Can You Fix A Car Battery

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

Or have you wondered what makes one deep cycle battery greater 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) for your solar panel system, there are 3 categories of batteries which work best.    We will do this in two parts:

Part 1)   Quickly compare the three main types 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 manufacturer.

By the end of the article you will know just how to pick out the ideal battery to your own 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.

Lead Acid Batteries

They are also among the longest-used and most reliable batteries in existence.  Compared to the other batteries we will discuss in this report; they are 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 whether you are just making the move to a solar panel system, lead acid batteries might be a very good option.  They’re the sort of battery we use in most of the battery banks in our solar panel systems.

Saltwater Batteries

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 market and remain both somewhat untested and more difficult to come across.  Of the 3 types of batteries, saltwater has the greatest depth of discharge, so 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 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 ion battery may be the highest rated, but also the most expensive.  A good example of a lithium battery is the Tesla Powerwall.

Part 2) Compare the components 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 research to find the ideal 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.  Sometimes though, certain batteries could be overkill for your system so the most expensive battery may not be the ideal choice always.

Battery Life and Warranty

For many systems, a battery will cycle daily, meaning it is going to drain and charge regularly.  With each cycle, the battery’s ability to hold the same charge lessens slightly.  So one component to consider is the warranty on the battery that guarantees a specific number of cycles of useful life.  But bear in mind that if you use the maintenance and reconditioning methods we teach you in 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 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 will provide more battery power per charge than a battery with less.

Ability 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 given moment.  A battery with both a high capacity and high power can run a large system for several hours; a battery with low capacity and high 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. 

Manufacturer

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