How to Convert Reserve Capacity to Amp Hours

A car battery might offer a 100-minute reserve capacity.
••• Jupiterimages/Photos.com/Getty Images

The reserve capacity of a battery is the number of minutes for which it can run at 25 amps of current without its voltage dropping below 10.5 volts. It roughly describes the amount of energy the battery effectively stores and technically specifies the battery's charge capacity. Voltage relates charge and energy by describing the amount of energy in each coulomb of charge. Ampere-hours is a different unit for describing the same quantity.

    Multiply the reserve capacity by 60 to convert it to seconds. For example, if a battery offers a 100-minute capacity: 100 x 60 = 6,000 seconds.

    Multiply this length of time by 25, which is the battery's amperage. Example: 6,000 x 25 = 150,000. This is the number of coulombs of charge in the battery.

    Divide this answer by 3,600, which is the number of coulombs in an amp-hour. Example: 150,000 / 3,600 = 41.67. This is the number of amp-hours in the battery.

    Tips

    • To convert in a single step, divide the reserve capacity by 2.4.

Related Articles

How to Renew a 12 Volt Battery
How to Convert Amps Into BTUs
How to Convert KWH to KVA
How to Convert Ohms to Kilowatts
Energizer Watt-Hour Battery Specs
How to Convert 12 Volt Alternator to 120 Volts
How to Calculate Millivolts to Amps
How to Calculate KVA to MVA
Parts of a Battery
Lithium-Ion Battery Pros & Cons
Batteries Rely on What to Separate Positive & Negative...
How to Calculate 30 KW to Amps
How to Calculate a Current From the HP & Voltage
How to Calculate Potential Difference
How to Calculate How Long a 9 Volt Battery Will Last
How to Calculate Battery Discharge Rate
How to Convert BTU Per Hour to CFM of Natural Gas
How to Calculate Emf
How to Calculate the Ionization Energy of Atoms
How to Wire a Battery in Series