Lithium Battery Chargers for Beginners

One technology in the world of solar panels that has seen huge advancements in recent years is the lithium battery. A lithium battery has many advantages over its older counterpart, the lead-acid battery. Not only is a lithium battery safer, but a lithium battery charger also supplies a charge much faster than a lead-acid battery charger.

Lithium batteries weigh less, last longer, and provide more power than a lead-acid battery. Lithium iron phosphate, the battery’s main component, is also more environmentally friendly during the production and recycling phases of its life than lead-acid.

With so many advantages, it’s easy to see why lithium batteries and lithium battery chargers are becoming more popular. Let’s learn more about this setup and how you can utilise it with your solar panel kits.

What is a Lithium Battery Charger?

In the most simple terms, a lithium battery charger is a device that helps to limit voltage to allow you to charge your battery safely. Essentially, the charger takes the energy harnessed by your home solar panel kits, and once it is in the correct current, it collects the voltage in the lithium battery, so you can use it later.

Because of the advancements in its chemical makeup, a lithium battery charger can operate at a higher voltage than other battery chargers and has a longer lifespan. In other words, it can charge your battery faster and a greater number of times than a lead-acid battery.

Can You Charge A Lithium Battery with a Regular Charger?

You can technically hook up your lithium battery bank to a regular charger, and it will charge at a very slow pace. The slow charging speed is due to the use of a lower voltage, which you cannot adjust for safety reasons. If a standard lead-acid battery charged at a voltage that was too high, it would quickly become a fire hazard with the potential for chemical combustion.

Another downfall of using a regular charger for a lithium battery is connected to the low voltage issue. Since regular chargers use lower voltage, they will ultimately only charge your lithium battery to about 80% of its capacity. While that might seem like an inconvenience, it actually lowers the lifespan of the lithium battery by putting undue stress on the lithium.

So even though regular chargers can charge lithium batteries, it’s in your best interest to avoid doing this unless you are really in a bind and have no alternative option.

How Can I Charge a LiFePO4 Battery?

It may sound fairly sci-fi, but LiFePO4 simply stands for lithium iron phosphate battery. Don’t confuse this with a lithium-ion battery (LiCoO2) that is used in smaller electronics and power tools. While the two have similarities, when you want to store energy for larger devices, even small solar panel kits, you’ll need a LiFePO4 battery.

To charge a LiFePO4 battery, you can use solar power, shore power, or an alternator. That’s why lithium batteries are becoming more standard for vehicles like boats and in tiny home solar setups.

Let’s break down the charging process. An external voltage, such as energy from solar panels, will move current from the battery’s anode to its cathode. You can think of it as a pump, but for electrical currents. The lithium battery charger pushes the electric current in the opposite direction than it wants to go when the battery discharges. This movement is what allows you to drive the current into your appliances.

What to Look for When Selecting a Lithium Battery Charger

Just like solar panels, there are lots of different lithium battery chargers out there to choose from. When you’re looking for the right lithium battery charger for your needs, there are four factors to consider:

  • Input Voltage: This should not be more than a specific charge can withstand
  • Output Voltage: This must be compatible with the battery
  • Amp-Hour Rating: This should be the same or higher than your battery
  • Cooling Process: High-quality chargers cool quickly to prevent overheating

These considerations should be simple to determine when reading the specifications of your battery and the lithium battery charger that you are thinking about purchasing. If you can’t find these details easily, it’s better to choose another user-friendly option.

The Lithium Battery Charging Cycle: To Float or Not to Float?

Floating is another major difference between standard lead-acid (SLA) batteries and lithium batteries -- and we don’t mean throwing them in the pool to see whether they sink!

SLA batteries have to be able to enter float mode, which means maintaining the voltage on the battery at a certain level, such as 13.5 volts for a 12V battery. If SLA batteries do not enter float mode, they will overcharge and burn out fairly quickly, so it is a standard design feature on this battery type.

On the other hand, lithium batteries do not need to enter float mode and, therefore, do not need such close monitoring. You can connect your lithium battery without having to worry about it overheating or overcharging. In fact, most lithium batteries can remain unconnected and continue to hold their charge for anywhere from six to twelve months, making them even more appealing for solar energy setups.

Because LiFePO4 batteries provide maximum life when they are between 50% and 80% charged, it’s best to avoid creating a setup that would allow them to enter into float mode, as it could lessen the lifespan of your lithium battery.

The Overview

When determining what sort of solar panel system will be ideal for your circumstances, it’s important to consider your battery bank and what features it should have to maximise your energy levels.

By using the Renogy solar panel calculator, you can calculate how much solar energy your home, RV, or boat will need and then decide which lithium battery and lithium battery charger will provide you with the energy storage you want, along with the safety and efficiency you require.

It’s normal for solar beginners to only focus on the solar panels themselves. Still, your battery storage setup is just as essential to creating a system that will last for decades.