Sorry guys, need your help again. I've read some books, now trying to practice my understanding of batteries. Could you please verify my calculation below? Nothing is real, purely trying to work out the formula:
If I want to calculate how much battery do I need for overnight staying on a boat, suppose I don't run generator, one "night" I mean 12 hrs(some of the numbers are rounded):
One Refrigerator: 150w x 12hr = 1.8kwh per night(the 150w number I found on line, average)
One Freezer: 100w x 12hr = 1.2kwh per night
Ten Bilge pumps(assume they runs twice an hour, for 5 minutes per time): 100w x 10 x 24 x 5mins / 60mins = 2kwh per night
One Air conditioner(assume it runs continuously): 900w x 12hr = 11kwh
So in total I need: 1.8+1.2+2+11=16kwh
If I buy battery rated 300ah, I need: 16000wh / 12v / 300ah = 4.5
So I need to install at least 5 batteries(again, not counting discharge rate, 50% reserve etc).
If I want to calculate how much battery do I need for overnight staying on a boat, suppose I don't run generator, one "night" I mean 12 hrs(some of the numbers are rounded):
One Refrigerator: 150w x 12hr = 1.8kwh per night(the 150w number I found on line, average)
One Freezer: 100w x 12hr = 1.2kwh per night
Ten Bilge pumps(assume they runs twice an hour, for 5 minutes per time): 100w x 10 x 24 x 5mins / 60mins = 2kwh per night
One Air conditioner(assume it runs continuously): 900w x 12hr = 11kwh
So in total I need: 1.8+1.2+2+11=16kwh
If I buy battery rated 300ah, I need: 16000wh / 12v / 300ah = 4.5
So I need to install at least 5 batteries(again, not counting discharge rate, 50% reserve etc).