Having a solar panel battery bank means you won’t need to use electricity from the grid. This can bring you significant savings as you will no longer need to pay for utility-supplied power. These savings are on top of potential tax credits in the US for installing solar panels on your roof.  

 

What is a Solar Panel Battery Bank?

Many solar systems are connected to the electricity grid. This allows independent electricity producers to feed excess energy into the grid. It also lets you use electricity from the grid during times when your solar panel system may not be producing as much power as you need. This could happen for a number of reasons. For example, your solar system may not be producing as much energy as it could on cloudy or rainy days. I will also not be producing power during the night.

You may be able to benefit from net metering (depending on your location) if you feed electricity into the grid. On the other hand, you could end up having to pay for utility electricity that you use while your solar system is not providing you with enough power.

Adding a solar panel battery bank to your solar system could avoid additional electricity payments since you will be able to use the stored power that was generated by your solar power system. Excess electricity produced by your solar panel system gets stored in the solar panel battery bank. This is then used during times when your solar panel does not produce sufficient power for your needs.

 

How do solar battery banks work?

When your solar system absorbs sunlight, it converts the sun’s energy into electricity via an inverter. This solar power electricity can then be used to power your home. Any excess power is then fed into your solar power battery storage system. The rate at which your solar power battery bank gets charged will depend on the amount of excess energy your system generates.

Your home runs on alternating current (AC), while solar batteries are charged by direct current (DC). A solar inverter converts AC into DC to charge your solar battery bank and back to AC for use in your home.

 

Different kinds of solar batteries.

There are various options to consider when looking for a solar power battery. Different types of batteries are designed for different uses. More than that, solar batteries differ in how they store power, and this influences their lifespan and cost.

Suppose you are connected to the grid with the option of using utility-supplied power. In that case, a standby solar power bank could work for you. These systems can provide you with energy in the event of a power failure. Entirely off-grid solar systems will require a more extensive solar power bank to support your household’s energy needs at times when your solar power system cannot generate enough electricity.

Standby solar batteries.

A standby solar power battery is an emergency backup that will kick in in the event of a power failure. These batteries are used to run essential electronic systems in your home like your UPS and security system. Standby batteries are only used sometimes and rarely discharge completely. When looking for a standby solar battery, you will look at its standby life. Because these batteries are unlikely to be discharged regularly, you need to consider how long they will last in a fully-charged (or nearly fully charged) state long-term. That is what is referred to as the battery’s standby life.

Deep cycle solar batteries.

A deep cycle solar battery can be used as an everyday power source to supply power to your home when your solar panel system is unable to do so. When these batteries are used to power your home when your solar system cannot, they get deeply discharged. Every time this power source is charged and discharged is referred to as one cycle. When looking for a deep cycle solar power battery, you need to consider its cycle life. This represents the number of times the battery can be charged and discharged before it reaches the end of its lifespan.

Deep cycle batteries are ideal for use with your solar panel system. The batteries are charged by solar power generated by your solar system during sunny days. This stored power can then be used to supply electricity to your home while your solar system cannot.

There are two main types of deep cycle batteries: lead acid and lithium. Lead acid solar batteries are 99% recyclable. These batteries are incredibly affordable and designed to be cycled on a daily basis. The drawback of a lead acid battery bank is that you cannot add new batteries into the array after the batteries have been cycled a number of times.

Flooded lead acid batteries can be charged and discharged regularly. These flooded batteries release hydrogen gas that needs to be adequately ventilated. You will also need to perform regular maintenance on these batteries, like checking the water levels and equalizing the batteries at least every 90 days.

Sealed AGM lead acid batteries are best used as an emergency backup power storage system. AGM batteries require less maintenance and do not off-gas. However, sealed batteries are more expensive than flooded lead-acid batteries.

Lithium batteries can be discharged deeper than lead-acid batteries. These batteries can be discharged to nearly 100%, where a lead acid battery should be discharged to around 50% at most. Lithium batteries also charge faster and can be used even when it is not fully charged without significantly affecting the lifespan of the battery. Lithium batteries typically last for around 10 years or have a 10,000 cycle lifespan. Lithium batteries require less maintenance and don’t off-gas.

While lithium batteries cost 3 to 4 times more than lead-acid batteries, you can add additional batteries at any time. That means you can start off with a smaller battery array and increase it over time.

There are two types of lithium batteries; lithium ion and lithium iron. Both can be used as part of your solar power storage system. Still, the type of lithium battery that will be best for you will depend on how and where you will be using it. Your solar power system installer would be able to advise you on whether you need to consider a lithium iron or lithium ion battery.

The lifecycle of your solar energy storage system depends on a number of factors. This includes how often the battery pack is charged and discharged, where and how you store the solar battery storage system, and how well you maintain it.

 

What size solar battery do you need for your home?

The size of your solar panel battery bank will depend on how much energy you need while your solar system is not producing power. This is referred to as energy usage and measured in kilowatt hours over a period of time.

For example, you may use 1,000 watts of electricity for 10 hours a day. That means you need 10kWh per day to meet the power requirements in your home. You will likely want to store a few days’ worth of power in your solar panel battery bank. Depending on your location, local weather patterns, and energy requirements, you may need to store between two and five days’ worth of energy.

There are different ways to calculate the required size of a solar panel battery bank. It is best to speak to your solar installer, who can advise you on what would work best for your needs.

One way to calculate the battery capacity you need is to multiply your daily kWh electricity usage by the amount of days’ worth of power you wish to store. This amount should equal to a 50% depth of discharge on your batteries. Thus, if you use 10kWh per day and want a 3-day supply of backup power, you will need 10 (kWh) X 3 (days) X 2 (depth of discharge at 50%) = 60kWh.

You can then convert the kWh to amp hours (AH) by dividing the required kWhs by the voltage of the battery you will be using. Most batteries are either 12, 24, or 48 Volts. If you choose to use 48 Volt batteries, the calculation will look like this:

60,000 watt / 48 = 1250 AH (or 1250000 MAH).

To calculate how many batteries you need, divide your required AH by your battery’s AH rating. It is always a good idea to round up to account for potential losses of power. That means

 

Other equipment that you need to install along with your solar energy battery bank.

The batteries make up only part of your solar energy storage system. When installing a solar power bank, you need to include a solar charge controller. The charge controller regulates the amount of voltage or current that flows through your solar energy batteries. This keeps them from over charging.

Most 12 volt solar panels put out between 16 and 20 volts, while most batteries require between 14 and 14.5 volts to charge fully. Your charge controller ensures that your battery does not receive too many volts, which could damage the battery and shorten its lifespan.

Solar energy storage systems allow you to store power generated by your solar power system for use during times when the system cannot generate electricity. While this means you need to invest more money into your solar system, it could bring you significantly more savings on your utility bill and move your home entirely off-grid.

It may be tempting to install your solar system yourself. Keep in mind that self-installation and maintenance could cost you in the long run. If you do go this route, speak to your local solar shop and installer to give you the best advice on how to go about it.