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...
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Use one or the other. I prefer watt-hours.
If planning on using an inverter for everything (which is not recommended), forget about 12 volt and jump to 48 volts. Why? Because the inverter may be a lot more efficient at 48 volts compared to 12 volts. Cabling between the battery bank will be far cheaper.
If you are stationary, and have a beer budget, use six volt golf cart batteries. Lead acid batteries do want to be fully charged as often as humanly possible. They needs must be equalized at least every 30 days, and once a week would be a better time frame.
To find the solar wattage needed go to a site that lists the solar insulation hours for your location. If that is too much trouble--then divide the watt-hours used in a day by 5 (example 2200 / 5 = 440 watts of panels).
For full time off grid the battery bank size ought to reflect at least 3 days of no sun.
If you are mobile and do not plan on cold weather use, go to 24 volt lifepo4 batteries with 2 in series. Or better yet, "roll your own". It will be needful to have a proper battery management system. Li are great, but they are UNFORGIVING. They can be seriously damaged or destroyed by just one seeming small error on your part (the human factor).
A back up generator will be needful. It needs to be large enough to meet the daily requirements AND recharge the battery bank.
If planning on using an inverter for everything (which is not recommended), forget about 12 volt and jump to 48 volts. Why? Because the inverter may be a lot more efficient at 48 volts compared to 12 volts. Cabling between the battery bank will be far cheaper.
If you are stationary, and have a beer budget, use six volt golf cart batteries. Lead acid batteries do want to be fully charged as often as humanly possible. They needs must be equalized at least every 30 days, and once a week would be a better time frame.
To find the solar wattage needed go to a site that lists the solar insulation hours for your location. If that is too much trouble--then divide the watt-hours used in a day by 5 (example 2200 / 5 = 440 watts of panels).
For full time off grid the battery bank size ought to reflect at least 3 days of no sun.
If you are mobile and do not plan on cold weather use, go to 24 volt lifepo4 batteries with 2 in series. Or better yet, "roll your own". It will be needful to have a proper battery management system. Li are great, but they are UNFORGIVING. They can be seriously damaged or destroyed by just one seeming small error on your part (the human factor).
A back up generator will be needful. It needs to be large enough to meet the daily requirements AND recharge the battery bank.
