Have you ever wondered how to pick out the best battery(s) to 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 ensure you get the most bang for your buck)!
When choosing a battery (or batteries) to your solar panel system, there are three categories of batteries which work best. We will do this in 2 parts:
Part 1) Instantly compare the three main kinds of solar batteries (lead acid, saltwater, and lithium). And,
Part 2) Assess the elements 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 ideal battery for your solar panel system!
So let’s get started…
Part 1) The Three Best Types Of Batteries For Solar Panel Systems: The best type of battery for your solar panel system will be dependent on what you’re looking for. 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 are the most commonly used rechargeable battery in the world. They are 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’re the cheapest option but you trade price for some battery life and depth of discharge. But for homeowners needing a great deal of storage for a lesser cost, or if you are just making the transfer to a solar panel system, lead acid batteries may be a very good option. They’re the type of battery we use in the majority 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 remain 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 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) Assess 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 elements to research to find the ideal battery for your system.
Cost 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 may not be the best choice always.
For many systems, a battery will cycle daily, meaning it will drain and charge regularly. With every 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 bear in mind that when you use the maintenance and reconditioning methods we teach you in the EZ Battery Reconditioning application, 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 harming its life. Particular solar batteries can be depleted further than others, allowing for more use between charging. Basically, 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
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 certain 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 operate a large system but only for a short time.
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 charge a battery together with the amount of energy that the charged battery generates.
This may not be a component most would consider, but it is something to focus on. As with other technologies, there are both reputable brands and startup brands. A trusted brand includes known defects and benefits; a startup brand can perhaps have better technology, but can also have yet unknown technological difficulties. Based on your system demands, you may decide to go with a well-reviewed firm or one that is brand new to the market.