How Long Does a 10kWh Battery Last? Runtime for Your Home and Appliances
Short answer
A 10 kilowatt hour battery gives you about 9 kWh of usable energy, so it runs a steady 1 kW load for about 9 hours, or 8 hours once inverter losses are counted. That covers a fridge, lights, Wi-Fi and a TV for one to two days, but only about 7 hours of an average US home. About 7 residential solar panels can recharge it on a typical sunny day.
A 10 kilowatt hour battery is one of the most common sizes for home backup and solar storage. It is big enough to keep the essentials running through an overnight outage, small enough to fit on a garage wall, and a good building block if you want to stack more capacity later.
The number on the label is not the number of hours it lasts, though. This guide explains how much of the 10 kWh you can actually use, how to work out runtime for any load, how long common appliances run, how many panels recharge it and what a 10 kWh battery costs in late 2026.
How much of a 10 kWh battery can you actually use?
Battery makers quote two figures. Nominal capacity is the total energy the cells hold. Usable capacity is what the battery management system lets you draw, because it keeps a reserve at the top and bottom to protect the cells. Most lithium home batteries allow about 90% of nominal, and this site uses 90% as its standard assumption.
The energy then passes through an inverter that turns the battery’s DC into the AC your outlets use. Inverters typically lose about 5% to 10% along the way, and a little more at very light loads.
Example: 10 kWh × 0.90 × 0.90 to 0.95 = 8.1 to 8.6 kWh
So a 10 kWh solar battery delivers roughly 8 to 9 kWh to your appliances.
How long does a 10 kilowatt hour battery last?
Runtime is energy divided by power. Add up the watts of everything running at the same time, convert to kilowatts, and divide the usable capacity by that load.
Example: 9 kWh ÷ 1 kW = 9 hours
The table shows runtime at common household loads. Real homes rarely draw a flat load, so treat these as worst-case figures. The first column uses the 9 kWh usable figure. The second column also takes off 10% for inverter losses, which is the safer number for planning.
| Continuous load | Runtime on 9 kWh | Runtime after inverter losses (8.1 kWh) | What the load looks like |
|---|---|---|---|
| 0.5 kW | 18 hours | about 16 hours | Fridge, lights, Wi-Fi, TV, phone charging |
| 1 kW | 9 hours | about 8 hours | Essentials plus a well pump or furnace fan |
| 2 kW | 4.5 hours | about 4 hours | Essentials plus a window AC and cooking |
| 3 kW | 3 hours | about 2.7 hours | A small central AC running steadily |
| 5 kW | 1.8 hours | about 1.6 hours | Electric oven, AC and dryer together |
For a runtime based on your own appliance list, the battery backup calculator does the sums for you.
How long will a 10 kWh battery run common appliances?
The next table runs each appliance on its own from 9 kWh of usable energy. Wattages are typical running values. Your appliances may differ, so check the label or a plug-in energy meter.
| Appliance | Typical power | Runtime on 9 kWh |
|---|---|---|
| Refrigerator (about 1.5 kWh a day) | about 60 W average, 150 W running | about 6 days |
| LED lights, 10 bulbs at 9 W | 90 W | 100 hours |
| Wi-Fi router and modem | 20 W | 450 hours (about 19 days) |
| 55 inch LED TV | 100 W | 90 hours |
| Well pump, 1 hp | 1,000 W running | 9 hours of pumping |
| Window AC, 8,000 to 10,000 BTU | 900 W | 10 hours of compressor time |
| Central AC, 3 ton | 3,500 W | about 2.6 hours |
| Space heater | 1,500 W | 6 hours |
| EV charging, Level 1 (120 V) | 1,400 W | about 6.4 hours |
| EV charging, Level 2 (240 V, 30 A) | 7,200 W | about 1.25 hours |
Two loads stand out. Heating and cooling drain a 10 kWh battery in hours, and EV charging empties it in about an hour at Level 2. At a typical 3 to 4 miles per kWh, a full 9 kWh adds only about 27 to 36 miles of range, so most owners keep the car off the backup circuit.
