferrous Phosphate (LFP) and the unit has a rated power of 3.84KW.
It cools passively so there are no moving parts or fans. It has a ten-year limited warranty and a mobile app to monitor and control the system. Professional installation is a must for this battery storage system.
In our opinion, Tesla Powerwall+ is the first choice for a backup battery system for the whole family. It has a capacity of 13.5 kWh, a 10-year warranty, and an intuitive companion app to monitor energy distribution and usage. You can even create a network of up to 10 Powerwall+ units to adapt to your changing energy needs.
|
Backup battery at home |
Price |
module |
Capacity |
|
Tesla electric wall+ |
$12,000 |
Correct |
13.5kWh |
|
Generac PWRcell |
20,000 USD |
Correct |
36kWh |
|
Panasonic EverVolt |
$15,880 |
Correct |
102kWh |
|
raise IQ |
10,000 USD |
Correct |
10.08kWh |
You will need to determine the power consumption and voltage of the entire household. Thankfully, Lowe’s has a handy spreadsheet to help you figure out your energy needs. Once you know how many watts and volts your appliances use, you’ll want to add at least 20% to the total; that way, if you add electronics or home appliances or something that starts consuming more power than usual, your system will be able to keep up.
And if retail and installation prices seem a bit high, many places offer some sort of payment plan so you can split the final cost into more affordable monthly payments.
|
Buy this home backup battery… |
If you need… |
|
Tesla electric wall+ |
Comprehensive and scalable home backup battery |
|
Generac PWRcell |
Home battery backup system compatible with third-party solar panels |
|
Panasonic EverVolt |
A modular battery backup system for changing energy needs |
|
raise IQ |
A compact battery backup system for smaller homes |
In addition to retail price and installation costs, we carefully considered peak voltage and amperage, starting and running. Since these are permanent installations, you need to ensure that the system is capable of handling the electrical load of all your appliances on a daily basis. If you choose a system with less power than necessary, you risk damaging the wiring throughout your entire house; but if you choose something with more capacity, not only will everything run smoothly, but you’ll also have room to expand as your power needs change.
Backup battery systems are usually charged by utility grid electricity or solar energy. If you live in a sunny area, consider using solar power to charge your battery during the day. Also, if your power outages don’t happen often, consider getting extra batteries when the cost is low.
You need to check the capacity of the battery. This is usually measured in kilowatt-hours (KWh). Any output, such as an inverter, will be measured in watts or kilowatts. Typically, the battery capacity should be greater than the energy generated by your system, and ideally should store enough energy to cope with a 24-hour power supply.
You also need to measure the surge current requirements of the devices you need to power — especially if you need to start something like a sump pump motor. Don’t expect to be able to power things like pool filters or air conditioners for days on end.
Cost is also a big issue — especially if your requirements total over 15KWh of inverter capacity or more than 30KWh per day for your battery. You’ll also need to account for inefficiencies, voltage drops, and other losses, and plan to respond to any eventuality.
You will need to carefully consider the maximum load in KWh per day when calculating how much battery you need. If your power requirements are low — such as lighting — most backup systems should be able to accommodate this. However, if you need to run items such as sump pumps, air conditioners, or items with heavy starting loads, then you also need to consider peak loads.
Sometimes, you don’t need uninterruptible backup power. That’s where smaller, more emergency devices come in to provide backup power only when you need it. Here’s a short list of emergency power stations that I think are great options:
