Having a solar system can definitely minimize energy consumption on the grid. But when the sun goes down, using a battery bank is the solution to continue using solar after-hours.

A solar battery bank is an energy storage solution that creates a way to use solar panels when the sun is not available. The battery bank connects more than one battery to allow for more storage capacity or higher voltage depending on your needs.

A created battery banks helps with a true self-sustaining cycle of electricity use. You don't have to worry about going "back to the grid" when darkness hits just because the sun went away.

Thinking about wiring batteries can be intimidating, but it doesn't have to be! Taking the right precautions and truly understanding how batteries work for solar will help reap the benefits of your solar production.

How Does a Solar Battery Bank Work?

The idea behind a "bank" of batteries is to collectively join more batteries together in order to increase one of two things: voltage or amps.

To throw some battery terminology in the mix, let's talk about series and parallel connections.

Series Battery Wiring: Connection and Diagram

two batteries wired in series connection
12V 100Ah batteries wired in series diagram

Wiring batteries in series will increase the voltage. This obviously depends on the number of batteries used, but the principal remains.

As an example, with two 12V batteries with an amp-hour rating of 100, connecting two batteries together results in a 24V battery.

When batteries are connected, they don't really have a smart memory. In any order they are connected, the source and ground connections remain like a single battery.

Parallel Battery Wiring: Connection and Diagram

two batteries wired in parallel connection
12V 100Ah batteries wired in parallel diagram

Wiring batteries in parallel will create more capacity. No matter how many batteries are used, the capacity adds together.

For an example on a parallel battery connection, the same 12V batteries with an amp-hour rating of 100 wired in parallel will result in 200Ah  (100Ah+100Ah) capacity.

Refer to the battery bank tutorial on batterystuff.com website for more information on these types of connections.

FAQs

How does a solar battery bank work?

How is solar energy stored in batteries? Solar batteries work by storing energy produced by your solar panels for later use. In some cases, solar batteries have their own inverter and offer integrated energy conversion. The higher your battery's capacity, the more solar energy it can store.

How is Solar Energy Stored? | EnergySage
Learn how solar batteries store energy for later use. Get the breakdown on solar plus storage.

What is a battery bank for solar energy?

The battery bank means several batteries with parallel and series connection set up into an energy storage bank, which store solar energy from solar panel and provide electricity to loads via DC-AC inverter. Battery bank is core item in a solar power system as an energy storage.

How to build battery bank for solar power system by using deep cycle batteries - LWI
As solar battery is always being fully charged and deeply discharged, we should choose deep cycle battery for battery bank of solar power system.


How long will a solar battery bank last?

The general range for a solar battery's useful lifespan is between 5 and 15 years.

What is the Best Battery for Solar Storage? | EnergySage
Need help choosing a solar energy battery? This guide will help you find the best solar storage option for your solar panel system.


Are solar powered power banks any good?

In short, solar power banks and portable solar chargers offer convenience for the consumer. While they are energy-efficient, they may not always be a money-saving option. So, their worth will largely depend on their application and consumer preference.
Source: https://solarpowergenie.com/are-solar-power-banks-worth-it/

Is it worth getting a solar battery?

The value of a solar battery depends on preference. If living with an off-grid type of setup, it will definitely be worth the cost and time to setup the battery so energy can be used without the sun.

If you are just trying to offset the cost of grid electricity with solar panels, it's possible having a solar battery will be more work than benefit.

References for more information

Understanding Battery Configurations | Battery Stuff
Find out more about battery configurations, such as series, parallel, and series/parallel. Learn how to connect two or more batteries properly.
How to Size Your Off-Grid Solar Batteries
How to Size Your Off-Grid Solar Batteries: If you are designing a solar electricity system and don’t have access to the grid, you are going to have to deal with batteries. When you start looking at solar batteries you are going to encounter a little math. Fortunately, SolarTown is here to g…