Can a 10 kWh battery power a whole house during an outage?
Only for a short time. The average US home buys about 10,800 kWh of electricity a year according to the U.S. Energy Information Administration, which is close to 30 kWh a day, or an average draw of about 1.25 kW. At that rate, 9 kWh lasts about 7 hours, and less on a hot afternoon with the air conditioning running.
Most 10 kWh systems are therefore set up to back up an essentials panel: a small subpanel with the circuits you cannot do without. Here is a realistic outage day for a home with gas heat:
| Essential load | Use per day | Energy per day |
|---|---|---|
| Refrigerator | 24 hours, cycling | 1.50 kWh |
| LED lights, 90 W | 5 hours | 0.45 kWh |
| Wi-Fi router and modem, 20 W | 24 hours | 0.48 kWh |
| TV, 100 W | 3 hours | 0.30 kWh |
| Laptop and phone charging | through the day | 0.30 kWh |
| Well pump, 1,000 W | 1 hour | 1.00 kWh |
| Gas furnace blower, 300 W | 6 hours | 1.80 kWh |
| Total | about 5.8 kWh |
At 5.8 kWh a day, 9 kWh lasts about a day and a half. Drop the furnace blower in mild weather and the same battery stretches past two days. With solar panels recharging it each morning, an essentials setup can run through a multi-day outage as long as the sun cooperates.
What is the difference between kW and kWh on a battery?
Energy (kWh) tells you how long a battery lasts. Power (kW) tells you how much it can run at once. A 10 kWh battery paired with an inverter rated for 5 kW continuous cannot run a 3.5 kW central AC and a 4 kW electric oven together, even when the battery is full. The inverter will trip or shut down on overload.
Home batteries in this size range are often paired with inverters of roughly 5 to 7.6 kW continuous, with a higher surge rating for a few seconds. Motor loads such as well pumps and AC compressors can draw two to three times their running watts at startup, so check both numbers before you choose which circuits to back up. The inverter size calculator adds up running and surge watts for your appliance list.
How many solar panels does it take to charge a 10 kWh battery?
Using this site’s standard assumptions of 430 W panels, 4.5 peak sun hours and 80% system efficiency, each panel makes about 1.55 kWh a day.
Example: 10 kWh ÷ (0.43 kW × 4.5 × 0.8) = 10 ÷ 1.55 = 6.5, so about 7 panels
Seven 430 W panels make an array of about 3 kW. Sizing to the full 10 kWh rather than the 9 kWh usable leaves a margin for charging losses. That array only refills the battery, though. If you also want the panels to run the house during the day, you need more. Check your local sun hours and panel count with the how many solar panels calculator.
How many 10 kWh batteries does a typical home need?
It depends on what you want the batteries to do. Our guide to how much battery storage you need walks through the full sizing method; here is how it works out with 10 kWh units:
- Overnight essentials or short outages: one 10 kWh battery is usually enough.
- Shifting evening and overnight use to stored solar: if 40% to 60% of a 30 kWh day happens after sunset, you need 12 to 18 kWh usable, which means two batteries.
- A full day of whole-home backup: 30 kWh ÷ 9 kWh usable = 3.3, so plan on four batteries, or 40 kWh nominal.
To recharge 30 kWh a day you would need about 30 ÷ 1.55 = 19.4, or roughly 20 panels at the same assumptions. The battery bank calculator sizes storage from your daily use and the days of backup you want.
How many amp hours is a 10 kWh battery?
