Makita Battery Fixing Gun

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 buying your new battery (to ensure you get the most bang for the buck)!

When choosing a battery (or batteries) to your solar panel system, there are three categories of batteries that work best.    We’ll do this in two 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 manufacturer.

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

So let’s begin…

So the first decision to make is the sort 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.  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 lots 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 sort 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.  Contrary to lead acid batteries, saltwater batteries are essentially brand new to the industry and remain both somewhat untested and harder to come across.  Of the 3 kinds of batteries, saltwater has the greatest depth of discharge, so you’ll find the most output per fee 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 ion battery is probably the highest rated, but also the most expensive.  An example of a lithium battery is the Tesla Powerwall.

Part 2) Assess 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

Price is probably one of the more obvious elements.  But the old saying,”you get what you pay for” holds true when purchasing batteries as well.  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 many systems, a battery will cycle every day, meaning it is going to 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 warranty 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 application, you can extend the life of your batteries.

Depth 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 can 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.

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 store.   Power is how much energy a battery can provide at a certain moment.  A battery with a high capacity and high power can run a large system for many hours; a battery with low capacity and high power can run 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 said energy.  Batteries require power to control and efficacy compares the energy taken to control a battery together with the amount of energy which the charged battery produces.  The higher the efficiency, the more cost-effective the battery.

Manufacturer

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