How to Choose the Best Battery Backup for Your Home/Family Needs

Solar battery banks are always a safe bet. For one, you will be able to have power during rolling blackouts. Additionally, you can power your home using battery power during the day when utility power is most expensive. If you plan to purchase a solar battery bank, here is how to pick the right one.

Decide How Many Batteries You Need

The most important factor is deciding how many batteries you need in the home. The answer will depend on what you wish to power with the batteries.

If you want to power the entire home, you will need a “whole home system,” which can power the AC, refrigerator, washing machine, and lights in your home. If you want to preserve frozen foods and keep the lights on, you can opt for a “critical loads” only system. It will not power AC, but it will keep Wi-Fi, power outlets, and lights running.

Calculate Your Need

If you plan to power the whole home, you need to estimate your daily-average use. You can use your electricity bill to determine how much power you use. It will show you how many kilowatt-hours you use in a month. Ensure that you pick the month with the highest usage when making your calculations. In California, the average peak months are July and December when the average power use is 675 kWh per home, making it 22kWh per day.

When buying the solar battery bank, ensure that it can store at least 22 kWh. Besides that, you need to calculate how much power your solar system can generate in a day.

For those who only wish to power critical loads, you can opt for a small capacity battery bank that is wired to only power essential appliances. This will mean getting a battery bank that stores at least 13 kWh.

Length of Usage

In addition to the amount of power you need, you should consider what happens when the panels are not producing power for days due to the weather. If it is cloudy, solar panels do not generate power. As a result, you should consider a battery bank that can hold power for up to three days of use. As a result, if your daily usage is 22 kWh, you need a batter bank that can store up to 66 kWh or more.

Types of Batteries to Mate with Solar Power

Three main types of batteries can be mated to a solar system. They are:

Absorbent Glass Mat (AGM) Deep-Cycle Batteries

Flooded Lead Acid (FLA) Deep-Cycle Batteries

Lithium-Ion Batteries

To determine how many of each type you need, you need to understand how each type works. Each battery is rated to produce a set number of amp hours at a set voltage.

For the FLA, you can get 12V at 200 AH. V x AH=Wh. To get the KWh, simply divide the Wh by 1000.

The result is that 12V at 200 Ah means you can store 2.4 kWh in one battery. To store 66 kWh, you would need around 28 car batteries stored securely.

Another consideration is the depth of discharge (DoD). For FLA batteries, the DoD is 50% of its capacity. That means that with 2.5 kWh , only 1.2 kWh will be available for use, bringing the number of total batteries needed up to 56 for three days of power.

AGM batteries, with a DoD of 80%, provide a more efficient alternative to FLA batteries.

Lithium-Ion Batteries

These batteries are used to power electric vehicles and your cell phone. They are light, compact, and have a long lifespan of up to 10 years. Besides that, they have a DoD of 100%, making them the most efficient battery of the three.

Summary

If you plan to get a home battery bank, the above-mentioned points should help to give you a basic guide.