Wiggo
regular
Reged: 10/09/2003
Posts: 3467
Loc: (State, Country, etc.)
|
Re: How long should my domestic battery bank last ?
23/06/2008 18:22
|
|
|
Never been afraid to call a spade a manually operated excavating appliance...
If you really want to know if they're OK, get a £5 'turkey baster' hygrometer from Halfrauds and test them yourself. It only takes a few minutes.
What you need to do is work out how much current everything draws. A fridge can draw about 4 or 5 amps when it's running, but it might only be on 20-25% of the time, so it averages about an amp. If you know the power consumption, just divide by 12 to get the number of amps something needs, so your 10W halogen lights use just under an amp.
Now work out the energy use: just multiply the current by the number of hours you will run it. Fridge for 5 hours = 5Ah, two lights for 1 hour = 2Ah etc and that will tell you how long your battery should last. Bear in mind that you will rarely be able to use more than 40% of your batteries' stated capacity, so if you have 100Ah of domestics, expect to be able to use 40Ah or 40 hours of fridge and nothing else.
Incidentally, fridges are difficult to work out, because they use more power if you keep opening them to take beer out...
--------------------
The nicest thing about not planning is that failure comes as a complete surprise, and is not preceded by a period of worry and doubt.
Nereid Charter
|
|
Previous
Index
Next
Flat
Edit
Reply
Quote
