Home backup power system (ETHOS battery and LUXPower inverter)

When looking for a home backup power system, consider your specific power needs, the ability to use solar panels (or a gas powered generator), and grid charging options. In this post I'll outline why I chose a particular system, how it works, and what it powers (and why).

Sufficient Battery Storage and Inverter Capacity: Enough storage and a powerful inverter to handle multiple appliance power needs.

The inverter converts DC (from the batteries) to AC and a Manual Transfer Switch is used to connect to specific breakers in my home. More details on how the system works and how to set it up are below.

Check out Solar Power Basics

Use this: Watt Power Meter to measure specific appliance and how much power they use. Details on this setup and what it powers are found below.

Check out Solar Power: Understanding Watts, Amps, and Volts

Take me to: Examples of Daily Power Usage

Tying into the Main Breaker: How will the system tie into my main breaker, and how will I manage which breakers are tied to the batteries?

The inverter sends AC power through a Manual Transfer Switch and each breaker in the manual transfer switch is wired direct to the breaker in your home's main panel.

Essential Appliances to Power (what I've chosen):

• Well Pump
• Commercial Freezer
• Miscellaneous Outlets and Lighting
• Electrical System for Propane Furnace, Range, & Water Heater
• Take me to: Examples of Daily Power Usage

Take me to: How this Battery System Works

Use this guide to make an informed decision and ensure your home is prepared for any power disruptions.

Battery ((3) 48V ETHOS 5.12kWh Stackable Battery Modules)

The 15.3kWh capacity of the Ethos battery (what my system is, 3 stackable battery modules) ensures that essential appliances (that I picked), such as my large freezer, water pump, and electronics for the propane water heater and furnace, will stay powered during outages. With built-in fire suppression and a robust Battery Management System, it's a safe and reliable choice. The modular design allows for future expansion, and the efficient Lithium Iron Phosphate technology offers long-lasting energy storage. This setup provides a dependable solution for keeping critical appliances running smoothly in emergencies.

Inverter (LUXPower 12kW Hybrid Inverter)

The 12kW LUXPower inverter is perfect for ensuring that essential appliances stay powered. It can handle high power demands, making it suitable for what I'm powering via battery. With features like smart load management and seamless switching between grid and battery power, it ensures consistent operation during outages. Additionally, its versatility allows it to work both with and without the grid, providing flexibility and reliability in emergencies.

Overall Benefits

With the 15.3kWh battery capacity and 12kW inverter, you can power essential appliances for extended periods during an outage. The high capacity and efficiency mean you can maintain critical functions in your home, ensuring preparedness and peace of mind during emergencies.

Taking a look at the current cost with coupon code BUCKHORN10 (which gets you 10% OFF).

Comparison: BigBattery 12kW 15.3kWh Ethos vs. Tesla Powerwall 3

The BigBattery Ethos 12kW 15.3kWh system offers superior capacity, affordability, installation flexibility, and robust safety features compared to the Tesla Powerwall 3. Its higher power output and compatibility with both solar and wind power systems make it an excellent choice for those seeking a versatile and powerful energy storage solution. Both include a 10 year warranty.

Battery Capacity:

Price:

• Ethos: $9,621 (with coupon code BUCKHORN10) You can DIY this.
• Tesla: $9,923 when I priced it in July 2024 (excluding installation). Tesla sells it through certified installers only, so no DIY.
• Advantage: Ethos is more affordable with the coupon code.

Installation:

Safety and Robustness:

Scalability:

Monitoring:

3 × 48V ETHOS 5.12kWh Stackable Battery Modules

• Purpose: Store energy for use during power outages or for off-grid applications.

ETHOS Control Box

• Purpose: Manage and control the operation of the battery modules and system performance.

LUXPower 12kW (18kPV) *Hybrid Inverter

• Purpose: Convert stored DC power from the batteries to AC power for home use and manage grid-tied and off-grid functionality.
• *A hybrid inverter is a type of inverter that can manage power from multiple sources, such as solar panels, batteries, and the electrical grid. It seamlessly switches between these sources to provide a continuous power supply. In the context of the Ethos Energy Storage System, the LUXPower 12kW Hybrid Inverter allows for both grid-tied and off-grid functionality, converting DC power stored in the batteries to AC power for home use while also handling solar input and grid power.

15kWh Ethos Controller to Battery Power Cable 4ft (1220mm) (CBL091)

• Purpose: Connect the control box to the battery modules for power transmission and communication.

Manual Transfer Switch

• Purpose: Connects Ethos Battery and LUX Inverter to the main panel, allowing control over which breakers are backed up.

