Battery Equivalents and Replacements

Battery Operated Heater - Can a Battery Power a Tent or RV Heater?

Space heaters are commonly used for heating tents, RVs, offices, rooms, cars, and even homes and apartments. They directly convert chemical or electrical energy into heat, warming up the desired area. Since space heaters directly convert chemical energy into heat, they are simple, reliable, and rather affordable, but also they are not as efficient as, for example, Air Conditioning units.

Battery-operated heaters can be of great help when camping or being off-the-grid by keeping You warm during long, cold days and nights. Right? Well, things are not that simple ...

Updated: January 31, 2022.

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Types of Space Heaters

Space heaters differ in size, output power, construction, etc. but most importantly, they differ in the energy source they use, which they convert into heat. Commonly, space heaters may be:

- electric space heaters,

- propane/natural gas space heaters,

- gas/diesel/kerosene space heaters, etc.

Space heaters that burn fuel like propane, natural gas, gas (gasoline, petrol), diesel, and similar fuels convert chemical energy into heat and can easily heat up tents, RVs, log cabins, etc.

However, such heaters use oxygen from the area they heat up and can be very dangerous, even deadly - modern space heaters come with safety features like low oxygen sensors, carbon monoxide sensors, position sensors, and similar, but ...

IMHO, the author of this article would never recommend using a space heater that uses some kind of fuel and oxygen as an indoor heater. EOD.

If You have to warm up a tent, RV, car, or some similar indoor area, go for an electric heater or, if present, use an AC unit.

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However, AC units and electric space heaters require plenty of electric energy, which can be a problem if You are off-the-grid.

Electric Space Heater vs AC Unit

When trying to heat up an area, one needs to convert some form of energy into heat.

Electric space heaters convert electric energy directly into heat - they are reliable and simple, but not very efficient.

Electric space heaters convert 1Wh of electric energy into 1Wh of thermal energy.

So, 1Wh of electric energy directly converted into heat equals ~3.412 BTU of heat.

Air Conditioning (AC) units feature heat pumps that 'pump the heat' (hence the name) from surrounding/outside air into the heated area, thus operating much more efficiently than common space electric heaters.

Most RVs come with AC units in the 7000-15000 BTU range, requiring approximately 900-1900 Running Watts and 1700 - 2900 Starting Watts. For example:

- RV Air Conditioner 7.000 BTU/h: 900 Running Watts, 1700 Starting Watts → ~7.8 BTU per 1 Wh,

- RV Air Conditioner 10.000 BTU/h: 1200 Running Watts, 2000 Starting Watts, → ~8.3 BTU per 1 Wh,

- RV Air Conditioner 13.500 BTU/h: 1600 Running Watts, 2500 Starting Watts, → ~8.4 BTU per 1 Wh,

- RV Air Conditioner 15.000 BTU/h: 1700 Running Watts, 2700 Starting Watts, → ~8.8 BTU per 1 Wh.

Over time, air conditioning units are improved and their efficiency can only increase.

So, if You are in RV and you can choose to power a space heater OR AC unit, go for the AC unit since they will heat up the area much better while using the same energy/power.

For more about this topic, feel free to check our Will a 2000-Watt Generator Run an Air Conditioner? and Watts to BTU and BTU to Watts Conversions articles.

Battery Powered Electric Space Heaters

If the batteries can be used for powering even cars, they should be able to power space heaters as well, right? Yes, if the battery is large enough.

Car 12V Battery Powered Heaters

One of the very interesting battery-powered heater applications is car 12V battery heaters which are powered using car cigarette light adapters and are limited to ~120W when the engine is off and to ~140-150W when the engine is turned on.

Such battery heaters are used for quick defrosting of windows and for quick warming up of car cabins, while the engine is still cold.

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Another application of car 12V battery heaters is that they can be used as fan-only during hot days.

However, as space heaters, car 12V battery heaters are rather limited.

For example, a 12V 10Amps car 12V battery heater features 120 watts, which is equivalent to ~410 BTU/hr - and this is not much.

Also, car 12V battery heaters discharge the car's battery at a rate of ~10 Ah/h and after just a few hours they can discharge the battery almost completely.

So, in order to warm up your tent or RV, you need a stronger space heater, powered by either a larger battery or some other device.

120V AC Electric Heaters

120V AC electric heaters vary in size, power, construction, and other features, but generally, they are rated between 500 and 2000 watts, which is equivalent to ~1700 - 6800 BTU/hr.

This amount of heat is more than enough to warm up tents, RVs, log cabins, and similar areas.

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The only problem is where one can get that amount of power over a longer period of time - with AC power present, that is not a problem, but when relying only on batteries, this can be a problem.

