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Can a Solar Trickle Charger Overcharge a Battery?

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What comes to mind right away when you consider solar trickle chargers? You likely imagined vast fields of panels for industrial use or homes perched on rooftops. Solar panel manufacturers mainly produce smaller and more effective solar panels.

Due to some advancements, we are now able to use smaller panels for a variety of tasks, such as solar battery trickle chargers that let you use the sun to recharge your car battery. These gadgets are an excellent way to maintain accessible battery packs.

Solar trickle chargers charge the battery without the need for an external power source because they are powered by the sun and the battery can be overcharged by a solar trickle charger. Learn more about its purpose and activity in detail here.

What Is Overcharging, exactly?

We should know how batteries function before looking into overcharging. Throughout the day, the solar panels create varying voltages and currents depending on the amount of solar radiation and sunlight.

The extra Ah (amp hour) sent to recharge the battery is overcharging. To reach full charge and avoid sulfation, some overcharging is essential. Overcharging in PV systems can range from 1% to 4%. It’s typical for traditional non-PV cycling systems to charge by at least 10%.

When a sealed battery is overcharged, heat is produced inside the battery. Before a full charge occurs, gassing begins, and as charging continues, it gets worse. In open batteries, gassing is necessary to stir up the electrolyte and prevent stratification, but not to the point where it would use up too much water.

A Solar Trickle Charger Can Overcharge a Battery?

Trickle charging is used to make up for the battery’s capacity loss from self-discharge following a full charge. The battery is maintained in a continuous low-current charge that approaches a fully charged state, to counteract self-discharge.

These models transform solar energy into DC power, which immediately flows to the battery to maintain it charged and thus you can overcharge a battery by using a trickle charger.

What’s a Solar Battery Trickle Charger Maintainer?

A solar battery trickle charger maintainer is a battery charger that runs on solar energy. For many years, trickle imposes have been in use but its solar-powered versions are recent inventions. You might hear about trickle chargers for cars before, but there is more information on that below.

Traditional trickle charges are a little tedious to use because they have to be plugged in all the time. On the other hand, a solar-powered trickle charger only requires that the battery be connected. They are much more adaptable than typical trickle chargers.

The flexible solar panels on the trickle charger will continue to function as long as they are exposed to sunlight. Even when you are far from a power outlet, you can still use solar panels to charge your batteries.

How Do Trickle Chargers for Solar Panels Operate?

It is incredibly simple to use a solar battery trickle charger. There are various battery trickle chargers available, but the battery maintainer is identical to the batteries trickle charger on Renogy. Three parts make up a typical charger, and they are as follows:

  • An adaptable solar panel
  • An inverter and
  • An alligator-clipped wires

Just attach the alligator clips to the positive and negative ends of the battery that you would like to charge. Each pole needs to have one clip. Put the adaptable solar panel in a spot that receives direct sunlight next.

The inverter box might have a tiny “on/off” switch. If that is the case, make sure the switch is in the on position. Remember that not all trickle chargers for solar batteries have these switches. If not, it will start operating automatically as soon as the clips are linked and the panel starts generating electricity.

Can a Solar Panel Overcharge a Battery?

Of course, you can overcharge a battery with a solar panel. 100 Ah (amp hour) lead acid battery linked to a 15 W solar panel that is small in size. This panel didn’t require a charge controller as it is tiny, and the peak current usage is only about 1 A.

Voltage increased up to 18 V may lead to the battery being damaged, and whatever you connect to it will be in danger. Despite recovering, the battery sustained damage. You need to pay attention to two things.

  • Let’s say your battery has a 12-volt 180A/h capacity. This means that your battery requires nearly 2,160 watts to fully charge, and solar cells can overcharge your battery if it can produce more than 2,160 watts throughout the day.
  • Your battery can overchargeif your solar panel can produce more energy than 2,160 watts per day, but if you have a high-quality charge controller, there won’t be a problem. When your battery has been completely charged, the charge controller will stop using solar power.

Batteries come in a wide variety and can be used for a wide range of purposes, from driving a car to powering a flashlight. The battery voltage, current flow, and solar panel voltage all affect how quickly batteries charge. By employing a solar charge controller, you can halt overcharging.

How Long Can Solar Trickle Charger Be Left On Without Overcharging the Batteries?

The light exposure never actually causes any damage to the solar panels. They don’t require covering or sun protection, even though they do age and gradually produce less over time. As for charging batteries too much: That is a problem with the battery charging system, not the solar panel.

Any system that charges batteries with a reasonable amount of power requires a suitable charger or charge controller. When the safe upper voltage minimisation is reached, there ought to be a way to halt current flow into the battery.

You can purchase a PWM (Pulse Width Modulation) solar charge controller. It links the solar panel to the power until the voltage reaches approximately 13.8 volts, at which it disconnects the connection and waits for a slight voltage drop. At that point, it will reconnect and complete the cycle once more.

Does Overcharging Harm the Battery’s Health?

Overcharging causes gassing which is very bad for the battery’s health. It may create heat to build up inside sealed batteries and causes water to leak from open batteries.  Gassing begins before the battery is fully charged and gets worse as charging goes on.

Overcharging lithium-ion batteries can result in thermal runaway and unstable internal conditions, as well as increased pressure.  An excessive amount of current may be pumped into the battery due to an excessive charge voltage. This will result in the electrolyte’s water decomposing and premature ageing.

As the batteries warm up, they will take in more current, which will cause them to heat up even more. This phenomenon, known as thermal runaway, can completely deplete a battery in just a few hours.

The converter and charger must intervene as soon to be a solar battery gets to full charge to handle excess power and reduce risks. They can accomplish this in one of three ways: force a dump load or pull it back into the solar panels for power loss.

How to Stop Solar Panels Overcharging Batteries?

Higher Ah produced by the battery as a result of higher charging voltage from the solar panels ultimately results in overcharging. Controlling the output voltage of the solar panel is the simplest way to prevent excessive battery charging. This can be accomplished by a hybrid inverter.

To prevent overcharging, the power controller’s job is to restrict the battery’s charging voltage. The voltage in the open circuit of a fully charged lead acid battery, which is by far the most popular battery type for automotive applications, is between 12.73V and 12.8V.

By controlling energy flow, the power controller safeguards batteries and solar panels. When batteries are in their entirety, battery charge regulators signal that stops the electricity flow. To guarantee trickle charging and distribute extra charges, many solar energy systems include inverters and chargers.


The missing piece in the energy transition and an essential component of the dwelling’s solar system is batteries. One should be careful to avoid overcharging or completely draining their battery. Based on solar irradiance, the solar panels produce various voltages and currents throughout the day.

The life of the batteries is extended by a hybrid inverter, which prevents overcharging. When overcharged, certain solar batteries run the risk of igniting, heating up, or, at the very least lifespan. So, choose a solar system that handles capacity expansion and handle excess energy effectively for you.