The installation of renewable energy sources is pretty common nowadays. Almost every commercial or residential facility includes a solar system. Most are wondering what battery type and size they need.
LiFePO4 batteries are the ideal choice for high capacity and long-term performance. But most people make mistakes by either oversizing or undersizing LiFePO4 batteries. Today, we will discuss the significance of LiFePO4 batteries and how you can choose the right size at an affordable cost.
Why Does the Right LifePO4 Battery for Solar Energy Storage Matter?
Choosing the right-sized battery storage is pretty critical. Before we understand the right size, we must know how the wrong size affects us.
Undersized LifePO4 Battery for Solar Energy Storage
The battery serves as storage. If you need 5 kW while you have a 4kW battery, it won’t last long.
An undersized battery has several disadvantages.
- Fails to system properly.
- Discharges quickly.
- Experiences an early setback due to a smaller size than required
Oversized LifePO4 Battery for Solar Energy Storage
Oversized batteries look beneficial, but they are more than that. If you buy an 8kW system for a 5kW system, it is overkill and has a few disadvantages.
- It is often expensive.
- Wastes money and energy stored.
Right-Size LifePO4 Battery for Solar Energy Storage
If you are looking for the right size LiFePO4 battery, it is a great choice for the following reasons.
- Your system runs efficiently and delivers the power.
- There is an early discharge.
- You can save more money than with the oversized system and ensure the future expansion goals.
Step 1: Calculate Your Daily Electricity Consumption
When choosing the right LiFePO4 battery for solar energy storage, the first step is to determine your energy consumption.
How much energy do you consume? The calculation is simple.
Power of the appliances x running hours
Suppose we use an example of different devices; then let’s apply this formula and calculate the overall power consumption.
| Eletrodoméstico | Poder | Daily Usage | Daily Energy |
| LED Lights | 120 W | 6 Hours | 720 Wh |
| Frigorífico | 180 W | 10 Hours | 1,800 Wh |
| Televisão | 120 W | 4 Hours | 480 Wh |
| Ceiling Fans | 150 W | 8 Hours | 1,200 Wh |
| Computador portátil | 80 W | 5 Hours | 400 Wh |
| Wi-Fi Router | 15 W | 24 Hours | 360 Wh |
As per the calculation, the total energy consumption is 4,960 Wh per day. It means that if you buy a LiFePO4 battery system with a 5kW capacity, it will be sufficient to power all the listed devices.
Passo 2: How Much Backup Power Do You Need?
It is not just about daily use, but about the backup power you need. You must calculate the backup needed.
- Normal backup is up to 1 day.
- Frequent outages require a battery backup of up to 2 days.
- Remote cabins should have a backup for 3 days.
- Off-grid homes plan for a backup of 3-5 days.
Suppose your daily consumption is 5kW. For a one-day backup, you must have a battery storage capacity of 5kW. For the two days, it will be 10kW.
You can multiply the number of days by the battery storage power.
Step 3: Consider Battery Depth of Discharge (DoD)
Depth of discharge matters as batteries don’t allow the full discharge. Guess what? AGM and lead-acid batteries allow 50% discharge.
Compared to it, a LiFePO4 battery allows 80-90% discharge of its capacity.
Let’s understand it by an example.
Suppose you have installed a 10kW battery system. If you discharge Lead-Acid Batteries, you get 5kW after the 50% discharge limit. For LiFePO4 batteries, you can get up to 9kW after 90% of discharge safely.
It means LiFePO4 batteries better support your system and provide greater safety by consuming much of the stored backup supply.
Step 4: Match Battery Size With Solar Panel Output
This is where most buyers are going to make a mistake!!
Buying high-capacity batteries doesn’t mean you save more energy. A compatible size and targets are better. You should match the battery sizes with your solar panel outputs.
For example, you have installed a series of 10 solar panels, each having a power production of 600 watts. It means the total power production from the solar array will be 6kW.
Suppose sunlight is at its peak for 5 hours a day and your solar panels offer a 97-98% production efficiency.
The total power production will be:
Power output= 5 x 6kW =30kW
Now, you should subtract the average power usage. Suppose it is 11kW. So, the excess energy produced is 19kW. You should install batteries with a capacity of 10-19 kW. Buying a larger size doesn’t charge the batteries fully and causes oversizing issues.
