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How do you maintain solar batteries?

Solar batteries offer extended functionality for your solar energy system. Being able to store your excess energy, then use it when your system isn’t producing energy is convenient and helpful for your savings. However, solar batteries like any other electronic components will require maintenance. Although, if you’re familiar with any battery-powered electronics like your phone or laptop. Maintaining batteries isn’t as simple as swapping over a few small components. Battery maintenance falls more towards preventative measures than a direct task or action. This is to ensure the longevity of the battery and keep its performance as optimal as possible.

Solar batteries 101

To understand how solar batteries operate in your solar energy system. You will need to know what type of solar batteries your system uses, and whether your solar energy system is grid-tied or off the grid.

Solar batteries or battery banks are an array of interconnected battery units, which function as one large battery. These types of batteries are classified as deep cycle batteries. Deep cycle batteries are meant to provide sustained power over a long period. This is usually till it discharges about 80% of its power and requires recharging. You’ll hear manufacturers saying not to discharge below 45% to extend the battery’s lifespan.

The batteries used can range from lead-acid batteries such as flooded lead-acid (FLA) to sealed absorbed glass mat (AGM). Nowadays, lithium battery units are becoming more common, which come with additional capabilities such as Smart management modules (SMMs) and smart switching.

Maintaining solar batteries

It should be said that maintaining solar batteries should be done in the hands of a professional. Dealing with battery units alone risks personal harm or even death, and damage to your system and home. Even with safety gear, there is always a risk of harm. There is nothing wrong with calling a professional for maintenance help.

You wouldn’t need to do any maintenance on solar batteries that utilize lithium-ion battery units. These units tend to require little to no maintenance over their lifespan. However, if your battery banks include flooded lead-acid batteries (FLA), or valve-regulated lead-acid batteries (VRLA), there are maintenance measures you can take.

Flood Lead-Acid Batteries

Battery terminals can be cleaned with a mixture of baking soda and distilled water with a battery terminal cleaner brush. Be sure to remove the clamps (negative first) before cleaning. After cleaning you can rinse off the mixture and dirt with water. You can make sure all the connections are tight, and even coat the metal with commercial sealant or high-temperature grease if needed.

About 80% of flooded lead-acid battery failures are caused by sulfation. This is when sulfur crystals start to form on the battery’s lead plates. The crystals prevent the chemical reaction of the battery from happening. This occurs because of low charge or electrolyte levels in the battery.

Checking fluid levels can be done by opening the battery and seeing if the fluid is up to the “fill line”. If the battery needs filling, it should only be filled with distilled water. Be careful not to overfill. The maximum amount should be about 1/2″ below the cap. Check the charge level of the battery. Special equipment including a digital voltmeter and a temperature compensating hydrometer is needed. The state of charge or depth of discharge (DOD) will be checked by looking at the battery’s specific gravity and voltage. These need to be checked to make sure your battery doesn’t sulfate heavily.

FLA batteries also require suitable storage conditions, along with proper charging cycles to maintain them. Charging will be handled by your solar energy system’s charge controller. This will ensure your batteries maintain proper charge. However, your batteries will need proper ventilation to prevent hydrogen gas from building up. Hydrogen is flammable when present with oxygen, battery boxes vent out the hydrogen gas through vents and fans around the battery box. Be sure to check these vents and clean them out to keep your batteries running well and safe. FLA batteries should only be placed upright.

Valve-regulated lead-acid (VRLA), Gel, and AGM batteries

These types of batteries don’t require as much maintenance as FLA batteries. These battery units are sealed, so you will not be able to measure the specific gravity of the battery, and fill fluids. VRLA batteries are designed so that these steps are needed. VRLA batteries are more flexible in the storage, as they can be placed on their sides and require less ventilation than FLA batteries.

However, these batteries are sensitive when it comes to the matter of charging. The charging for AGM batteries must be precise and kept as such to make sure they have a decent life span. If an AGM battery’s voltage gets too high, the batteries will heat up. This causes them to release hydrogen gas which permanently damages the cells. This is a common source of failure for gel batteries with their charging voltage sensitivity. Maintaining your charge controller and the voltage going to your batteries will be important in the long term.

Degradation in Solar Batteries

Even with as many preventative measures taken, degradation will still occur in your solar batteries. Just like in solar panels or any other electronic appliance, its performance degrades through usage. In the case of batteries, you’ll see this in smartphones or laptops. Their batteries hold less charge further into their lifespan. For your solar batteries, your warranty period will give you an idea of how long your system is expected to run, and how much performance is guaranteed for that time. Generally with a performance percentage by a certain amount of years.

If you’re looking at the spec sheet and warranty for your solar battery, it’s worth understanding that these are results from controlled conditions. The real-world performance and lifespan of your batteries will depend on several factors:

  • How often are the discharge cycles? 
  • How deep is each discharge cycle of the battery? 
  • What are the operating conditions of your solar battery?

Preventative measures

As mentioned previously, battery maintenance leans toward preventative measures to ensure your battery is running well and smoothly. So what are some of the preventative measures you can take with your solar battery’s operation?

Know your depth of discharge

Knowing your battery’s recommended depth of discharge is important. Different battery types and models have their own recommended depth of discharge amounts. Knowing this will ensure that your batteries don’t overextend their recommended operation and impact their long-term performance.

Manage your charging cycles

Once your battery is discharged, it will need to be recharged to fill it up. This is what’s referred to as a cycle, or charging cycle. Different batteries have different recommended cycles, with lithium-ion batteries designed to cycle daily for optimal use. Your batteries will come with a warranty or recommended lifespan on the number of cycles they can go through.

Proper battery storage solution

A proper battery storage solution is important for the functionality and life span of a battery. Battery units can vary on whether they are suitable for indoor or outdoor placement. They can also vary in regards to their range of operating temperatures. When designing a solar energy system with batteries, we will help design your solar storage system to fit your home without compromising on your system’s performance.

Battery maintenance itself can range from simple preventative measures to hands-on maintenance. Making your batteries operate at their best will be important to make the most out of your solar energy system. Although, battery maintenance should be left in the hands of professionals. Especially if you’re unsure about how to best approach maintaining your solar batteries.

Get started with solar energy today

If you are looking to start your transition to solar energy, we are here to help. Our website also has a free online estimate tool that generates a personalized report for you from a simplified questionnaire. That report will contain the potential savings you can net, and the cost of a solar energy system installed on your property. You can also contact us directly via phone at +1 (602) 363-8919 or via email at Scott@elitesolarenergy.org for more information regarding solar energy for your property.