Amp hours depend on voltage. Divide watt hours by the battery voltage:
Example: 10,000 Wh ÷ 48 V = 208 Ah
| System voltage | Amp hours for 10 kWh | Typical use |
|---|---|---|
| 12 V (12.8 V LiFePO4) | 833 Ah (781 Ah) | RVs, vans, small cabins |
| 24 V | 417 Ah | Larger off-grid cabins |
| 48 V (51.2 V LiFePO4) | 208 Ah (195 Ah) | Home backup and off-grid homes |
That is why most home batteries run at 48 V or higher: lower current means thinner cables and smaller fuses. A common DIY setup is two 51.2 V, 100 Ah server-rack modules, which make 10.24 kWh. Convert your own figures with the Ah to kWh converter or go the other way with the kWh to Ah converter.
LiFePO4 vs NMC: which chemistry lasts longer?
Most home batteries now use one of two lithium chemistries:
- Lithium iron phosphate (LiFePO4 or LFP): heavier and slightly larger, but very stable and long lived. Spec sheets for home LFP batteries commonly list about 6,000 cycles before capacity falls to around 70% to 80%.
- Nickel manganese cobalt (NMC): more compact, but typically rated for fewer cycles, often in the range of 2,000 to 4,000, and more sensitive to heat.
How many years will a 10 kWh battery last?
At one full cycle a day, 6,000 cycles works out to about 16 years. In practice, calendar aging, heat and high charge levels mean most homeowners should plan on about 10 to 15 years. Warranties are commonly 10 years, usually with a guarantee of 60% to 70% of original capacity at the end, and some also cap the total energy you can cycle through the battery. Read the warranty for both limits.
How much does a 10 kWh battery cost?
These are typical US ranges in late 2026, before any incentives:
- Professionally installed home battery: about $8,000 to $14,000 for 10 kWh, including the inverter or gateway, labor and permits. EnergySage quote data shows a typical system price that works out to a little under $1,200 per kWh, with wide variation by brand and state.
- DIY battery modules: about $1,500 to $3,500 for 10 kWh of 48 V LFP server-rack or wall-mount batteries.
- DIY hybrid inverter and parts: add roughly $1,000 to $3,000 for the inverter, breakers, cables and mounting. Local codes usually require a permit and inspection for any battery tied to home wiring.
The 30% federal residential clean energy credit ended for homeowner-owned systems installed after December 31, 2025, so do not count on it in your budget.
Example: $10,000 ÷ (6,000 × 9 kWh) = $10,000 ÷ 54,000 kWh = about $0.19 per kWh
That figure assumes the battery reaches its full rated cycles. Compare it with your electricity rate to judge whether daily cycling pays off, or use the home battery savings calculator with your own rates.
Frequently asked questions
How long will a 10 kWh battery run a refrigerator?
A modern refrigerator uses about 1 to 2 kWh a day, so 9 kWh of usable energy runs it alone for roughly 4 to 9 days. At a typical 1.5 kWh a day, that is about 6 days. The inverter must handle the compressor’s startup surge, which is easy for any home battery inverter.
Can a 10 kWh battery run central air conditioning?
Yes, but not for long. A 3 ton central AC draws about 3.5 kW while running, so 9 kWh lasts about 2.5 hours of compressor time. The inverter also needs enough continuous and surge power to start the compressor. Many owners back up a window AC or a mini split instead.
Is 10 kWh of battery storage enough for a house?
It is enough for essentials such as a fridge, lights, Wi-Fi and a well pump for about one to two days. It is not enough for a whole home, since the average US house uses close to 30 kWh a day. Full-day whole-home backup needs about four 10 kWh batteries.
How many solar panels do I need to charge a 10 kWh battery?
About 7 panels rated 430 W, assuming 4.5 peak sun hours and 80% system efficiency. Each panel makes about 1.55 kWh a day, and 10 ÷ 1.55 is about 6.5. Sunnier locations need fewer panels and cloudy ones need more.
How long does a 10 kWh lithium battery last in years?
A LiFePO4 home battery rated for about 6,000 cycles typically lasts 10 to 15 years in real use, and most come with a 10 year warranty that guarantees 60% to 70% of capacity at the end. Heat and keeping the battery full all the time shorten its life.
