A Detailed Explanation of “For how Long Can a Solar Generator Run?”

How Long Can a Solar Generator Run

Before buying a solar generator, you need to know what size will suit your needs. There are so many different options to choose from in the market, that knowing which one is right for you can be quite overwhelming.

Take Bluetti, for example, we already sell about 9 different solar generators, all with different capacities. So, how do you know which size solar generator is right for you? In this article, we will explain How long can a solar generator run?

How long can a solar generator run?

When someone is looking for a solar generator, one of the most crucial points is to know how long solar-powered generators last? For this reason, here in this article, you will have a detailed explanation of “for how long can a solar generator run?”. Let’s find out in this article.

The portable solar energy generators are apparent evidence of the transformation of energy usage to numerous renewable energy fields. You can run lights, and fans, heat the water, or your room for survival with this clean energy during emergencies such as power outages.

Let’s find out how long can a solar generator run, find out the better solar power or generator, the longevity of solar generator last, and its uses in different appliances.

What is the best off-grid generator: A portable solar power system?

Consider your area goes off-grid due to a thunderstorm. Suppose the solar generator battery drains within hours, and there isn’t sufficient sunlight to charge the battery.

In that case, you’ll have rotten foods in the fridge.

A solar generator is merely a rechargeable battery but revolutionary for its-

Lightweight / Maximum portability

Solar power generators are a compact system without requiring any roof-mounted solar photovoltaic (PV) panels.


The multiple input options (to recharge the battery) and multiple output options (AC plug, USB, carport) of solar-powered generators make them a perfect companion for traveling a long distance (in RV or otherwise), camping, boating, or fishing in lakes.

How do I choose a solar generator: What is the most efficient generator?

Look for the solar generator rating. It is a measurement of power (maximum watts) that the solar powered generator can deliver over an ideal time.

The wattage (max) of the inverter plays a significant role in your solar generator as most electronic devices employ AC.

Manufacturers use inverter rating as solar portable generator rating since the inverter rating is the highest limit of how much power the AC appliances can pull.

You do not need a massive inverter but a compatible one with your solar generator battery.

A charge controller of MPPT (maximum power point tracking) specification, enables the solar generator to be portable and more efficient.

Technical specification

Photovoltaic (PV) conversion The solar panels convert sunlight (photons) into energy.
Energy storage A charge controller regulates the flow of generated energy from the solar cells to batteries.
AC to DC transformation The battery-stored energy runs across an inverter. It transforms direct current (DC) into alternating current (AC).

⦁ If the rating (capacity) of a particular solar generator unit is 2000 watts and the capacity of the battery is 100 Ah (12V), it means

⦁ The unit can run (uninterruptedly)
an appliance of 2000 watts
Or, multiple devices of 2000 watts

⦁ The 100 Ah battery of 12 V can supply
100 amperes for 1 hour,
Or, 1 ampere for 100 hours, etc.

These ratings and specifications are just an initial screening to determine the most efficient solar portable generator for your needs. But they don’t make it quite clear whether I require a heavy-duty solar generator or not, do they?

How long does a solar generator last (run time)?

Now that you are familiar with the efficacy of solar generators, let me start the central piece: A detailed explanation of “For how long can a solar generator run?”

. Run time: A measurement of how long a portable solar energy generator functions to power electronic appliances by the recharged battery.

Run time (max hours) = The capacity of the solar generator (watt-hours) / Power required for the device (watts)

Usable watt-hours: Usable watt-hours of a solar power generator is the most important indicator of how long does a solar generator lasts.

Volts x Ah = watt-hours

Your specified electrical equipment may require an uninterrupted supply of power that might deplete battery charge in no time.

But draining 100% of any conventional batteries reduces lifespan and increases the rate of battery damage.

Usable watt-hours (recommended)
Lithium batteries 90 % of battery capacity (watt-hours)
Lead-acid batteries 60 % of battery capacity (watt-hours)

Usable watt-hours for a 100 Ah lead-acid battery of 12 V becomes, = Volts x Ah x 60 %
= 12 x 100 x 60/100
= 720

Incandescent bulbs

⦁ You can run
seven 100-watt bulbs for an hour
Or, you can run fourteen 100-watt bulbs for 30 minutes.

