Grid Down Redoubt ESS Logo

Grid Down Redoubtis an Industry Leading, Advanced, Safe, Easy to Install, Grid-Tied & Off-Grid Capable, Lightning & EMP Protected Energy Storage System (ESS) that comes with a 25 Year Warranty.


Grid Down Redoubt Backup Battery Energy Storage System EMP Protection EMP Shield Solar Energy 40.5 kWh

Looking for a larger or smaller system? See all of our systems HERE

Need solar panels? Get USA made Mission Solar panels HERE


● Lion Energy Sanctuary – Energy Storage System with a 40.5 kWh Battery Storage Capacity.
   – 1x Hybrid Inverter (12kW Solar/DC Input, 8-14kW AC Output, 90A Grid Passthrough)
   – 3x 13.5 kWh LiFePO4 Batteries (40.5 kWh Total Capacity)
● 25 Year Industry Leading Warranty on the Lion Sanctuary ESS.
● Complete EMP Shield Electromagnetic Pulse and Lightning Protection for Your Entire Home and the Grid Down Redoubt System. EMP Shields Included are:
   – 2x DC EMP Shields (Protects 2x Solar Arrays)
   – 2x AC EMP Shields (Protects Home + Redoubt)
● EMP Shield Protection is Listed by the Department of Homeland Security in their EMP Resilience Report.
● 10 Year EMP Shield Warranty with 100% Guaranteed Lightning Protection Backed by a $25,000 Insurance Policy.
● Eligible for 30% US Tax Rebate (See Below for Details)*
● Free Shipping (Within the Continental US). Ships Within 7-18 Business Days.

$30,799 $25,499

Paypal Credit 0% Interest free credit grid down

Looking for a larger or smaller system? See all of our systems HERE

Need solar panels? Get USA made Mission Solar panels HERE

The Grid Down Redoubt is one of the worlds most advanced, modular, easy to install and comprehensive energy storage systems on the market. Based around the Sanctuary Energy Storage System by Lion Energy, our Redoubt takes energy storage a step further by including advanced EMP and lightning protection. Backed by an industry leading 25 year warranty, the Grid Down Redoubt is on average 20%+ more affordable than most other comparable energy storage systems. With a focus on safety, our Grid Down Redoubt provides industry leading safety certification and compliance. Our systems feature more storage capacity and inverter capability than most other energy storage systems on the market in this class. For anyone looking to purchase an energy storage system, we challenge you to shop around. After you do your research you will find that the Grid Down Redoubt's features, warranty, safety, protection, and price make it one of the best energy storage systems in the industry. 

Need Help? We've Got You Covered!

Grid Down Redoubt ESS Selection Tool

Our Grid Down Redoubt Selection Tool will help you calculate the total amount of energy your home could potentially use (called the load) and then tell you which Grid Down Redoubt system is best for you. 

Grid Down Redoubt ESS battery life calculator

Our Grid Down Redoubt Battery Life Calculator is an incredibly easy to use tool that will tell you how long your Redoubt battery may last based on the amount of energy you select to be used per day. 

Solar Panel Charge Time Calculator Grid Down Redoubt

One question we get asked a lot is: If I have solar panels, how long will it take to charge my Redoubt system? With our new calculator, you can estimate just how long it will take to charge your system using solar panels.

Grid Down Redoubt 30% Tax Credit on Energy Storage Systems Inflation Reduction Act

Energy Storage Systems

May Qualify for a

30% Tax Credit

With the Inflation Reduction Act, battery storage installed in 2023 can qualify* for the 30% federal tax credit, even if they aren’t attached to solar panels. This may allow you to save thousands and is a key to unlocking affordable, clean energy.

*To qualify, the taxpayer must be the owner of the battery system, must have taxable income, and the system must be installed at the taxpayer’s residence. It can only be claimed on the original installation of the system, and the battery must be as least 3 kilowatt-hours (kWh) in size. Other conditions may apply to your personal situation. Please refer to a tax expert in your area. Source: >

Unlock Savings, Tax Benefits, and Impressive Potential Return on Investment!

Maximize your return on investment with an energy storage system from Grid Down. Our Grid Down energy storage system allows you to leverage the 30% tax credit, dramatically reduce your electrical bill (for grid-tied applications) and potentially increase the value of your home.

Purchasing a Grid Down Redoubt is a strategic investment that can bring significant financial rewards and peace of mind. Grid Down systems provide the security of knowing you’ll always have power when you need it, in any situation. 

ROI Calculator

Solar ROI Calculator

30% Federal Tax Credit
$ 15,508
Estimated Annual Electricity Savings
$ 4,652
Cost After Incentives & Savings
$ 31,534
Estimated Home Value Increase
$ 72,372

These are estimates based on the national averages.

Please use these as strictly estimates and not exact amounts.

