Lithium-ion batteries have a significantly longer lifespan than lead acid batteries, but their initial cost is much more expensive. Lead acid batteries can take upward of 10 hours to charge, whereas lithium-ion batteries can charge between a few minutes and three hours.
There are several solar battery options available to power your home’s energy source. Two common types are lithium-ion and lead acid, and while these batteries have similar purposes, their cost, lifespan, and efficiency differ. To help you feel confident in choosing a lead acid vs. lithium-ion battery, let’s go over their definitions, how they work, and which battery to pick for your living situation.
What are Lithium-ion Batteries?
Lithium-ion is a rechargeable battery that stores energy through the reversible reduction of ions. As the name suggests, lithium-ion batteries consist of the metal lithium. Due to the battery's exceptional technology, it also powers smart devices like cell phones and laptops.
What are Lead Acid Batteries?
Lead acid batteries use lead and sulphuric acid to function and are the first type of battery ever invented, dating back to 1859. These batteries release energy to heat engines until they kick start — they are commonly used to power vehicles and solar systems.
Types of Batteries
When it comes to power, you have a few types of batteries to choose from. Let’s plug into the three common battery options.
- Flooded Lead Acid (FLA): The type of battery with the longest lifespan and lowest cost. However, they request routine maintenance of watering, charges, and cleaning their terminals.
- Sealed Lead Acid (SLA): A rechargeable battery that requires little to no maintenance. Their spill-proof features are desirable, but gel SLA batteries can’t handle large charge currents, so they output less energy, and take longer to charge.
- Lithium: A type of battery that requires little to no maintenance, but has a higher initial price tag. Perfect for solar systems because they produce more energy, and their efficiency can lead to lower spending over the battery’s lifespan.
How Do Lithium-ion Batteries Work?
In simplest terms, lithium-ion batteries work due to the movement of electrons. When lithium ions move, they create a charge at the positive current receiver. This electrical current then moves from the current receiver of the device needing power (cell phone, laptop, etc.) to the battery.
How Do Lead Acid Batteries Work?
Lead acid batteries work similarly to lithium-ion batteries by releasing electrons while storing a power charge. While the process is very similar, the material is different. Instead of lithium, this battery uses lead and sulphuric acid to create a chemical reaction and produce electricity.
Lithium-ion and Lead Acid Battery Comparison
When it comes to a lead acid battery vs. a lithium-ion battery, there are many similarities (including their energy process), but there are also differences. Below we compare both types of batteries.
|Capacity||15+ kWh||< 5kWh|
|Depth of discharge||80+%||50%|
|Lifespan||10+ years||3-12 years|
When it comes to the price tag, the lead acid battery overpowers lithium-ion batteries. The starting rate for lead acid batteries is roughly $500, whereas lithium-ion batteries start at $5,000 and can cost upward of $15,000 after installation. The size of your system will determine the exact cost of your battery.
While the initial cost of lead acid batteries stomps on the hefty price tag of lithium-ion batteries, the overall lifespan holds a higher power.
Would you rather spend less money now, and replace your battery significantly faster, or spend more money upfront, and enjoy the benefits of 10-15 years of battery life? You’ll need to consider this when deciding between a lead acid battery and lithium-ion.
A battery's capacity is how much energy it can store and discharge. Lithium-ion batteries are known for holding more power than lead acid batteries. The starting capacity of lithium-ion batteries is 15 kWh, whereas lead acid batteries can hold less than 5 kWh. However, the exact capacity of a battery will vary depending on the make, model, and manufacturer.
Depth of Discharge
The depth of discharge is the percentage of energy flowing in and out of the battery per cycle. Lithium-ion batteries have an 80+% depth of discharge compared to the 50% maximum depth of discharge for lead acid batteries. When lead acid batteries discharge over 50%, it can negatively affect their lifespan.
In terms of batteries, the efficiency is the amount of energy a battery receives during the charging process compared to the amount of charge you can extract from it.
The efficiency of both types of batteries is fairly similar, but lithium-ion batteries have slightly more than lead acid batteries. Lithium-ion batteries have an average efficiency of 95% or more. On the other hand, lead acid batteries have roughly 80-85% efficiency.
Just like almost everything else in life, batteries lose their spark over time. Every time a battery drains and then recharges, that counts as a single cycle. Lithium-ion batteries tend to last 10+ years, whereas lead acid batteries last between 3-12 years.
Lead Acid Battery vs. Lithium-ion: Which Battery Should You Choose?
Now that you are more familiar with how each battery stacks up, let’s jump into which type you should choose for each living situation.
Full-Time Off-Grid Residence
Folks who live off the grid full-time would benefit from lithium-ion batteries or flooded lead acid if they don’t mind routine maintenance. For heavier battery use, lithium-ion would be the best bet.
Off-Grid Cabin / Vacation Home
Cabin and vacation homeowners who aren’t using their properties full time should opt for sealed lead acid batteries since they don’t require as much maintenance as FLA batteries. When you choose SLA batteries, you don’t have to worry about them dying if they are idle for a few months out of the year.
Battery Backup System
People looking for a backup battery solution in case of emergency should choose sealed lead acid batteries. Since you’ll most likely only need the backup if you live in an unreliable power grid, the investment in a lithium battery isn’t worth it. You’ll want to utilize lithium to its full potential to justify the cost. The routine maintenance with flooded lead acid batteries require is also something you won’t want to deal with.
Remote Industrial Use
Industrial centers can benefit from both lithium-ion batteries and lead acid batteries — the decision will depend on usage and equipment. If you are powering a site that requires a lot of energy, then lithium-ion batteries are worth it. However, if you are powering basic equipment, sealed lead acid batteries can get the job done at a fraction of the cost.
Lead Acid Battery vs. Lithium-ion FAQ
Choosing between a lead acid battery vs. lithium ion can be tough. Here are a few answers to common battery questions to help you make your decision.
What Is the Difference Between a Lithium Battery and a Lithium-ion Battery?
Lithium batteries are single-use, whereas lithium-ion batteries are rechargeable. Also, lithium batteries have four times the amount of lithium-ion batteries and are less expensive to make and buy.
What Are the Disadvantages of Lithium-ion Batteries?
The high initial cost of lithium-ion batteries is one of the main disadvantages of this type of battery. Lithium-ion batteries have a long lifespan, but they do not last forever.
Is Lead Acid or Lithium-ion Safer?
Lithium-ion batteries are safer than lead acid batteries. If lead acid batteries spill, they are classified as dangerous according to the Electronic Code of Federal Regulations.
Can I Replace a Lead Acid Battery With Lithium-ion?
Yes, you can replace a lead acid battery with a lithium-ion battery, but the cost might be significant. Both batteries work to provide energy and are interchangeable, but it’s important to consider your exact needs, budget, and environment.
You have a lot to consider when choosing between a lead acid battery vs. a lithium-ion battery. While the cost of lead acid batteries is significantly less than lithium-ion, their energy capacities are far more different. Make sure to consider whether you are living fully off the grid or need power for industrial purposes when choosing your type of battery.
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