Blaise Alexander 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 give you specific things to check on before purchasing your new battery (to ensure you get the most bang for your buck)!

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

Part 1)   Instantly compare the three chief kinds 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 manufacturer.

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

So let’s begin…

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

They are also among the longest-used and most dependable batteries in existence.  Compared to the other batteries we’ll 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 price, or if you are simply making the move to a solar panel system, lead acid batteries may be a very good option.  They’re the sort of battery we use in most of the battery banks within 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 more difficult to come across.  Of the 3 kinds of batteries, saltwater has the greatest depth of discharge, which means you’ll get the most output per charge before needing to recharge.

Lithium batteries are the most expensive and the longest lasting of the three types 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 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) Assess the elements of batteries.  Once you’ve picked 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 ideal battery for 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 buying batteries also.  In some instances though, certain batteries may be overkill for your system so the most expensive battery might not be the best choice always.

Battery Life and Warranty

For most systems, a battery will cycle daily, meaning it will drain and charge regularly.  With each cycle, the battery’s ability to hold the same charge lessens slightly.  So 1 component to consider is the guarantee on the battery which 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 at the EZ Battery Reconditioning program, 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.  Certain solar batteries can 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 save.   Power is how much energy a battery can provide at a certain moment.  A battery with both a high capacity and high power can run a massive system for several hours; a battery with low capacity and higher power can run a large system but only for a brief time.

Efficiency

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

Manufacturer

This might not be a component most would consider, but it’s something to focus on.  Like other technologies, there are both reputable 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.  Based upon your system demands, you might decide to go for a well-reviewed firm or one that is brand new to the market.