0 Electricity bill | 0 Noise with Energy Storage System

How Many Hours Can Solar Batteries Work During Power Cuts?

Solar batteries are one of the technologically mature solutions for energy independence and self-sufficiency.

In the past, solar panel systems were used to save electricity bills.

However, with the improvement in quality of life, more and more devices at home that require electricity are also increasing.

For example, intelligent sweeping robots, whole-house intelligent control systems, automatic cooking kitchen utensils electric vehicles, etc.

All of these require a lot of electricity to maintain. This causes the supply of old-fashioned public utility grid power plants to exceed demand, and sudden power outages may occur from time to time.

Solar batteries can operate for 24 hours during a power outage without AC or DC electrical loads running.

Especially during nighttime power outages, your solar panel system will stop working because it has no batteries.

If you add solar batteries, you will not have to worry about power outages or insufficient power generation from the solar panels on rainy days.

So, how long can solar batteries provide power during a power outage?

This question is always inseparable from the following main elements:

1-The load power of the electrical appliance you use

2-Your load during working hours (at night or during a power outage)

3- Battery capacity

4-Power generation from solar panels

PVMars Solar Company summarized the types of solar battery capacity most customers choose and calculated how many hours those batteries could provide power during an outage.

Take lithium batteries as an example.

  • 12V 200Ah battery can power 1kW load for 2.4 hours
  • 24V 200Ah battery can power 1kW load for 4.8 hours
  • 48V 200Ah battery can power 1kW load for 9.6 hours
  • 96V 200Ah battery can power 1kW load for 19.2 hours


You may be wondering, why is the power supply time of the 1kw solar system not detailed, but calculated from the battery voltage and current.

Know the difference between 1kw and 1kw-hr. 1kW refers to the installed capacity of a solar system (for example, 1kW solar system refers to an individual solar panel with a total rated capacity of 1kw or 1000w).

When this solar system works for 1 hour, it produces 1kW-hr of energy.

In addition, under the same 200Ah and load power, why are their power supply times different?

This is because of the difference in capacity (AH).

ls your lithium battery 100% full capacity or not?

AH is a unit for measuring electrical storage equipment capacity. Its scientific name is “ampere hour”, which means that electrical storage equipment can continue to work for 1 hour when the power supply current intensity is 1A.

WH is a form of energy (electrical energy) and is equal to the voltage of the solar battery (V) multiplied by the AH of the battery.

The resulting WH value is divided by 1000, and the result is KWH (degree).

Conversion formula: 1WH = V * AH, 1KWH = 1WH / 1000.

For example, if a battery is 48V200AH, it means that the solar battery can store a capacity of 48V * 200AH = 9.6vah / 1000 = 9.6kWh. Finally, 9.6kWh / 1kW = 9.6 hours.

Lithium battery capacity calculation

How many solar batteries do you need to power?

We need to start with two aspects:

What load (power) will you have to run after a power outage? And how long do they need to work?

Solar batteries will take up some space in your house, and the initial investment will be higher than a pure solar panel system. So when configuring solar batteries, we need to think about electrical appliances.

For example, the refrigerator must work 24 hours a day to keep your delicious food fresh. And when you sleep, are the lights, computers, water heaters, etc. necessary to keep working?

If you are a business owner and would like to use solar batteries for hotel backup power. Think about it, will every room have someone using the air conditioner at the same time?

Smart business owners can eliminate unnecessary loads based on guest room usage, reducing initial capital investment.

To facilitate comparison, PVMars lists here a table of load power that a 10kW solar system can operate, from which you can get inspiration. And think about what loads you have to run during an outage.

10000 watt solar generator Load Reference

Load NameLoad Rated PowerQTYTotal Rated Power









Computer(LCD display)




Fax machine








Washing machine




Electric cooker




Air conditioner(1HP)




Satellite TV receiver/VCD




Color TV(32 inch)




Water pump





Remark: The refrigerator, air conditioner and water pump are inductive loads, start working power is 3-6 times more than normal power, in the process of use, turn on the inductive load first

According to the table above, during a hypothetical power outage, a 1 x 9000 BTU air conditioner must be run for 12 hours. In addition, 1 x 300W refrigerator for 24 hours, 1 x 2000W washing machine for 1 hour, and 10 x 30W lights for 8 hours.

The calculation method is as follows:

9000 BTU = 1HP = 750W, 750W * 12 hours = 9000Wh.

300w * 24 hours = 7200wh, 2000w * 1 hour = 2000wh, 10 * 30w * 8 hours = 2400wh.

