1962 Vw Dune Buggy

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 report will answer these questions and provide you specific things to check on before purchasing your new battery (to make certain you get the most bang for the buck)!

When choosing 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)   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, capacity and power, efficiency, battery life, and manufacturer.

By the end of the article you will know exactly how to pick out the best battery for your own solar panel system!

So let’s get started…

So the first decision to make is the type of battery that will fit your system.

Lead Acid Batteries

Lead acid batteries are the most commonly used rechargeable battery in the world. They are also one of the longest-used and most reliable batteries in existence.  When compared with the other batteries we’ll discuss in this report; they’re the cheapest option but you exchange cost for some battery life and depth of discharge.  But for homeowners needing a great deal of storage for a lesser price, or if you are simply making the move to a solar panel system, lead acid batteries may be an excellent option.  They’re the type of battery we use in the majority of the battery banks in our solar panel systems.

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

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 battery may be the highest rated, but also the most expensive.  An example of a lithium ion battery is the Tesla Powerwall.

Part 2) Compare the components of batteries.  As soon as you’ve picked 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 elements.  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 might not be the best choice always.

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

Length of Discharge

Depth of discharge is how much you can drain the battery before needing to recharge the battery without harming its life.  Certain 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 will provide more battery power per charge than 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 store.   Power is how much energy that a battery can provide at a given moment.  A battery with both a high capacity and higher power can run a massive system for many hours; a battery with low capacity and higher power can run a large system but only for a short time.

Efficiency

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

Manufacturer

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