CFL (Compact fluorescent lamps) bulbs

⦁ Your solar powered generator can power
two 25-watt bulbs for 14.4 hours

⦁ Conversely, the number of CFL bulbs the solar generator can power for 14.4 hours on your 100 Ah, 12V battery
= 720 watt-hours / (14.4 hours x 25 watts)
= 2 bulbs.

LED (Light-emitting diode) bulbs

⦁ Likewise, your solar generator can power nine 16-watt LED bulbs for 5 hours.

A solar portable generator’s efficiency comes down to your energy requirement and battery capacity (size and type).

⦁ You can’t expect a 50 watt solar generator to backup power at home unless you want to sit idle in the dark!

⦁ A heavy-duty solar generator of at least 4500 usable watt-hours and inverter rating beyond 3000w can deliver adequate emergency backup power.

⦁ A battery backup of such a portable power station can run electrical loads such as TV, fridge, microwave, etc., for several days depending on the appliance’s required power (watts).

How long will a solar generator last, and for how many appliances?

A powerful solar generator for just charging the smartphones now and then would render your heavy-duty solar generator quite useless. You should preferably have a clear concept of

⦁ How many appliances you can run on a solar generator unit for a given time and

⦁ How many hours you can run a solar generator unit for a definitive number of appliances.

Coffee maker

⦁ Now, you want to make coffee in your 1200W coffee maker with a 100 Ah, 12V solar powered generator of 720 usable watt-hours.

The run time (minimum) should be 0.6 (720/1200) hours or 36 minutes.


⦁ How many cups of tea can you heat for (2 minutes each) in your microwave of 1500W?
(720/1500) x (60/2) = 14.4 or 14 cups

How can a solar generator run an air conditioner & for how long?

One of the biggest energy consumers in households is an air conditioner unit.


Three solar panels of 200 watts A battery of 1200 watts Charging time 2 hours A room of 250 sq. ft. 6,000 BTU air conditioner

⦁ Your solar PV panels get one-fourth of the day (6 hours) to power themselves.

You’ve three 200 watt solar panels (they’ll make 600 watts in an hour and a total of 3600 watts in 6 hours in a day; 600×6=3600).

⦁ The solar panels will charge the battery in 2 hours (panels will produce 1200 watts; 600×2=1200), which will run during the night.

The rest of 3600 watts (3600-1200=2400 watts) will run items during the day.

⦁ You need to know how many watts (power) does your BTU (British thermal unit) air conditioner uses.

A 6,000 BTU (for a room size of 250 square ft) AC uses 500 – 750 watts of power.

⦁ But, if you’ve only one 200 watt solar panel, it’ll make 1,200 watts in 6 hours.

That means the battery will not have enough power for usage during the night as the air conditioner might run during the day.

⦁ Again, an air conditioner requires 2x the continuous power for the start-up.

If the device operates at 500w, it will need 1000 watts to start the unit. So, your inverter rating must be 1000 watts, to the least.

⦁ So, a solar generator of the above specifications can power a 6,000 BTU air conditioner (window unit) for 30 minutes (approximately) during the night.


I hope this article has given every single piece of information about How long can a solar generator run? It depends on your chosen electrical appliances’ energy consumption and the usable watt-hours that your solar generator unit can provide.

The calculation becomes crucial if you need to run lights & fans or ventilators throughout the night with a solar energy generator.

You do not need to refuel your solar generator, and it is maintenance-free among many other countless such properties.

The watt-rating of electrical load times the number of that unit for each appliance will give the total power (watts) required.

In this article, a detailed explanation of “for how long can a solar generator run?” was given.

In short, dividing the usable watt-hours of the solar power generator by the watts required will give you an idea of how long can a solar generator run.

Summary: 2 key points to remember when you look for a solar generator

⦁ Battery & inverter rating

An efficient solar generator battery rating (usable watt-hours) should be 1.5-2 times the inverter raring.

Low inverter rating confines the output of the solar generator.

Inverters of higher rating give the solar generator unit uninterrupted powering (AC) ability.

⦁ Battery & charge controller type

You can drain lithium batteries to 10 % of the rated capacity.

The solar generator’s MPPT charge controller increases power output and thus the recharging speed of the battery.


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