Step 5: Consider Weather
Since you installed the solar panels as your energy source, they are affected by environmental conditions. If there is no sunlight on a cloudy day, you won’t produce much energy and need large batteries for:
- Frequent cloudy days
- Heavy rainfall
- Long winters
- Seasonal snow
- Frequent storms
Depending on local weather conditions, you should buy the larger batteries if you frequently experience cloudy days.
In regions with frequent outages or cloudy weather, they should maintain a safety margin of 15-30% above the required capacity.
Step 6: Identify Critical Loads
Do you reduce battery costs by buying a smaller setup than required? You want to invest in 5kW batteries instead of a 10 kW battery.
Technically, it looks challenging, but it is possible by cutting unnecessary devices and loads from the overall power consumption.
You should identify only the necessary appliances and run them during the power outages. The household features the following necessary devices:
- Frigorífico
- LED lighting
- Internet router
- Security system
- Equipamentos médicos
- Water pump
- Mobile phone chargers
- Small kitchen appliances
You should calculate their loads and buy a battery size suited to power these appliances.
Recommended LiFePO4 Battery Sizes for Different Applications
Different applications require a different LiFePO4 battery size. Here is an overview of the few applications with their battery sizes.
Small Cabin or Tiny Home
A small cabin or a tiny home doesn’t have many appliances. They have only a few devices, such as:
- Iluminação
- Computador portátil
- Mini refrigerator
- Phone charging
- Internet
They have lower energy consumption, of up to 3kW. Since these tools are essential and critical ones, you should buy a battery size of 3-5kW to power these critical loads during the power outage.
Small residential home
Small residential homes have the basic appliances. They often operate the following devices.
- Frigorífico
- Televisão
- Fãs
- Iluminação
- Internet
- Small kitchen appliances
Depending on the power consumption, they often use 5-8kW of power daily. The recommended power consumption is 8–12 kWh.
Medium-sized home
Medium-sized homes have slightly higher power consumption than smaller houses. They often operate the following appliances.
- Air conditioner
- Electric cooking
- Washing machine
- Water pump
The average consumption is around 10–15 kWh, while you should buy a battery system of 15-20kWh.
Large Family Homes
Large family homes have multiple appliances. Instead of one air conditioner, they have many. Therefore, the power consumption peaks in such families. The common examples of appliances are:
- Multiple air conditioners
- Electric cooking
- Washing machines
- Sistemas de entretenimento
- bombas de água
- Larger household loads
The daily consumption is 20–30 kWh, while recommendations are for 25–40 kWh of battery backup.
Off-grid Solar Systems
Off-grid solar systems have independent energy production and utilization. There is no connection with the grid systems. Since you don’t have any other source of power for your system, a large battery storage system is recommended. For example, the daily demands are 15–25 kWh while the recommended battery should be 30-60kW to keep your critical loads running for several days.
Perguntas frequentes
- Can a LiFePO4 battery power my entire house during a power outage?
Yes. Your LiFePO4 battery can power your house during the outage. However, based on your power demands and operating expectations, choose the right-sized LiFePO4 battery for solar energy storage.
- Is a LiFePO4 battery better than a lead-acid battery for solar storage?
Yes. LiFePO4 batteries are far better than Lead-Acid batteries due to longer lifespans, better compatibility, and easier future expansion. The durability makes them more suitable.
- Can I expand my LiFePO4 battery capacity in the future?
Yes. Most LiFePO4 batteries come with modular systems that make expansion easier. It keeps the system flexible and scalable.
- How long does a LiFePO4 battery last in a solar energy storage system?
LiFePO4 batteries have a long lifespan of 10-15 years. If you want high performance, maintain your batteries regularly and get long-term durability.
- What size LiFePO4 battery for solar energy storage do I need?
LiFePO4 battery sizes vary. You should choose the LiFePO4 battery sizes based on your power needs, storage conditions, and how long you want to run them on a single charge.
Conclusão
Choosing the LiFePO4 batteries is a wise decision. However, you should know your requirements, calculate the appropriate size, and buy a compatible energy storage setup. LiFePO4 Battery for Solar Energy Storage is a perfect solution if you choose a top brand and opt for warranties.
Luxpowertek has introduced the PGEM Battery Storage Series, offering high capacity, reliability, and outstanding performance in all conditions. With a 6000-cycle lifespan, you will get more than you need. Choose our top-notch battery solutions right away!