Can a Solar Battery Be Charged With Electricity?

Many households are beginning to add solar batteries to their solar power system. These batteries provide a reliable power source by storing excess electricity so your home appliances can run even when your solar panels aren’t generating enough electricity. This reason, as well as helping to cut energy costs and reduce the impact on the environment, makes adding solar batteries to your solar set-up worth it.

To keep your solar batteries working, they need to be recharged with sunlight now and then. But what happens when the skies are cloudy or rainy? Or when it is nighttime, and you desperately need to charge the batteries?

The other alternative might be to use electricity to charge the solar batteries. In this piece, we’ll be exploring the possibility of this alternative. Keep reading to find out more!

Can You Charge a Solar Battery With Electricity?

Once you’ve considered connecting rechargeable solar batteries to your solar system, you can begin to use the electricity generated from your solar energy even when there’s no sun. But sometimes, your solar panels might not generate enough power to charge your batteries.

In such cases, you can charge the batteries with electricity from your local power grid. But it is not a suitable option because of power losses and should only be considered in times of emergencies. There are, however, a few things you should bear in mind before charging your batteries with electricity.

Firstly, you should consider that your solar batteries would take some time to charge, so you should be careful of what time you decide to charge them from your local grid. Also, it would help if you considered that since you are charging from the local grid and aren’t using it to run any other equipment, charging another battery will cost more.

Also, when the battery is connected to your local grid, you should fix the charge time because you’re not using the energy from the solar panels. Also, the power grid uses AC and not DC power.

So, you might need to convert the AC to DC with a solar inverter charger when charging your batteries. Although this system is not 100% efficient, it may cause the batteries to lose some energy while charging. 

Is It Good to Charge the Solar Battery With Electricity?

Solar batteries are essentially manufactured to help us shift towards more sustainable energy by storing power from a renewable energy source. The primary fact is that you’re expected to charge the batteries first with solar energy always. So, having to charge them with electricity defeats the purpose of installing them in the first place.

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The energy produced from your local grid is derived from non-renewable sources such as fossil fuels and nuclear plants. But solar energy provides you with the same amount of energy every day. This means you don’t have to store up power for long.

Charging your batteries with electricity increases the amount of electricity you consume, increasing your electricity bill even if your area has low electricity charges.

Also, the batteries deplete at a fast rate while charging and could result in energy loss, making it an ineffective method. Also, electricity produces a high current which might reduce its life span or cause permanent damage to your battery.

If you don’t have enough solar supply, charge your batteries with the bit of solar energy available and then top up the charge with power from the grid. And be sure to stay away from the battery when charging as it tends to explode under certain conditions.

When Should You Charge the Solar Battery with a Power Grid?

Grid power is much more expensive than solar power, so you must keep electricity costs as low as possible. So, if you must charge your solar batteries with a power grid, it’s best to charge them when the tariff charge is significantly lower to save costs.

In some areas, the tariff costs are lower at night because electricity consumption is lower. Also, the PV might not be able to supply enough energy during the day; on such days, you might not be able to connect the solar batteries to the grid and charge fully.

Do You Need an Inverter to Charge a Battery?

A regular inverter’s job is to convert DC power to AC, and it does not charge batteries. Instead, it draws the DC power from the batteries to run your AC appliances and cannot work in reverse. However, a solar inverter charger is a different case entirely.

A solar inverter charger works like a regular inverter but also has a transfer relay and an in-built battery charging unit. This type of inverter efficiently charges batteries from any power source, solar or grid. It also converts AC power from the grid to DC power to charge the batteries. It also uses the AC power from the grid to keep the batteries full in case the grid goes down.

By doing this, the solar inverter helps to reduce the strain on your local grid.

Can You Charge Solar Batteries With a Generator?

A generator can help when you have no electricity or another energy source to charge your solar batteries. As long as your generator is connected to your battery correctly, charging is possible and automatic. You must also know your battery’s specifications to regulate the charging.

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Although a generator provides the necessary voltage for charging solar batteries, you would still need an excellent inverter to convert AC power from the generator to the DC power required to charge the batteries. Therefore, you cannot connect the battery directly. The generator should also be twice the size of the inverter.

