Multiply these two numbers to get the watt-hour rating (Ah × V = Wh). Note: If the capacity of your battery is expressed in milliampere hours (mAh)—like in the image above— you will need to divide by 1,000 to calculate the ampere-hours (Ah) before multiplying.
What is 100 watt hours mean?
If you have a Light bulb that has a rating of 100 watt, it means that the light bulb consumes 100 J per second. kWh is the unit of energy. You can compare this to the volume of water that comes out of the pipe. A 100 watt light bulb when used for an hour will consume 100 Watt-hour of energy which is 0.1 kWh of energy.
A single 18650 cell is 10 watt hours. You can draw 10 watts from one for 1 hour or 2 watts for two hours. My pack is 140 watt hours so you could draw 20 watts for 7 hours. There is an upper limit for power drain.
The calculation used to determine watt hours is: Example, if the battery you wish to ship is rated at 11.1 volts and 4,400 mAh per cell: • 4,400 mAh is 4,400 milliampere hours. Since most batteries have a low ampere hour ratings, they are rated in milliamperes per hour (mAh), one thousandth of an ampere hour (Ah).
Wh means Watt-hour. 100 Watt-hour battery can deliver 100 watt power for 1 hour, 20 watt power for 5 hours. A 200 Wh battery has more capacity than 100Wh battery for sure. 2. mAh or Ah, means Milliamps Hour (mAh) or Amps Hour (Ah).
A standard small car battery is about 45 amp/hours. That means that it will supply over two amps for 20 hours. A battery should not be discharged at a higher current draw, or asked to deliver more amps than its amp/hour rating divided by 10 in order to get maximum capacity out of it.
This means that a battery has a 100 A.H. capacity if it is discharged over 20 hours, or at about 5 Amps-per-hour (100 A.H. / 20 hours = 5 Amps DC). However, this same battery would last only one hour if the discharge rate was 50 Amps-per-hour (50 Amps DC x 1 hour = 50 A.H.) because of the high rate of discharge.
The energy stored in a battery, called the battery capacity, is measured in either watt-hours (Wh), kilowatt-hours (kWh), or ampere-hours (Ahr). For example, a 12 volt battery with a capacity of 500 Ah battery allows energy storage of approximately 100 Ah x 12 V = 1,200 Wh or 1.2 KWh.
To calculate the energy you will use over time, just multiply the power consumption by the hours of intended use. The 20W TV in this example, on for 2 hours, will take 20 x 2 = 40WH from the battery. Repeat this for all the appliances you wish to use, then add the results to establish total consumption like below.
25 grams of equivalent lithium content are equal to about 300 watt-hours. You can arrive at the number of watt-hours your battery provides if you know how many milliamp hours and volts your battery provides: mAh/1000 x V = wh. Most lithium ion batteries marketed to consumers are below 100 watt-hours (8 grams ELC).
For instance, a 6 volt battery will have 3 cells (3 x2.2= 6.6 volts), a 12 volt battery will have 6 cells (6 x2.2=13.2 volts) and so on.That 2.2 volts is the fully charged, straight off the charger number.
To determine the wattage, use a simple multiplication formula. The ampere (or amps) is the amount of electricity used. Voltage measures the force or pressure of the electricity. The number of watts is equal to amps multiplied by volts.
Your battery energy capacity is 12 volts x 40 amp-hours, for a total of 480 watt-hours. Divide this by 50 watts, and you get 9.6 hours. BUT. This is a car battery, not a deep-discharge marine battery.
Example 1: To convert volts to amps for a 24V VA50 power supply, enter 24 volts and 50 Watts. Click Calculate. Example 2: To convert amps to watts for a 12V DC 500mA power supply, enter 12 volts and .5 amps.
AAA batteries can be measured using voltage for the most part. They are rated at 1.5 volts each and depending on the battery will depend on how much wattage is produced from those volts. It seems on average that AAA batteries have a measurement of a bit less than 2 watts per battery.
Power in Watts = Current in Amps x Voltage. A battery rated for 100 amp hours will provide 5 amps for 20 hours. If we have a 12 volt battery, we multiply 100 by 12 and determine that the battery will provide 1200 watt hours.
So for example an 18650 fully charged is 4 volts…a 20 amp cell can put out 80 watts. In most 2 battery mods, the 2 batteries are in series so they are really putting out 8 volts. Times that by 20 and you get 160 watts.
Cell phones, mobile phones, even smart phones and tablets are very energy efficient because they are designed to run on a battery for a long period of time. Cell Phones use approximately 2 to 6 watts when charging, while a charger left plugged in without a phone will consume 0.1 to 0.5 of a watt.
The watt-hour (symbolized Wh) is a unit of energy equivalent to one watt (1 W) of power expended for one hour (1 h) of time. The watt-hour is not a standard unit in any formal system, but it is commonly used in electrical applications.
The answer is 1000. We assume you are converting between milliampere and watt/volt. 1 ampere is equal to 1000 milliamps, or 1 watt/volt.
Method 1 Estimating Kilowatt Hours from Appliance Labels
- Find the wattage on the appliance label.
- Multiply wattage by hours used each day.
- Divide the result by 1,000.
- Multiply your answer by the number of days you're measuring.
- Multiply by the cost of electricity per kWh.