Grid Down Redoubt 40.5 kWh Energy Storage System


Grid Down ESS battery backup

Energy Capacity
13.5 kWh per unit (expandable to 81kWH @ 6X batteries)

Backup Power
8 kW-24kW continuous power (8kW per inverter)
14 kW peak (10 secs)

Size and Weight
74.25 in x 18.5 in x 10 in (L x W x D)
375 lbs

DC to AC inverter efficiency: 96%
Round-trip efficiency: 94%
Max solar input: 12 kW

Integrated inverter and system controller
32°F to 86°F
Water and dust resistant

Meets North America safety and EMI standards.
Meets the most stringent safety protocols (UL9540), which includes UL1741 for the inverter and UL1973 for the battery (lithium iron phosphate or LiFePO4).

25 Year Industry Leading Warranty
10 Year EMP Shield Warranty
100% guaranteed lightning protection backed by a $25,000 insurance policy.

Redoubt Charging Options


Grid Down Redoubt Off Grid ESS

Off-Grid is when you are getting power from an alternate energy source like solar panels, generator, wind power, or hydro power. This alternate energy source can be used to charge the Redoubt energy storage system and power your home directly.


Grid Down Redoubt Grid Tied ESS

Grid-Tied is when you are getting power directly from the power grid. With the Grid Down Redoubt, the electrical grid can be used to charge the Redoubt energy storage system and also power your home directly.


Grid Down Redoubt Grid Tied and Off Grid ESS

A combination system is when you are connected to the grid and also getting power from an alternate energy source. With a combination system, you can charge the redoubt from both power sources and also power your home from both power sources.

Basic System Architecture

This figure depicts the basic application of the Grid Down Redoubt System. Power is fed into the system from the power grid, solar power array or generator to have a complete running system.

Grid Down Redoubt Solar Power System Energy Storage System ESS Off Grid

Power in the Palm of Your Hand

Grid Down Redoubt App

Advanced Metrics
Monitor current and past energy usage, turn features and/or products on and off at the touch of a button, and set up custom controls to tailor your Grid Down Redoubt to your needs.

Monitor Current and Past Energy Consumption
See what energy is coming in and going out from both your solar system and Grid Down Redoubt. Look at past energy data by the hour, day, week or month so your system can be more efficient. Make individualized adjustments to create the best experience for yourself.

Set up Personalized Controls
Connect your devices and control the functionality of your Grid Down Redoubt from a distance using Bluetooth Technology. Remotely turn on or off your batteries so you’re not wasting any energy.

Automate & Save
For your Grid Down Redoubt, use the app to automate recharge times to only draw energy from the grid during off-peak hours. Create specific intervals to recharge you Sanctuary batteries, whenever is best for you.

Control Your System
Be ready for a home blackout or a big storm, winterize your RV, or turn your solar generator off or on.

Redoubt Benefits


Accumulate energy when the demand is low and discharge stored energy during peak times, saving money.

Backup Power/

Supply backup power in case of an electrical grid failure until complete power restoration. Save time and money by eliminating downtime.

Renewable Energy

Open the door to inexpensive electricity continuously available to on-grid, off-grid, and hybrid systems.

Power System
Recovery Capability

Based on battery storage, a Redoubt can restart after a total shutdown without using external electricity networks. Recover in the shortest time possible.


In areas where electricity prices fluctuate, energy is purchased at a low price during off-peak periods and sold or used when the price increases.


Immediately react to power interruptions and stabilize the grid. It can also ensure voltage stability, maintaining its level within the specified range.

Better Capabilities. Better Solution.

Grid Down RedoubtTesla
Powerwall 2
Generac PWRcellEcoFlow 2 Delta
Pro + Smart Panel
Bluetti 2*AC500
+4B 300S
Encharge 10
Sonnen Eco10LG Chem RESU10H
Battery ChemistryLiFePO4Li NMCLi NMCLiFePO4LiFePO4LiFePO4LiFePO4Li NMC
Energy Capacity13.5 kWh13.5 kWh9 kWh7.2 kWh18.4 kWh10.5 kWh10 kWh9.3 kWh
Max Load Continuos8 kW5 kW6.7 kW7.2 kW5 kW3.84 kW8 kW5 kW
Max Peak Load14 kW7 kW9 kW7.2 kW10 kW5.7 kW8.5 kW7 kW
Warranty25 Years10 Years10 Years2 Year5 Year5 Years10 Years10 Years
Round Trip Efficiency94%90%96.5%N/AN/A89%81.6%N/A
Life Cycle6,000 @ 90%5,000 @ 96%2,649 @ 80%3,5003,5004,000 @ 70%10,000 @ 90%4,000 @ 95%
Additional Equipment RequiredNoYesYesYesYesYesYesYes
Estimated Price Per Wh (*1)$0.54$0.56$0.75$0.58$0.93$0.69$1.43$0.72

*1 "Watt-hour". Estimate pricing is based off largest configuration system build out and includes - product price, average installation cost, average premit cost, and 30% tax credit (if qualified).

