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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 make certain you get the most bang for your buck)!

When picking a battery (or batteries) to your solar panel system, there are 3 categories of batteries which work best.    We’ll do this in 2 parts:

Part 1)   Instantly compare the three chief types of solar batteries (lead acid, saltwater, and lithium).   And,

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

By the end of this article you will know just how to pick out the ideal battery to your solar panel system!

So let’s begin…

There are three battery types that work exceptionally well; however, each battery type has pros and cons. So the first decision to make is the type of battery that will fit your system.

They’re also one of the longest-used and most dependable batteries in existence.  When compared with the other batteries we will discuss in this report; they are the cheapest option but you trade cost for some battery life and depth of discharge.  But for homeowners needing a great deal of storage for a lower cost, or whether you are just making the transfer to a solar panel system, lead acid batteries might be an excellent 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 basically brand new to the industry and remain both somewhat untested and more difficult to come across.  Of the three types of batteries, saltwater has the best depth of discharge, which means you’ll find the most output per charge before needing to recharge.

Lithium Batteries

Lithium batteries are the most expensive and the longest lasting of the three kinds of solar batteries.  Their depth of discharge is less than that of a saltwater battery, but more than that of a lead acid battery. Comparing all three choices, the lithium ion battery may be the highest rated, but also the most expensive.  A good example of a lithium ion battery is the Tesla Powerwall.

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

Cost

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

Battery Life and Warranty

For many systems, a battery will cycle every day, meaning it will charge and drain regularly.  With each cycle, the battery’s ability to maintain the same charge lessens slightly.  So 1 component to consider is the guarantee on the battery which guarantees a certain number of cycles of useful life.  But bear in mind that when you use the maintenance and reconditioning methods we teach you at the EZ Battery Reconditioning program, you can extend the life of your batteries.

Length of Discharge

Length of release is how much you can drain the battery down before needing to recharge the battery without damaging its life.  Particular solar batteries may be depleted further than others, allowing for more use between charging.  Essentially, 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

The more capacity a battery has, the more power it can save.   Power is how much energy a battery can provide at a given moment.  A battery with a high capacity and high power can run a large system for several hours; a battery with low capacity and higher power can operate a large system but just for a brief time.

Efficiency

Efficiency is the amount of energy used compared to the amount of energy it took to save energy.  Batteries require power to control and efficiency compares the energy taken to control a battery with the amount of energy which the charged battery generates.  The higher the efficiency, the more cost-effective the battery.

Manufacturer

This may not be a component most would consider, but it is something to focus on.  Like other technologies, there are both trusted brands and startup brands.  A trusted brand comes with known defects and benefits; a start-up brand can perhaps have better technology, but can also have yet unknown technological difficulties.  Depending on your system demands, you may decide to go with a well-reviewed firm or one that is brand new to the market.