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 buying your new battery (to ensure you get the most bang for your buck)!
When choosing a battery (or batteries) for your solar panel system, there are three categories of batteries that work best. So in this article, we will:
Part 1) Quickly compare the three main types of solar batteries (lead-acid, saltwater, and lithium).
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 out the best 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 depend 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
Lead-acid batteries are the most commonly used rechargeable battery in the world. They’re also among the longest-used and most reliable batteries in existence. Compared to the other batteries we’ll discuss in this report; they are the cheapest option but you trade cost for some battery life and depth of discharge. But for homeowners needing lots of storage for a lower cost, or if you are just making the move to a solar panel system, lead-acid batteries may be a very good option. They’re the type of battery we use in most of the battery banks in our solar panel systems.
Another great thing about lead-acid batteries is that you can use the maintenance and reconditioning methods we teach you in the EZ Battery Reconditioning program to greatly extend lead-acid battery’s lifespan.
- 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 harder to come across. Of the three types of batteries, saltwater has the greatest depth of discharge, so you’ll get the most output per charge before needing to recharge.
- Lithium Batteries
Lithium batteries are the most expensive and 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. An 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 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 is probably one of the more obvious components. But the old saying, “you get what you pay for” holds true when buying 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.
Battery Life and Warranty
For most systems, a battery will cycle daily, meaning it will charge and drain 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 certain number of cycles of useful life. But keep 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
The depth of discharge is how much you can drain the battery down 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 store.
Power is how much energy 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 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 charge and efficiency 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.
This may not be a component most would consider, but it is something to pay attention to. As with other technology, there are both trusted brands and start-up brands. A trusted brand comes with known flaws and benefits; a start-up brand can perhaps have better technology, but can also have yet unknown technological issues. Depending on your system needs, you may decide to go with a well-reviewed company or one that is brand new to the market.
By Jason NG