Solar Battery Charging: How it Works, Problems and Solutions

How does solar battery charging work? This article explores the basics of setting up a PV storage system, the parts involved, and what to do when things aren’t working correctly. This also includes how to use power from the grid to charge solar cells when necessary, such as during inclement weather and other important information.

How do Solar Battery Chargers Work?

A solar-to-battery charger forms the link between the solar energy-producing array and the energy storage system, which, in this case, is the battery or bank of batteries. When the variety actively produces energy, the charge controller also decides when to and when not to charge.

The charger can control the power used to charge the battery and manage the entire process. This helps ensure that safety occurs without risk to the battery.

Today, a solar battery charge controller is an intelligent device that monitors the system and optimizes the charging based on several parameters, such as available charge and array voltage or current. To help you understand how this happens, we have compiled everything about solar battery charging below.

Solar Battery Charging

Charging your battery involves several stages and includes different parts of the PV system. This is called the charging system. As you’ll learn below, the solar battery charging process is also a controlled chain of events to prevent damage.

Solar Battery Charging System

The solar battery charging system is only complete if these components are in working order: the array or panels, the charge controller, and the batteries. Here is what happens right from when sunlight hits the panel to when the battery receives and stores energy:

Solar Battery Charging Voltage

The charging voltage must be adequately regulated for the solar charging process to happen smoothly. The charge controller does this. Depending on the type, it intelligently monitors the power from the array, regulating it to make it suitable for the type of storage system or condition.

Solar Battery Overcharge Protection

Your solar battery can only hold its rated amount of energy. If unchecked, it would overcharge and get damaged. The charging controller is tasked with ensuring that doesn’t happen by offering what’s called solar battery overcharge protection.

As earlier indicated, it’s always monitoring both the battery and the charging process and will stop the charging when capacity is attained.

Solar Battery Discharge

After charging, your solar battery is ready to supply the stored energy. This is called discharging. Just like charging, the solar battery discharge process must be regulated, or the battery will discharge too much and get damaged. But how long can you expect a charged battery to last? Let’s see.

How Long Does a Fully Charged Solar Battery Last?

It depends on the battery’s size or capacity and C-rating. A C-rating describes the discharge rate or, in other words, the amount of stored energy that your battery is cable of providing over a specified period. For instance, a C10 rating means the battery will take ten hr. to discharge fully.

Solar Battery Over Discharge

Solar battery over-discharge describes a situation where the battery discharges beyond its DOD or depth of discharge. In a normal protected system with a charge controller, this cannot possibly happen. Note that different types of solar batteries allow different levels of discharge depths. For example, a lead acid battery’s DoD is 50%, while that of a Li-Ion type is 80%.

Can a Solar Battery Be Charged with Electricity?

It can. However, you need to have the necessary components and connections in place, as this means linking the battery or batteries to your service line. This must be safely done. With this system, you get to ensure your batteries are always charged, even when the panels cannot supply enough power.

How to Charge Solar Battery with Electricity

Here’s how to charge a solar battery with electricity: First, you would need to connect it to the grid. This arrangement is commonly called a hybrid system. In addition to storing excess energy in the batteries, you can send it to the grid whenever necessary. Likewise, it also means you can use the utility or service line power to recharge your batteries.

Hybrid Inverter with Solar Battery Charging System

The load circuits are connected to the grid and storage system in a hybrid PV system. That typically requires a hybrid inverter. A hybrid inverter with a solar battery charging system works both ways: it converts DC power to AC before feeding it to the grid and the grid’s AC to DC when setting the storage system.

Solar Battery Charging Problems

Just like any other electrical system, your solar battery charging system can fail and start to experience problems. These often involve issues with the battery not accessing or holding charge.

Note that these do not always mean a failed system; they can also indicate a bad battery. The solar battery charging problems and their solutions are discussed below.

Solar Battery Not Charging

A solar battery not charging can indicate issues with many things: improper wiring, faulty charging components such as charger controllers, panels, or even the battery itself.

The best way to solve that is by checking each part individually and taking measures to replace them if required. Sometimes, the remedy is as simple as resetting an improperly set charging controller.

Solar Battery Not Holding Charge

The solar battery is not holding a charge for long enough. This can result from any of these problems: a battery that’s come to the end of its useful service life or a battery that was incorrectly sized. Solve these charging problems by doing one of the following:

Confirm that you have the right kind of battery (in terms of size) for your usage levels. If the battery is too old, consider having a new one installed in its place. Generally, a solar battery replacement is necessary when it can only charge up to 80% of its rated capacity.

Conclusion

Solar battery charging is necessary when you have backup storage in your PV installation. If it isn’t happening safely and as required, you do not have an energy storage solution you can rely on. So it becomes necessary to understand how it works so that you can spot problems early enough. That’s in addition to ensuring its proper setup in the first place.