12V Battery + Power Inverter

Energy stored in batteries may be converted into 120V AC power using power inverters. However, energy in batteries is limited, even when larger batteries are used.

For example, Odyssey 31M-PC2150 AGM dual purpose 12V 100Ah lead-acid battery is able to provide 835 watts for 1 (one) hour.

If the power inverter with 85% efficiency is used, then that battery can power a ~700 W (~2400 BTU/hr) for one hour. And that is a premium 12V 100Ah battery that weighs 77.8 lbs (35.3 kg) - a little bit too much for 1 hour of heating.

For more about these batteries, feel free to check our How Long Will a 100 Amp Hour Battery Last? article.

In order to decrease the weight of the battery (or battery pack), one can go for deep cycle lithium batteries or to keep things simple, for lithium battery-powered portable power stations.

But, if the user has an RV battery pack consisting of, for example, four Ampere Time 12V 300Ah lithium batteries (Amazon link, link opens in the new window), such battery pack can provide 1800W for 8 hours constantly.

And 1800W is a lot - if the RV has a power inverter with 85% efficiency, such battery pack can provide ~1500W for 8 hours, which is enough to power:

- 1500W space heater → ~5100 BTU/h, or

- 1500W AC unit → ~12500 BTU/h.

Also, don't forget that the power inverter acts like a small space heater - a power inverter with 85% efficiency that provides ~1500 output Watts acts like a small ~225W (~767 BTU/h) battery-powered space heater.

Portable Power Stations

Portable power stations are a convenient source of electric energy - they store energy in onboard lithium batteries and convert it to electricity via built-in power inverters.

During operation, power stations do not emit any fumes and can be used indoors.

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However, power stations also suffer from the limited amount of energy stored in the battery - for example, one of the most popular models, Jackery Explorer 1000 stores ~1000 Wh of energy, and with 80% efficiency power inverter may power 800 W (~2700 BTU/hr) electric heater for up to one hour, which is not bad for ~22 pounds (~10 kg) device.

However, in order to use the 500-2000W electric heater for a longer period of time (overnight, for example), when being completely off-the-grid, the solution is either using a large battery pack (for example, 25kVAh) or using portable power generators.

Portable Inverter Power Generators

Portable power generators convert the chemical energy of the fuel into electric energy, which is then converted into heat by an electric heater.

Power generators require oxygen for operation and should be used only outdoors - never, but really never operate them indoors, regardless of 'how good' ventilation is, or 'how many' windows are open or similar. Power generators also produce carbon monoxide (CO) which is an odorless gas that easily kills humans and animals - if used indoors ...

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One of the most popular classes of portable inverter generators are 2000W generators - they are well designed and balanced units, offering plenty of power, while still being relatively lightweight and compact.

The following comparison chart lists some of the best quietest portable generators suitable for camping, tailgating, in emergencies, and similar:

Model

Running Watts

Starting Watts

Runtime Noise

Receptacle

Review

A-iPower SUA2300i

1800W

2300W

6.5h @50% 52 dB @25%
58 dB @50%

AC: 120V 20A 5-20R, 120V 30A L5-30R; DC: 12V 8.3A, USB 5V

-

Champion 2000W Model #100402

2000/1800W

1600/1440W

11h @25% 53 dB @25%

AC: 20A 120V 5-20R Duplex; DC: 12V 8A

-

Champion 2000W Model #100692

1700W

2000W

11.5h @25% 53 dB @25%

AC: 20A 120V 5-20R Duplex; DC: 12V 

-

Energizer eZV2000P

1600W

2000W

11h @25% 50 dB @25%
56 dB @75%
60 dB @100%

AC: 20A 120V 5-20R Duplex; DC: 12V 5A

-

Generac iQ3500

3000W

3500W

8.9h @50%
14.1 @25%
45* dB

AC: 120V 20A Duplex 5-20R, 120V 30A L5-30R; DC: two USB ports (5V/2.1A, 5V/1A)

Review

Honda EU2000i

1600W

2000W

8h @25% 50 dB @25%

AC: 20A 120V Duplex; DC: 12V

-

Honda EU2200i

1800W

2200W

3.2h @100%
8.1h @25%
48 dB @25%
57 dB @100%

AC: 20A 120V Duplex; DC: 12V 100W (8.3 Amps)

Review

Honda EU3000IS

2800W

3000W

20h @25% 50 dB @25%

AC: 120V 20A Duplex, 120V 30A L5-30R

-

WEN 56203i

1700W

2000W

10.8h @25%

7h @25%

51 dB @25%

AC: 2x NEMA 5-20R; DC: 12V (8.3A), 2x USB 5V (1A, 2.1A)

Review

WEN 56235i

1900W

2350W

10.5h @25% 51 dB @25%

AC: 15A 120V NEMA 5-20R Duplex; DC: 12V, USB 5V (2.1A, 1A)

