Chip Mullinax Nascar

How To Pick Out The Best Battery For a Solar Panel System, Battery Bank, or Off-Grid System

Have you ever wondered how to pick out the best battery(s) for your solar panel system (or off-grid energy system)? Or have you wondered what makes one deep cycle battery better than another?  If so, this article will answer these questions and provide you specific things to check on before buying your new battery (to ensure you get the most bang for the buck)!

When picking a battery (or batteries) to your solar panel system, there are three categories of batteries that work best.    We will do this in 2 parts:

Part 1)   Quickly compare the three main kinds of solar batteries (lead acid, saltwater, and lithium).   And,

Part 2)   Compare the elements of batteries, such as: depth of discharge, power and capacity, efficiency, battery life, and maker.

By the conclusion of this article you will know just how to pick out the best battery to your own solar panel system!

So let’s get started…

Part 1) The Three Best Types Of Batteries For Solar Panel Systems: The best type of battery for your solar panel system will depend on what you’re looking for. So the first decision to make is the type of battery that will fit your system.

Lead Acid Batteries

They are also one of the longest-used and most dependable batteries in existence.  Compared to the other batteries we will discuss in this report; they’re the cheapest option but you exchange price for some battery life and depth of discharge.  But for homeowners needing a great deal of storage for a lesser cost, or whether you are simply making the move to a solar panel system, lead acid batteries might be a very good option.  They’re the type of battery we use in most of the battery banks in our solar panel systems.

Saltwater batteries are more expensive than lead acid batteries, but also have a greater lifespan.  Unlike lead acid batteries, saltwater batteries are essentially brand new to the industry and stay both somewhat untested and more difficult to come across.  Of the three types of batteries, saltwater has the greatest depth of discharge, so you’ll get the most output per fee before needing to recharge.

Lithium Batteries

Lithium batteries are the most expensive and the longest lasting of the three types of solar batteries.  Comparing all three options, the lithium battery is probably the highest rated, but also the most expensive.  A good example of a lithium ion battery is the Tesla Powerwall.

Part 2) Compare the components of batteries.  As soon as you’ve chosen the best battery type for your solar panel or off-grid system (that meets your system’s needs), there are elements to research to find the perfect battery for your system.  

Cost

Cost is probably one of the more obvious components.  But the old saying,”you get what you pay for” holds true when buying batteries also.  In some instances though, certain batteries could be overkill for your system so the most expensive battery may not be the best choice always.

For most systems, a battery will cycle daily, meaning it will charge and drain regularly.  With each cycle, the battery’s ability to maintain the identical charge lessens slightly.  So 1 component to consider is the warranty on the battery that guarantees a specific number of cycles of useful life.  But keep in mind that if you use the maintenance and reconditioning methods we teach you in the EZ Battery Reconditioning application, you can extend the life of your batteries.

Depth of Discharge

Depth of discharge is how much you can drain the battery before needing to recharge the battery without harming its life.  Particular solar batteries may be depleted further than others, allowing for more use between charging.  Basically, a battery with a 90% depth of discharge per cycle provides more battery power per charge compared to a battery with less.

Capacity and Power

Measured in kilowatt hours (kWh), capacity is the amount of energy a battery can store over time. The more capacity a battery has, the more power it can save.   Power is how much energy that a battery can provide at a certain moment.  A battery with a high capacity and higher power can run a large system for several hours; a battery with low capacity and high power can run a large system but just for a short time.

Efficiency

Efficiency is the amount of energy used compared to the amount of energy it took to store energy.  Batteries require power to control and efficiency compares the energy taken to charge a battery together with the amount of energy which the charged battery generates. 

Manufacturer

This might not be a part most would consider, but it’s something to focus on.  Like other technologies, there are both trusted brands and start-up brands.  A trusted brand comes with known flaws and advantages; a start-up brand can perhaps have better technology, but could also have yet unknown technological issues.  Based on your system demands, you might decide to go with a well-reviewed firm or one that is brand new to the market.