Hybrid Inverter Specs

☀️ PV Input

Max PV Input12kW
MPPT Input Voltage120-500V
Max Input Current12A*4
Max Short Circuit Current15A

🔌 AC Output (On Grid)

Rated Output Power8kVA
Rated Output Current33.3A
Grid Voltage120V/240V Split phase
Grid Frequency (Optional)60Hz
Power Factor Range-0.8~+0.8

⚡️ Battery

Battery Voltage Range40V~60V
Max Charging Current190A
Max Discharging Current190A

📐 System

Ingress ProtectionIP65
Dimensions27.9” H x 16.9” W x 8.7” D
Max Efficiency97.8%

⚠️ Compliance

ULSTD.1741, UL1741 SA, UL1741 SB, CPUC RULE21, SRD-UL- 1741-SA-V1.1, IEEE1547-2003, FCC 15 class-B, UL1699B Arc-Fault Circuit-protection Type 1. 

System Info

🔋 13.5kWh Battery Specs

Battery TypeLithium Iron Phosphate
Voltage Range40 - 55.6 VDC
Capacity13,875.2 Wh
Parallel Capacity41,625.6Wh Max
Quantity3 Batteries Max Per Inverter
Charging Temp. Range / Current32º to 86º F /150A
Discharging Temp. Range-4º to 86º F /160A
Cycles to 90% Depth of Charge6,000
Weight / Dimensions277 lbs. / 39.75” H x 18.5” W x 10” D
ComplianceUL1973, UL9540, UL9540A

⚠︎ Charge Mode

Battery Voltage48VDC (45V - 55.6VDC)
Battery Current190ADC Max
AC Input Voltage240V Split Phase
AC Input Frequency60Hz
AC Input Rated Current33.3AAC
Max AC Input Current33.3AAC
Max AC Input Power8,000W
PV Input Voltage150VDC - 500VDC
MPPT Input Range150VDC - 475VDC
PV Input Current12ADC per MPPT
Max PV Input Power14,000W

⚡️ On-Grid Mode

AC Output Voltage240V Split Phase
AC Output Frequency60Hz
AC Output Rated Current33.3AAC
Max AC Output Current33.3AAC
Max AC Output Power8,000W
AC Output Rated Power8,000W
Max Continuous AC Passthrough90AAC
AC Output Power Factor0.8 leading to 0.8 lagging
Battery Discharge Voltage45V - 55.6VDC
Battery Discharge Current180ADC Max
Battery Discharge Power8500W

☀️ Off-Grid Mode

AC Output Voltage240V Split Phase
AC Output Frequency60Hz
AC Output Rated Current33.3AAC
AC Output Rated Power8,000W
Peak Output Power14000W 10 Seconds
Battery Discharge Voltage45V - 55.6VDC
Max Discharge Current190ADC Max
PV Input Voltage150VDC - 500VOC
MPPT Input Range150VDC - 475VDC
PV Input Current12ADC per MPPT
Max PV Input Power14,000W

About EMP Shield Protection

EMP Protection

All Phases an EMP (E1, E2, & E3)

Solar Flares

Up to 228,000 Amps

Lightning Protection

100% Lightning Guarantee Backed By a $25,000 Insurance Policy

emp shield kansas emerging business of the year
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Featured In

EMP Shield National Security Collaboration Center NSCC
emp shield as seen on fox

Industry Leading 10 Year Warranty

If it fails at anytime during the 10 year limited lifetime warranty, we replace it for $50. No questions asked!

Backed by $25,000 of Insurance

If the device doesn't protect your electronics, we will cover the damage

Surpasses All Military EMP Testing Standards

  • MIL-STD-188-125-1
  • MIL-STD-464C
  • MIL-STD-461-G
  • RS-105 (90,000 Volts)

Listed by the Department of Homeland Security

EMP Shield Has Set New Standards in EMP Protection and is Listed by Homeland Security in their EMP Resilience Report

How Has EMP Shield Been Tested?

Isn't a nuclear explosion required to create an EMP?

The threat of an EMP is the large amount of electricity that is induced into conductors that generate heat and can be destroyed.  There are only a few testing facilities in the world capable of producing the same amount of electricity that an EMP produces. 

EMP Shield has been rigorously tested at the Keystone compliance facility which is a federally approved testing facility that is used to conduct many of today's most advanced and rigorous technological tests. Out testing and evaluations conducted at the facility were documented in depth to show the true ability and durability of the EMP Shield. Below you will find the complete Keystone Compliance testing results of the EMP Shield.


Have a Question?

Contact us via our Contact Us Page or call: 620-412-9978 (MON-FRI / 0800-1700 CST). Customer Service is through our partner EMP Shield which has over 5,000 5-Star reviews.