-

Westinghouse iGen2600

2200W

2600W

10h @25% 52 dB @25%

AC: 20A 120V Duplex; DC: 12V, 2x USB 5V

Review

Westinghouse iGen4500

3700W

4500W

18h @25% 52 dB @25%

AC: 120V 20A 5-20R Duplex, 120V 30A TT-30R; 2x USB 5.0V (2.1, 1.0 A)

Review

Yamaha EF2000iSv2

1600W

2000W

10.5h @25% 51.5 dB @25%

AC: 120V Duplex; DC: 12V 8A

-

Yamaha EF2400iSHC

2000W

2400W

8.6h @25% 53 dB @25%

AC: 120V Duplex; DC: 12V 8A

-

Note: Amazon affiliate links ('Model' Column) open in the new windows, feel free to check them for the most up-to-date offers and prices.

For more about these units, feel free to check our Best Portable Quietest Generator - For Camping, Tailgating, in Emergencies, etc. and What Can You Run on a 2000 Watt Generator? articles.

One of the quietest models is Honda EU2200i, although it comes with a very nice price tag.

Honda EU2200i features 1800 Running Watts and 2200 Starting Watts and can easily power electric heaters up to 1500-1800 watts. Also, it can operate on a single gas tank for up to 8.1 hours @25% load (450 watts), or 3.2 hours @100% load (1800W).

So, if You want to power a ~500W (~1700 BTU/hr) heater with Honda EU2200i, You may expect almost 8 hours of constant operation on a single fuel tank. Or if You want to power a 1700-1800W (5800-6140 BTU/hr) heater with Honda EU2200i, You may expect slightly more than 3 hours of operation.

If the combination of a battery pack and a power inverter with 80% efficiency is used for the same task, one would need a battery pack with an actual capacity of ~5000 Wh (12V 416 Ah, 24V 208 Ah, or similar) or ~6750 Wh (12V 560 Ah, 24V 280 Ah, or similar).

A 5000Wh capacity can be achieved using two Group 8D 12V 230-250Ah lead-acid (AGM or Gel-Cell) batteries or two 12V 210+Ah lithium batteries.

However, while Honda EU2200i with full tank weighs ~47 pounds (~21.3 kg), two large lithium batteries, for example, GreenLiFE GL260 (12V 260 Ah) weigh 160 pounds (72.48 kg) both, two Group 8D AGM batteries, for example, Mighty Max ML8D weigh 318 pounds (144 kg) both - and that is a lot of weight to carry around.

But, lithium batteries are getting cheaper and cheaper, and if the larger battery pack is required, then lithium batteries are the way to go - for more information about this topic, feel free to check our What Is The Best 12 Volt Lithium Battery? article.

Such a large battery pack can be recharged using mains power, solar panels, or, of course, portable inverter power generators.

Battery Powered Space Heaters Frequently Asked Questions (FAQ)

Here are some of the most common Frequently Asked Questions about battery-operated space heaters and AC units.

Are there any heaters that run on batteries?

Small glove-size heaters that are used to keep the fingers warm can run for a longer time on relatively small batteries.

But, battery-powered space heaters require large batteries that can come rather costly.

Are there heaters that don't require electricity?

Yes, there are space heaters that use gas, propane, natural gas, diesel, kerosene, and similar fuels and they don't need electricity to provide energy. However, most of such heaters have sensors and lighters that require a very small amount of electricity, which is usually provided by a few AA or similar batteries.

How can I heat a small room without electricity?

Space heaters that use gas, propane, diesel, and similar fuels can be used to heat up a small room without electricity. However, such space heaters use oxygen from the air and are not the safest space heaters since they require rooms to be ventilated regularly.

Can a portable battery power a heater?

Yes, but only for a very limited amount of time.

Is there such thing as a battery-powered heater?

Generally no. But, an AC space heater can be powered using a power inverter and a large enough deep cycle battery.

Can you run a space heater on a portable power station?

Yes, but again, for a very limited period of time, depending on the size of the power station's battery and the size of the space heater.


Long Story Short: Battery-powered space heaters for tents and RVs are still far away from the commercial application - simply, current battery technology does not offer means of storing enough energy for any decent-size electric heater to operate for at least 5-10 hours continuously.

But, if You have enough space in your RV, an RV home battery pack consisting of 3-5 12V 200-400Ah lithium batteries can provide enough energy for an RV AC unit to keep the RV warm all night long.

On the other hand, if You have the need to keep your RV or tent warm overnight and a large battery pack is not an option, your next best option is to use a quiet portable inverter generator to produce electric energy and an AC unit or electric space heater to produce heat.

Again - never, but really never operate internal combustion engines (power generators, for example) indoors...