9000wh + 7200wh + 2000wh + 2400wh = 20,600wh = 20,600vah / 96v = 214.6ah.

96V is the DC voltage of the 10kW inverter. Please note that the DC voltage of the battery needs to be consistent with the DC voltage of the solar inverter.

Finally, you will need a 96V 200AH or 250AH lithium battery for backup power.

PVMars’ 96v 200ah lithium battery EXW costs US$3,291. For more specifications of lithium batteries and prices for other models, please contact [email protected].

From here it can be concluded that how many batteries and electrical load power you need are inseparable from the running time.

If the load power becomes 10kW or the operation time is longer, the number and capacity of batteries required will also change.

In addition, there are many types of solar batteries, and the capacity matching between them also varies.

What factors affect solar battery energy?

Solar batteries store energy related to the type of battery, ambient temperature, and solar panel output power.

Solar battery type:

In the past few decades, lead-acid batteries were once the most popular battery type due to their price and mature technology.

However, to increase their service life, their usage capacity needs to be limited. For example, for a 10kWh lead-acid gel battery, the solar inverter needs to be controlled to stop working when the output reaches 8kWh or 7kWh to ensure the cycle life and safety of the battery.

Due to the low number of deep cycles (DOD) of lead-acid gel batteries, more and more people are leaning towards lithium batteries.

PVMars’ lithium batteries use the world’s safest and longest-lasting lithium iron phosphate as the raw material for lithium batteries.

We produce and provide lithium batteries with a DOD of up to 98%, allowing your solar system to power for longer.

According to laboratory data, at a temperature of 25°C, 1C discharge, and 0.5C charge, the cycle life of the lithium battery pack can exceed 4,000 times. The service life is about 10-12 years.

For example, our Saipan customers prioritize lithium batteries as their hotel energy storage power source. You can click on the orange font to get more information about the case.

In addition to the current mainstream lithium batteries, there are also flow batteries suitable for medium-sized systems (above 1MW).

However, due to the relatively large size of flow batteries and the cost being higher than lithium batteries, more large-scale energy storage projects still prefer lithium batteries.

Are all regions suitable for lithium batteries? This is not necessarily the case. We also need to consider environmental issues.

Ambient temperature:

Lithium batteries are recommended to work between -10℃ to 55℃. So it is not suitable for use in -20°C environments.

These environments are usually suitable for the application of lead-acid gel batteries.

For example, PVMars’s solar installation team spent about 10 days successfully installing a 200kW solar energy storage system.

This was in an area with an altitude of 4,000 meters. It was equipped with a 2V gel battery. You can see from the video that neat rows of gel batteries lie quietly in the room:

Output power of solar panels:

Solar panels are the main source of energy to charge solar batteries.

For example, how many solar panels does it take to fully charge a 96V 200AH lithium battery?

96v * 200AH = 19200wh / 4 hours (average sunshine duration) = 4800w / 580w = 8.3.

It takes about 9 x 580w solar panels to fill a 96v 200AH lithium battery.

If you only have 4 solar panels, don’t be frustrated, the remaining energy can be replenished in other ways.

PVMars’ lithium batteries can be charged from traditional utility grids, wind turbines, diesel generators, and solar panels.


Solar batteries can operate for 24 hours during a power outage without AC or DC electrical loads running. But is this possible?

Solar batteries are used to provide emergency power, store electrical energy, or be the main power supply equipment at night and on rainy days. It will always need to stand by.

So PVMars Solar Energy Storage Company strongly recommends that you configure solar batteries based on your actual situation when purchasing batteries.

This can effectively avoid after-sales risks and initial investment proportions.

Kevin, who has a dual master’s degree in mechanical engineering and chemistry, is the manager of PVMARS wind energy storage’s R&D department. He is passionate about solving users’ problems and overcoming technical barriers

Share to

PVMARS Solar will set up 120 energy user service centers around the world. It will provide on-site investigation, design drawings, solar energy storage system solutions, transportation of goods, assist you to import solar energy storage system, installation services, and continue to cooperate with local engineers, exclusive agents and foreign merchants.

We sincerely hope to work with like-minded partners. Win-win cooperation to achieve harmonious coexistence between mankind and nature.

Our products

latest QA center

Contact us

Write to us

we will get back to you as soon as possible

Please enable JavaScript in your browser to complete this form.
10 pm or Saturday 2 pm or when?
Do you have existing solar power system?
Installation place
Which product are you interested in? Multiple options available
March or June or December this year or next year