DC Quick Disconnect Switch

• Solar Panels
• Solar Panel Wire
• Solar Panel Wire Conduit
• Conduit for Inverter/Battery/Switch/Panel Setup
• Wire (as applicable)

The Ethos Battery is where you store energy. The battery can receive power from:

The reason the battery can store power from these sources is the Hybrid Inverter. The LUXPower 12kW Hybrid Inverter is capable of:

The Ethos Battery & the LUXPower Hybrid Inverter (together) offer:

1. Well Pump:
   • Average wattage: 1,500 watts
   • Usage time: Assume it runs for 1 hour per day.
   • Energy consumption: 1,500 watts * 1 hour = 1,500 watt-hours (1.5 kWh) per day.
2. Commercial Freezer:
   • Average wattage: 1,250 watts
   • Usage time: Typically runs continuously, but the compressor cycles on and off. Assume it runs for 12 hours a day.
   • Energy consumption: 1,250 watts * 12 hours = 15,000 watt-hours (15 kWh) per day.
3. Miscellaneous Outlets and Lighting:
   • Average wattage: Assume 200 watts for outlets and 300 watts for lighting.
   • Usage time: Outlets run for 4 hours and lighting for 6 hours a day.
   • Energy consumption: (200 watts * 4 hours) + (300 watts * 6 hours) = 800 + 1,800 = 2,600 watt-hours (2.6 kWh) per day.
4. Electrical System for Propane Furnace, Range, & Water Heater:
   • Propane Furnace: 1,000 watts, running for 4 hours a day during cold weather.
   • Propane Range: 600 watts, running for 1 hour a day.
   • Propane Water Heater: 1,000 watts, running for 2 hours a day.
   • Energy consumption: (1,000 watts * 4 hours) + (600 watts * 1 hour) + (1,000 watts * 2 hours) = 4,000 + 600 + 2,000 = 6,600 watt-hours (6.6 kWh) per day.

Total Energy Consumption

Adding up the daily energy consumption for all these appliances gives you an overall picture:

• Well Pump: 1.5 kWh
• Commercial Freezer: 15 kWh
• Miscellaneous Outlets and Lighting: 2.6 kWh
• Electrical System for Propane Furnace, Range, & Water Heater: 6.6 kWh

The 12K LUXPower Inverter is designed with several features to help prolong the life of your batteries. Here are the detailed ways in which it achieves this:

1. Battery Management System (BMS) Integration:
   • The inverter integrates with the Battery Management System (BMS) to monitor and manage the battery's health. The BMS helps to balance the charge across individual cells, preventing overcharging and deep discharging, which are detrimental to battery life.
2. State of Charge (SOC) Management:
   • The inverter continuously monitors the state of charge (SOC) of the batteries. It ensures that the batteries operate within the optimal charge range (20% to 80%). The inverter can be programmed to start charging the batteries when they drop to a certain level and stop charging when they reach the upper limit, thus avoiding deep discharges and overcharges.
3. Charge and Discharge Control:
   • The inverter controls the rate of charge and discharge to ensure that the batteries are charged and discharged at appropriate rates. Fast charging can generate heat and stress the battery cells, while controlled charging extends battery life. Similarly, the inverter limits the discharge rate to prevent rapid depletion of the battery.
4. Temperature Monitoring and Control:
   • The inverter is equipped with temperature sensors that monitor the battery temperature. Extreme temperatures can significantly affect battery health. The system can adjust the charging and discharging parameters based on the temperature to ensure optimal operation and longevity of the batteries.
5. Scheduled Charging:
   • The inverter allows users to set up scheduled charging times. By scheduling the charging during off-peak hours or when solar energy is abundant, the batteries can be charged more efficiently and without stressing the power grid or the batteries themselves.
6. Smart Load Management:
   • The inverter can manage connected loads intelligently. By prioritizing essential loads and shedding non-essential ones during low battery conditions, it ensures that the batteries are not excessively drained. This helps in maintaining a healthy SOC and extends battery life.
7. Firmware Updates:
   • Regular firmware updates from LUXPower can enhance the battery management algorithms, improving the efficiency and lifespan of the batteries. Users can easily update the firmware via the inverter’s interface or connected devices.
8. User Alerts and Notifications:
   • The inverter provides alerts and notifications for maintenance and operational status. Users are notified when the batteries need attention, such as a communication fault or a loose connection. LiFePO4 batteries never get an equalization charge. That is a lead-acid practice. Timely maintenance helps in keeping the batteries in good condition.

By leveraging these features, the 12K LUXPower Inverter ensures that the batteries are maintained in optimal conditions, thereby extending their lifespan and providing reliable performance for years.