Like other battery types, lithium batteries are made up of several cells. However, the standard voltage of lead-acid batteries is 2V/cell, while lithium battery cells have a standard voltage of 3.2V. As a result, a 12V battery is usually made up of 4 cells connected in series. 

Because their charging voltages are so similar, lithium batteries are frequently used in place of lead-acid batteries. Lithium batteries are unique in that they do not require an absorption charge or to be kept at a constant voltage for long periods. When the battery achieves its maximum charge voltage,  you no longer need to charge it. Lithium batteries sustain a far higher voltage during discharge than lead-acid batteries while loaded. 

The solar business was rocked when lithium-ion solar batteries were introduced since the solution provides several advantages over lead-acid batteries. Still, there are a few drawbacks.

Pros of Lithium Ion Solar Batteries 

Some of the positive aspects of lithium-ion solar batteries include:

Higher Depth of Discharge (DoD)

A battery's DoD is the percentage of the battery's stored energy that has been consumed relative to the overall capacity. To keep the battery healthy, most lithium batteries come with a recommended depth of discharge.

Lithium-ion solar batteries are deep cycle batteries with DoDs of about 95%. The DoD of most lead-acid batteries is only 50%. This means you can get more out of a lithium-ion battery's stored energy without needing to recharge it as frequently.

Greater Efficiency 

Lithium-ion batteries have a greater round-trip efficiency than other kinds of solar batteries. Efficiency is essentially the quantity of useful energy you get from your battery versus the amount of energy needed for storage. Lithium-ion batteries have efficiencies ranging from 90% to 95%.

Less Maintenance

One of those lithium benefits that you can't set a figure on is not constantly worrying about routine maintenance. Unlike flooded lead-acid batteries, lithium-ion solar batteries don't require maintenance.

Unlike flooded lead-acid batteries, which must have their water levels monitored, lithium-ion batteries don't need to be watered. This reduces the amount of maintenance required to keep the batteries working, as well as the requirement to train new employees on the maintenance procedure. 

Longer Lifespan

Lithium-ion batteries last long since they have a greater DoD and don't have to be charged and recharged as frequently.

Many lithium-ion solar batteries last up to 10 years or 10,000 cycles. The lifespan of lead-acid batteries, however, is only about 5 years.

Higher Energy Density

A battery's energy density refers to how much energy it can store in relation to its physical size. Lithium-ion batteries can hold more power while taking up less space than lead-acid batteries. This is ideal for households with limited space.

Self Discharge

The self-discharge rate of many rechargeable batteries is often a problem. The self-discharge rate of lithium-ion cells is substantially lower than that of other rechargeable cells such as Ni-Cad and NiMH. It is generally around 5% for the first four hours after charging but drops to about 1% or 2% per month thereafter.

No need for Priming

Some rechargeable batteries need to be primed before they may be used for the first time. One of the advantages of lithium-ion batteries is that they are delivered fully functional and ready to use.

Variety of Types

Lithium-ion cells come in a variety of shapes and sizes. This benefit of lithium-ion batteries means that the appropriate technology can be used for the purpose at hand. Some lithium-ion batteries have a high current density, making them excellent for consumer electrical devices. Others may deliver even larger currents, making them perfect for power equipment and electric vehicles.

Cons of Lithium-Ion Solar Batteries

Lithium-ion batteries' disadvantages include:

High Cost

When contrasted with lead-acid batteries, lithium batteries are the most pricey battery alternative.

The great news is that solar batteries are eligible for rebates such as the federal tax credit, which help to lower their cost. Furthermore, while lead-acid batteries are less expensive, they must be replaced more frequently than more durable lithium-ion batteries.

Battery Management System Required

Lithium-ion batteries and cells must be safeguarded against being overcharged and discharged too far. Furthermore, the current must be kept below safe limits. As a result, one downside of lithium-ion batteries is that they require protection circuitry to guarantee that they remain within their acceptable operating limits.

Fortunately, modern integrated circuit technology allows this to be easily implemented into the battery or, if the battery is not interchangeable, into the equipment.The battery management circuitry is integrated, allowing li-ion batteries to be used without any special knowledge. They can be left on charge until the battery is fully charged, at which point the charger will cut the power supply off.

Since they take up minimal space while holding a significant amount of electrical power, lithium-ion solar batteries are the optimal solar power storage solution for regular household use. Their high DoD also means you can extract more of the energy you've stored.

Because the battery will survive longer than a lead-acid battery, it will not need to be replaced as frequently. Plus, as they are more efficient, you can utilize more of the power your solar panels generate and store, getting more value for your money.

Lead-acid batteries are commonly utilized in solar system installations not used on a daily basis, such as vacation cabins. However, for regular usage, a lithium-ion solar battery is definitely the optimal option.

Introducing the Lithium-Ion Phosphate Battery

Lithium iron phosphate (LiFePO4) rechargeable batteries are a form of lithium-ion (Li-Ion). Increased power output, faster charging, lighter weight and a lengthier lifetime distinguish them from standard cobalt-based Li-Ion batteries. Additionally, the batteries have improved safety features and do not explode under harsh conditions. LiFePO4 batteries also prevent the risk of cobalt entering the environment through inappropriate disposal.

The main distinction between lithium iron phosphate batteries and other lithium-ion batteries is that they can provide a constant voltage and have a higher charge cycle, varying between 2000 to 3000 cycles. LFP batteries are environmentally friendly and are structurally sound. They have a lower discharge rate and a lower energy density. They don't heat up easily and remain cooler than other batteries. The battery's composition safeguards it from thermal runaway, so it's safe for household use.

LFPs have been deployed in vehicles, bicycles, and solar gadgets due to their steady voltage and safe discharge. They're also utilized as a cheaper alternative to expensive lead-acid starter batteries.

They're ideal for applications that demand a high level of current and endurance. Because of their lightweight and ability to deliver massive amounts of energy, they are easy to store and transport. They are commonly found in portable gadgets such as laptops and cell phones.

MIT has recently improved the original lithium iron phosphate cathode material, allowing these batteries to be recharged up to 100 times faster. There are 3 common forms of lithium-ion phosphate batteries:

The best lithium-ion solar battery is one that suits your needs. When choosing a solar battery, the following are some of the most important things to keep in mind:

Battery Capacity

Understanding your power requirements is critical when choosing a lithium-ion solar battery with appropriate energy storage. As a general principle, always estimate your maximum power requirements in amp-hours. For example, a battery with a capacity of 100 amp-hours can potentially produce 1 ampere of electric power for 100 hours or ten amps for 10 hours. You can check out our solar panel calculator to estimate your energy needs.

Round-Trip Efficiency

The quantity of energy that can be computed as a proportion of the energy consumed to store it is the round-trip efficiency of a battery. For example, if 100kWh of electricity is pumped into a battery that can only deliver 90kWh, the battery's round-trip efficiency is 90% (90kWh / 100kWh x 100).

Because they are more cost-effective, always use lithium-ion batteries with a greater round-trip efficiency.