3 Best Batteries for a Backup Home Energy System
When designing wind, solar or another alternative energy system what are the best batteries that you can use?
Because of the falling prices of renewable energy systems, more and more people
are looking to use alternative energy sources as a way to:
- Save a little money
- Become energy independent
- Break their dependence on the big energy companies
Unfortunately installing a renewable energy system, requires you to make a considerable investment that you may not recoup in several years. One of the biggest expenses associated with alternative energy systems is the batteries used in the battery bank. This makes choosing the correct batteries for your off-grid system crucial (and keeping the batteries alive as long as possible is also very important)!
So, In this article, I am going to try to answer this question in an effortless and straightforward way.
I will discuss the following topics:
- lead-acid batteries VS. Other battery technologies in a battery bank
- deep cycle vs. shallow cycle batteries in a battery bank
- flooded lead-acid batteries (FLA) VS sealed lead-acid batteries (SLA) in a battery bank
- Last but not least, the three batteries we recommend for your off-grid power system in your household (based on the criteria we cover in this article)
Lead-acid batteries vs. other battery technologies
Many of the batteries used in renewable energy systems were originally designed for other purposes. The most prominent example is the lead-acid battery, which has long dominated industry.
For these reasons, deep-cycle lead-acid batteries have proven to be one of the best (and most affordable) battery types for battery banks in alternative energy systems:
- They can withstand frequent discharges.
- They are more cost-effective than other types of batteries.
- They have more robust durability in a battery bank
- They perform more consistently than other batteries
The fact that they are manufactured on a large scale also means that they are relatively easy to replace when a battery in your battery bank needs goes bad.
Watch our free presentation to learn how you can bring old batteries back to life.
It should be noted; however, that lithium-ion batteries for alternative energy systems in private households such as Tesla’s Powerwall have been gaining ground recently – but the initial investment in lithium-ion batteries is still much higher than the initial investment in lead-acid batteries.
The power wall may change this at some point, but for now, deep cycle lead-acid batteries are the most cost-effective and, therefore, the most practical solution for a home battery bank.
Deep cycle vs. shallow Cycle (car) Batteries
Back then, when the renewable energy sector was still in full swing, people who wanted to go completely off the grid often had to get creative because the only thing available were car batteries.
Unfortunately, car batteries were never built for this purpose and should not be drained continuously and recharged (which they have to do in a solar panel or wind turbine set up).
Car batteries should only be used for starting and ignition. If you take a look inside, you will see that they have a large number of thin plates.
These plates have a large surface area that can handle multiple instances of chemical reactions. When you turn the key to start your car, these reactions produce the sudden burst of energy needed for ignition.
Deep-cycle batteries, on the other hand, have thick lead plates that do not provide much room for chemical reactions. Although they generate less power, they are designed to do so over a much more extended period of time.
Essentially, car batteries are “flat cycle” batteries that burn out quickly when used as a storage for renewable energy.
Flooded Lead-Acid Batteries (FLA) VS Sealed Lead-Acid Batteries (SLA)
Before I tell you which three batteries are best suited for alternative energy system battery banks, it should be made clear why flooded lead-acid batteries (FLA’s) are better suited for renewable energies than sealed lead-acid batteries (SLAs).
The main reason why some people prefer SLAs is that they require only small amounts of maintenance lead-acid batteries, unlike FLAs, which need to be checked regularly for water levels. SLA’s that are used correctly can be left alone.
However, sealed lead-acid batteries have two major shortcomings: they are sensitive and wear out quickly. So if you plan to use your solar panel or wind power system every day, this will ultimately be a problem.
So here are the categories of flooded lead-acid batteries that are best suited for an off-the-grid power system.
The 3 Best Batteries
Now that we know that we want a lead-acid battery, it is flooded (FLA), and also has deep cycle characteristics …here are our 3 favorite batteries for an off-grid battery bank:
1) Golf Cart Batteries
Golf cart batteries are the most widely used manufactured batteries on this list. They also work great in an alternative application of the energy system. So it’s not surprising that they are one of the most frequently-used batteries in the battery banks for renewable energy systems.
Even though the five to six-year life of golf cart batteries is relatively short golf cart batteries more than makeup for their lack in this area are extremely durable and inexpensive.
Furthermore, golf cart batteries can be found almost everywhere, which makes them a good battery bank choice.
If you really desire to build a high quality but inexpensive battery bank, then one of the
The best option is:
- to get old or “empty” batteries from golf courses or golf cart shops for free or dirt cheap (just call them and ask if you can have their old batteries probably lying around, overloading their store)
- These batteries can then restored to as-new condition with a reconditioning system like that forund in the EZ Battery reconditioning program
- Use the reconditioned batteries in your battery bank
2) Industrial or Forklift Batteries
A battery bank containing one or more industrial batteries is the opposite of the golf cart philosophy used for a battery bank. Instead of relying on several strings of smaller batteries, you use just a few or even a single battery to store all your energy. Since these batteries are not usually manufactured in standard sizes, a solution must be found that meets your specific needs.
You can also try to find an old industrial or forklift battery that is the right size for your system and use it. As with golf cart batteries, there are sometimes ways to get free or cheap forklift batteries. One possibility is to call or visit industrial companies and see if they have old or “empty” forklift batteries. Offer to dispose of them or pay a little for them. If they agree then you can recondition the battery and use it instead of an expensive new one. However, if you decide to buy a new custom battery instead, you should expect to pay quite a lot. But the good news is that these types of batteries are typically built to last 15 to 20 years.
Other things to consider are:
- These larger batteries will be heavier and harder to move.
- There could be advances in battery technology that could render the battery obsolete in the coming years.
But if you don’t mind making a considerable investment in advance (anywhere from $2,000 to $10,000) and have no problem keeping your batteries in peak condition, then industrial batteries could be a better choice.
3) L16 batteries
If you would like batteries that have more capacity than golf cart batteries but do not want to be used for industrial batteries, L16 batteries are a good Middle ground.
These flooded lead-acid batteries were originally developed for supermarket floors scrubbers.
The nice feature about these batteries is that they last a little longer than golf carts batteries – about six to eight years longer actually. However, they can be twice as heavy and the 6-volt models can be twice as expensive.
Different households have different energy requirements and need battery banks which are dimensioned accordingly.
If you build a battery bank with one of the three batteries I addressed in this article, you should be able to create a battery bank that meets your exact needs.
Lately, there are some exciting new developments in the world of batteries for alternative Energy. These new products should come onto the market in the next few years years, like the lithium-ion Tesla power wall.
But currently, our three favorite batteries for off-grid energy systems in private households, alternative energy systems are golf cart batteries, L16 batteries, and industrial batteries.
If you are interested in saving money and making your battery bank more affordable, you can use a do-it-yourself type of system like the EZ battery reconditioning program and learn how to:
- Get old or “dead” golf cart batteries, L16 batteries or industrial batteries for free or dirt cheap
- Recondition them to 100% of their operating condition
- Use these “as good as new” batteries instead of buying new, overpriced batteries in order to save a lot of money!