What is C rating in the Battery Means for home Inverter/UPS?

What does the C rating in the Battery mean for home Inverter/UPS? The C rating in a battery measures how fast the Battery can be discharged. It is calculated by dividing the Battery’s capacity by the discharge current.

For example, a battery with a capacity of 100Ah and a C rating of 1C can be discharged at a rate of 100 amps for one hour. This means the Battery can provide 1000 watts of power for one hour.

A higher C rating means the Battery can be discharged with a higher discharged current, and the backup time will be according to the C rating. This means the Battery is designed for the C1 rating, and one can discharge the C1 rating, and it will give the backup for exactly one hour of 1000 watts, and life will be defined as the cycle life by the manufacturer.https://batteryuniversity.com/article/bu-402-what-is-c-rate

The C rating is important when choosing a battery for a specific application. For example, if you need a battery that can provide a lot of power for a short period, you would need a battery with a high C-rate. If you need a battery that will be required for running bigger or smaller loads accordingly, you choose the higher or lower C-rate Battery.https://suvastika.com/difference-between-c20-and-c10-tubular-battery/

Here is a table summarizing the different C-rates and their corresponding discharge times:

C-rate Discharge time
C1 1 hour
C2 30 minutes
C5 12 minutes
C10 6 minutes
C20 3 minutes
C100 1 minute

Lithium-ion batteries can generally be discharged at higher C-rates than lead-acid batteries. This is why lithium-ion or Lithium LifePO4 batteries are often used in applications where a fast discharge rate is required, such as electric vehicles, solar power and Inverter/UPS applications.https://suvastika.com/tubular-battery-is-c20-and-c10-and-lithium-battery-is-c1-capacity/

Here are some examples of C ratings for different types of batteries:

  • Lithium-ion battery: 1C to 5C
  • Lead-acid Battery: 0.1C to 0.5C
  • NiMH battery: 0.5C to 1C
  • NiCd battery: 0.5C to 1C

The C-rate Battery required for running the home or office load depends on the backup time and the power capacity. So, for example, if we have a 1000-watt load for the home to run and choose a C20 Tubular Lead Acid battery capacity of 150 Ah, then our backup time will be approximately less than 40 minutes. But if our Load is 400 watts, the same Battery will give approximately 3 hours as the C20 Tubular battery is designed to discharge the 7.5 Amps. Suppose we discharge the Battery for 90 watts of the Load. Theoretically, it should give 20 hours of backup as the C20 rating denotes the value at which the Battery should be ideally discharged to get maximum efficiency. But if we discharge at higher loads, the battery capacity and life will fall. One can see the tubular Lead Acid battery 150 Ah chart and what kind of Load and the backup time one will get. This chart is made at Su-vastika after many battery tests on home Inverters/UPS available in the Indian market. Otherwise, the user is always confused along with the reseller on how to calculate the real back p time, which is a big challenge for everyone from the seller to the user. Also, we tested the C1 Lithium LifePo4 battery, checked the backup time using the same Inverter/UPS, and made the results for your convenience. If you are using the Inverter/UPS or solar backup application, this result helps the user choose the right Battery per their needs and budget.

C10 Rated 150Ah & 200Ah battery Backup

C10 Rated 150Ah & 200Ah battery Backup


C20 Rated 150Ah & 200Ah battery backup

C20 Rated 150Ah & 200Ah battery backup

If your home load is larger or the power outage’s expected duration is longer, you may need a battery with a higher C rating. For example, a C20 battery can be discharged at 5% of its capacity per hour. This means a 150Ah tubular battery with a C20 rating can provide 7.5 amps of power for 20 hours.

It is important to note that discharging a battery at a high C rate can reduce its lifespan. Therefore, it is best to choose a battery with a C rating that is appropriate for your needs.

Here are some factors to consider when choosing a C-rate battery for running a home load:

  • Size of the home load: The larger the home load, the higher the C rating of the Battery you will need.
  • Expected power outage duration: The longer the power outage duration, the higher the C rating of the Battery you will need.
  • Battery type: Different battery types have different C ratings. Lithium-ion batteries can typically be discharged at higher C rates than Tubular lead-acid batteries.
  • Battery cost: Batteries with higher C ratings are typically more expensive than batteries with lower C ratings. but they can provide you with higher Load and life compared to lower C rating batteries.

It is important to consult with a battery expert to choose the right C-rate battery for your home or office load.

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *