Energy of a Car Battery
An educational, fair use website
| Bibliographic Entry | Result (w/surrounding text) |
Standardized Result |
|---|---|---|
| Berger, John J. Charging Ahead: The Business of Renewable Energy and What it means for America. Canada: Fitzhenry & Whiteside Ltd., 1997: 287. | "But today's lead-acid batteries have only about 30 watt-hours of energy per kilogram, and need to be replaced every two or three years, or after as few as 15,000-20,000 miles." | 0.6–7.3 MJ |
| Sonnenschein Prevailer Dryfit German DF Series SLA GEL Batteries. Battery Web. | [see below] | 2.1–8.6 MJ |
| Optima Batteries. Battery Web. | [see below] | 2.1–4.8 MJ |
A battery is a device that converts chemical energy into electrical energy. A dry-cell flashlight battery consists of an electric cell, but larger batteries are made up of a group of cells that are connected to act as a source of direct electric at a given voltage. A cell consists of two dissimilar substances, a positive electrode and a negative electrode, that conduct electricity, and a third substance, an electrolyte, that acts chemically on the electrodes. A group of several such cells connected together is called a battery. Batteries are widely used as a source of direct current electrical energy in automobiles, boats, aircraft, portable electric and electronic equipment, and lightning. A car battery is used mainly to start the motor. Once the motor is running, an alternator supplies current to recharge the battery. A few car battery companies include Diehard and Trojan.
The formula for determining battery energy is:
E = P·t = V·I·t
Where
I = Current Expressed in amperes
V = Electromotive force expressed in volts
P = Power expressed in watts
t = Time expressed in hours
E = Energy in joule
For Car Batteries:
Source: Sonnenschein Prevailer Dryfit German DF Series SLA GEL Batteries. Battery Web.
| Model | Volts | Ah at 20 hours | Weight (lb.) |
|---|---|---|---|
| DF115 | 12 | 50 | 39 |
| DF125 | 12 | 55 | 42 |
| DF150 | 12 | 50 | 51 |
| DF180 | 12 | 85 | 66 |
| DF230 | 12 | 110 | 82 |
| DF25 | 12 | 15 | 13 |
| DF45 | 12 | 30 | 23 |
| DF4D | 12 | 165 | 106 |
| DF4DLT | 12 | 95 | 86 |
| DF6V180 | 6 | 200 | 67 |
| DF75 | 12 | 42 | 27 |
| DF8D | 12 | 200 | 150 |
DF115: (50 Ah) × (12 V) × (3600 s) = 2,160,000 J
DF180: (85 Ah) × (12 V) × (3600 s) = 3,678,000 J
DF8D: (200 Ah) × (12 V) × (3600 s) = 8,640,000 J
Source: Optima Batteries. Battery Web.
| Model | Volts | Ah | Weight (lb.) |
|---|---|---|---|
| 34/78/800U | 12 | 50 | 39 |
| 34/800S | 12 | 50 | 38 |
| 34M/1000M | 12 | 50 | 39 |
| 6V/850/6 | 6 | 50 | 19 |
| 75/35-925 | 12 | 44 | 34 |
| D34/78/D750U | 12 | 55 | 44 |
| D34/D750S | 12 | 55 | 43 |
| D34M/D900M | 12 | 55 | 44 |
| D6V/D750/6 | 6 | 50 | 24 |
| R34/800R | 12 | 50 | 38 |
| TF | 12 | 110 | 90 |
34/800S: (50 Ah) × (12 V) × (3600 s) = 2,160,000 J
D34/D750S: (55 Ah) × (12 V) × (3600 s) = 2,376,000 J
TF: (110 Ah) × (12 V) × (3600 s) = 4,752,000 J
Raymond Tran -- 2002