I am designing a solar system for use in Haiti to power 5-6 light bulbs. I am going to be using a marine battery for the storage unit. I know the general watt-hour rating of a marine battery is 1000-1200 watt-hours but I need specific numbers. I already know Ohms law and power formulas. I know the cold cranking amps (cca) and it is a 12V battery.
The battery is 690 cold cranking amps at 0 degees farinhiet. I know the formulas on Ohms law but how do you get watt-hours from cold cranking amps? This is the only ampere marking on the 12V car battery.
1000-1200 watt-hours is pretty specific, how much more do you need? Look at the specs of the battery you will be using. It may be speced in amp hours, just multiply by 12 to get watt-hours.
Take the lower number, 1000 watt-hour, and that means you can operate a 100 watt bulb for 10 hours.