Battery C Rating

It’s universally true that battery-powered devices won’t stay at 100% capacity forever. Deterioration starts from first use, whether charging or discharging. That’s why consumers commonly ask about their battery’s discharge rate and Battery C Rating when purchasing new devices.

But what is a battery’s discharge rate and where does it come from? 

So, to begin… here are the basics things to know about battery: 

According to Antoine Allanore, a postdoctoral associate from MIT, “A battery is a device that can store electrical energy in the form of chemical energy, and convert that energy into electricity. You cannot catch and store electricity, but you can store electrical energy in the chemicals inside a battery.”

Its 3 Main Components and How Does It Work

The three main components of the battery are anode, cathode, and electrolyte. 

The anode and cathode are two distinct chemicals. Both act as the battery’s terminal. In between these terminals is the electrolyte, a chemical medium that aids in allowing the free flow of electrical charge between the anode and cathode

When used, the battery works once the chemical on the anode delivers the electron to the negative terminal. The ions, that are in the electrolyte, go through an oxidation reaction. Lastly, at the positive terminal, the cathode then waits to accept the electrons. Allowing the stored chemical energy into the eve useful electrical energy. 

For rechargeable batteries such as on phones, cars, or home power backup, the process is different. They are designed to accept electrical energy from an outside source (being plugged into a wall) and put them into its battery’s chemical system to reverse what was lost and restore the charge. 

What is Battery C Rating and How To Get It?

The Battery C Rating is the measurement used to determine the current in which the battery is charging and discharging or how fast the charging and discharging process is. 1C is equivalent to 60 minutes, 2C is equal to 30 minutes, and 0.5 is equal to 120 minutes. 

On that note, the formula is:

t = Time 

Cr = C Rate

To view in hours: t = 1 / Cr

To view in minutes: t = 60 minutes / Cr 

For example, 30C Rate 

• 2,3000mAh Battery 
• 2,300mAh/ 1,000 = 2.3Ah
• 30C X 2.3Ah = 69 Amps 
• 60 / 30C = 2 minutes

The C Rate can be increased or decreased which affects how quick or slow the battery charges and discharges. Provided below is the battery C Rates chart:

Why should we know the battery’s C-Rating? 

It is important as it helps users to determine how long a battery can or will last on any given application. It can also in making an informed decision when buying a device, machine, or gadget. A buyer can look at the capacity and performance of various batteries based on their C Rating, and see which one fits their needs and requirements. 

If a gadget or device requires a lot of power such as a drone or an electric vehicle then it’s going to need a battery with a higher C rating. Having a higher rate meant being able to provide a higher discharge current. But this also means that the battery has a faster rate of wear and tear since it generates heat that can cause internal damage to the battery’s components.

In short, the higher the rating is the battery is likely to have a shorter lifespan. 

Different Battery Types and Their C Rating

To see a product’s battery C-rate, either check the battery’s data sheet or label. Manufacturers can also be contacted if this information is not available. 

There are different kinds of batteries and they are made from different chemistries that affect their rating. 

Sealed lead acid (SLA) batteries (such as those used on Nature’s Generators) have a 0.05C or 20-hour rate. This meant that they have a slow discharge rate. Meanwhile, Lithium iron phosphate batteries have a higher discharge rate at 1C. 

Another key difference between the two is their power usage. The SLA’s power delivery is affected by how much energy is left in its tank when used. Meanwhile, the Lithium battery gives the same amount of energy when used.

Factors that Affect a Battery’s Discharge Time and Efficiency

Besides every day use, the battery’s discharge time is also affected by a few external factors, whether they are Lithium or Lead acid, such as: 

•    Maintenance and Usage – Battery degradation is a natural occurrence. But, it doesn’t mean that one should be reckless or mindless when using a gadget/device. Proper usage and regular maintenance can go a long way in making sure the longevity of any battery.  
•    Cyclic Life – Plays a main role in determining how the battery’s life is going to be. An AGM battery can have a life cycle of 300 – 700 when used normally. A complete cycle happens once is charged and discharged. So, for those with a solar-powered system, one cycle corresponds to a day since it charges during the day and discharges at night. 
•    Temperature – Is everything. This plays a crucial role in the battery’s performance, charging, and shelf life. The temperature should just be right in the middle. Not too cold. Not too hot. If it’s too hot, there are more chemical activities inside which reduces the battery’s cyclic life. The recommended temperature for most batteries is between 65-90 F.
•    Depth of Discharge (DOD) – Like a human body, if a battery works harder than it usually does then the likelihood of it breaking down faster. 
•    Battery Chemistry – Since batteries are made of different chemicals, their ability to keep and provide power degrades over time. 
•    Application – If you’re using the incorrect type of battery then expect it to fail quickly. So, it’s imperative to pick the right kind. One can’t pick a sword during a gun battle. It’s going to be a disaster from the get-go.  

Knowing the battery C rating plays a big role in good battery management. It meant the avoidance of overcharging and discharging and easy tracking of battery health. But consistency and being on top of things is also needed to take advantage of this information.

More importantly, it also gives the consumer the opportunity to make an informed decision when buying gadgets, vehicles, solar generators, or any devices for that matter. 

 * We want to give credit where credit is due. Professional writer, Cris Ilao, contributed research and content to this blog titled: Battery C Rating Thank you, Cris, for your contributions!