{"id":551,"date":"2025-02-26T13:37:41","date_gmt":"2025-02-26T12:37:41","guid":{"rendered":"https:\/\/dev-site.se\/sutars.com\/?page_id=551"},"modified":"2026-05-21T10:01:06","modified_gmt":"2026-05-21T08:01:06","slug":"energy-balance","status":"publish","type":"page","link":"https:\/\/sutars.com\/en\/wired-inspired\/energy-balance\/","title":{"rendered":"Energy balance"},"content":{"rendered":"\t\t
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Energy balance<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Home<\/a> \/<\/span> Page<\/span><\/div>\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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How does energy balance work in practice?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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The table below shows examples of what common appliances on board a family boat consume over a 24-hour period.<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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The charging in the example assumes good charge acceptance, for example two to three 75 Ah service batteries (if they are fairly new, otherwise more) and well-dimensioned connections and cables in good condition.<\/p>

With a healthy electrical system, you can be self-sufficient with one hour of running per day, even without shore power, solar panels and wind generators.<\/p>

If you want a relaxing holiday, it is important that you learn your energy balance, since it varies from family to family how consumption is prioritized.<\/p>

We recommend installing a solar panel to always top-charge your batteries. A good solar panel could in theory power a newer refrigerator entirely on its own, which means less consumption to recharge.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Overview of Charging and Consumption<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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A 50 A alternator provides about 45 Ah in one hour of operation if the batteries are discharged and there are many of them. Otherwise, less.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Charging: 45 Ah<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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A 25 W solar panel can provide about 2 A when it is sunny. During the summer, you can get around five hours at that output. In cloudy weather, the output is naturally reduced.
5 \u00d7 2 = 10 Ah<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Charging: 10 Ah<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Total<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Total 55 Ah per day<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Consumption of electricity<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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NASA Marine\u2019s monitoring instrument draws a maximum of 5 mA. Over a 24-hour period, this becomes
0.005 A \u00d7 24 hours = 0.1 Ah<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Consumption: 0.1 Ah<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Four LED lamps with a total of 10 W that are on for 4 hours.
10 W \u00d7 4 hours = 0.04 kWh = 3.3 Ah<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Consumption: 3.3 Ah<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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A refrigerator with a compressor that draws 4 A but normally only runs 25% of the time, i.e. 6 hours per day.
6 hours \u00d7 4 A = 24 Ah<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Consumption: 24 Ah<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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