Discovering Solar

A Lithium Tutorial

Hello! Welcome back to the second installation of our Solar Tutorial series. If you haven’t gone through our Solar Components tutorial, we’d highly recommend it. In our previous lesson we’ve learned about the major components of the off grid solar system. Today we will go through the reasons why lithium batteries are
a safer, longer lasting, money saving alternative to your classic deep cycle batteries. But first let’s go through what a deep cycle battery is, and go through the several variations of deep cycle batteries.

What are Deep Cycle Batteries??

Regular batteries commonly found in auto mobiles, output energy differently than deep cycle batteries.
Automotive batteries are designed to output short but large bursts of energy in a very short time. This will suit starting a car, since the amount of energy to start a car tends to have a high demand on a battery. But for off grid, RV, and marine applications, we want to draw power off the battery consistently, in small and even intervals.
Deep cycle batteries are built for this exact purpose. Deep cycles are meant to be depleted at a deeper depth, and recharge easier without damage.

Types of Deep Cycle Batteries

Now that you understand what a deep cell battery is, let's explore the different variations of deep cycle batteries.

Lithium Iron Phosphate

Lithium iron phosphate (commonly known as LifeP04) is the latest technology in battery cells. These are the batteries commonly powering your laptop, phones, and majority of high end rechargeable electronic devices.

Read More About Teragy Lithium >

Lithium Iron Phosphate is the latest technology in battery cells


Absorbed glass mat, otherwise known as AGM are commonly found within automotive applications. In a AGM battery, electrolytes are wicked up into a glass matt internally, so it can never spill. Which offers major safety advances opposed to a flooded lead acid battery.

Flooded Lead Acid

Flooded lead acid batteries are also known as wet cell batteries. These batteries require maintenance, demanding you to add water into the cells to keep the electrolytes happy. Considered old school technology, Flooded or wet cell batteries are still found in automotive applications.

So Why Lithium Batteries?

The decision to purchase lithium over other battery chemistries boils down to cost, usage, and battery size. Let's go through the main benefits below.

700% More Life Cycles. But What Does This Mean?

A single cycle means using the battery from full, all the way down to empty. It is also equivalent to how many times you can charge the battery from empty to full. Think of it as the life span of a battery. AGM, gel, and wet cell batteries, last no longer than 500 full cycles. Teragy lithium batteries are built to last over 3500 cycles. That's like purchasing 7 batteries at the same time!

Teragy lithium batteries are built to last over 3500 cycles

100% More Depth on Discharge. Why Does This Matter?

Depth of discharge matters. In simple English, depth of discharge tells you how much of the battery you're allowed to consume without damaging the battery itself. The assumption is we can discharge a battery 100% every time - that's true, if you're using lithium batteries. With AGM, gel, and wet cell, you're limited to 50% discharge. This means you only get half the storage capacity of what is written on the label.
So what does this mean? Buying lithium gives you 100% more storage capacity than any other battery chemistry. But in reality, you're getting 14x more - if you're considering life span cycles.

More Power, Less Space and Weight

AGM, gel and wet cell batteries weigh 3 times as much as lithium batteries. Because of their discharge rates, they also take up twice the space as well. In mobile, adventure, and off grid applications, space and weight savings is king.

No Maintenance, More Safety

Wet cell chemistry batteries require you to top off the battery for maintenance. In mobile, adventure, and off grid applications, these batteries can spill, causing dangerous fire hazards. Lithium batteries come sealed, dust and water proof, to make sure using your battery doesn't come with a maintenance schedule.

Battery Management System

All off grid, large capacity lithium batteries come with a battery management system (BMS). The BMS helps regulate and balance the charges between the different cells inside the battery, maximizing capacity, shelf life, and safety. Settings like low voltage, high voltage, over temperature, under temperature, and over charge protection insure your battery lasts a lifetime.