Sizing a battery bank. Ah VS wh?
Hi again! So, I'm trying to size out the battery bank I will need for my husband and I to live off grid in a camper. We don't have tons of time or money, so that's a bit of a factor. We plan on usi...
Forum Discussion
theoldwizard1 wrote:
For example, you want bacon and eggs with toast and coffee for breakfast. Easiest thing to use is an electric frying pan. Is you inverter up to the task of running the frying pan, toaster and coffee pot at the same time ? Throw in a hair dryer and few inverters could handle that.
Your average 30amp trailer on shore power isn't up to that...so it's a bit unrealistic. Even with a 50amp rig, you are going to have to be careful to keep those on separate circuits or you will be popping the breakers.
As far as amp-hr vs watt-hr...watt-hr is the more correct way to do it but as long as you keep the voltage the same, you can shortcut to using amp-hr (ie: you are generating, storing and using 12v all the way through, amp-hr works fine).
The problem with amp-hr is once you add an inverter, the voltage is changing (also DC vs AC). By going to watt-hr, it really doesn't matter (at least not enough to worry about).
Then it's a good idea to oversize by 10-30% because the system isn't going to be 100% efficient. Also, technically, 12v is not not exactly 12v. Depending on battery type and state of charge, it will vary a little from 12v but if you oversize a bit, that shouldn't be an issue.