Ideally, a generator should take about 5 to 8 hours to charge an empty battery fully. But often, the time required for a full charge depends on several variables, such as the voltage reaching the battery, the battery’s size, and the battery’s condition.

Hence, the battery will take a little longer to charge fully if a charge controller is used. This is because it only allows about twenty percent of voltage to reach the battery while charging.

Can you Charge Batteries From the Charger and Solar at Once?

Most batteries come with a dual charging feature and are always highly efficient so that you can charge with both grid power and solar energy. The energy supply is most important when trying to charge your batteries. You only have to ensure that the right amount of voltage is passing through the cable such that your batteries can charge in safe mode.

Solar batteries discharge at a slower rate, so they store the energy for future use when you charge them. However, the battery chargers regulate the flow of electrons from a higher to lower voltage. When the voltage is higher than the EMF, the electrons flow to and from the anode to the cathode. This means that you have to use the appropriate battery chargers.

As a result, their discharge rate can be optimized and used in the lower voltage level. If you get confused about which equipment to use, contact the battery manufacturers to get accurate information on how to use it.

Can you Charge a Solar Battery With a Car Battery Charger?

Strange as this might sound, yes, you can charge a solar battery with a car battery charger; so far, you first make sure that the charger is suitable for your solar battery.

To do this, check the specification of your battery to see what type of chargers are compatible with it. Or read the specification of the car charger to decipher what type of batteries it supports.

Luckily, most solar companies sell all solar equipment together, so all their equipment is compatible. However, the battery’s charging process boils down to the battery chemistry. Lead-acid batteries align with the car chargers and produce enough energy to charge the batteries. They are also easily compatible.

Automatic car chargers will help charge the battery and cut off the power supply when the battery is full.

How Do you Know a Solar Battery is Fully Charged?

There are several ways to check the charge level of your solar battery. You can use charge controllers or inverters if you have them as part of your solar power system. But if you don’t have them, you could use meters such as voltmeters or multimeters that aren’t fixed in the system.

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Solar batteries take about five to seven hours to reach full charge under suitable weather conditions. And longer under poor conditions. You can use a charge controller to check the charge of the battery. A proper charge controller has a display screen that will indicate the amount of voltage going into the battery. It will indicate when the battery has reached its float level.

Charge controllers without a screen usually have a light that displays when the battery has reached the float phase and is complete. Inverters also have a display screen showing the battery’s charge level. But other inverters have a noise or light feature that signals you when the battery is charged or running low.

Voltmeters come in analog or with a digital display. Either way, they always provide accurate results. To use a voltmeter to determine the battery’s charge, you should connect the voltmeter to the black and red ports on a battery that is rested. A reading of about 13 volts means the battery is fully charged.

Multi-meters also work the same way voltmeters do. It also comes in both digital and analog. When using an analog multimeter, you should check the voltage indicator. At the same time, a digital one will require you to select the voltage setting. However, a digital multimeter is more accurate than an analog.    

Where Does Solar Power Go When Batteries Are Full?

When solar batteries are full, the excess energy, whether solar or electric, goes to waste if not directed elsewhere, which is the charge controller’s job.

The charge controller is set up to divert excess energy depending on your solar solution. The two types of solar solutions are off-grid and grid-tied solar set-ups. In a grid-tied solar format, the charge controller charges the batteries until they’re full. Then it sends the excess energy to the inverter from the battery.

The inverter then converts the DC power it receives into AC power that powers the home appliances. Any energy that isn’t consumed by the batteries or the appliances is then sent back to the grid using the electricity meter. Some electricity companies even credit you when you send power back to the grid. 

On the other hand, the off-grid set-up features a generator that continuously supplies power when the batteries and solar panels aren’t. So, any excess energy will be wasted unless directed to other systems such as refrigeration or water-heating systems. Some off-grid users also have automatic systems that turn on some appliances with excess power.


Apart from solar energy, it’s essential to have an alternative energy source because solar power can be unstable. Installing a battery can help tackle the uncertainties of using solar power and provide adequate backup.

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About Rinkesh

A true environmentalist by heart ❤️. Founded Conserve Energy Future with the sole motto of providing helpful information related to our rapidly depleting environment. Unless you strongly believe in Elon Musk‘s idea of making Mars as another habitable planet, do remember that there really is no 'Planet B' in this whole universe.