Energy balance
The table below shows examples of what ordinary appliances on board a family boat consume for a day.
The charging in the example requires good charging receptivity, for example two to three 75 Ah consumer batteries (if they are fairly new, otherwise you need more) and well-dimensioned connections and cables in good condition.
With a fresh electrical system, you can be self-sufficient with one hour of driving per day even without land power or wind turbines
If you want a calm holiday, it's important to learn you energy balance, since it varies from family to family how you prioritize your consumption.
We recommend installing a solar panel to always top charge your batteries. A good solar panel would in theory be able to provide a newer refrigerator all by itself, which means less consumption to charge with the engine.
Generating |
Description |
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|
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A 50 A generator generates approximately 45 Ah in one hours drive if your batteries are discharged. | 45 Ah | |
 Solar panel |
A 25 W solar panel can give about 2 A when it is sunny. During the summer you can get out about five hours with that effect. In case of cloudy weather, the effect of course is reduced. 5 x 2 = 10 Ah |
10 Ah | |
Total sum: |
55 Ah per 24 h |
Generator
Consumer |
Description |
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 Battery monitoring |
Nasa Marines monitoring instrument uses max 5 mA, on 24 h it draws: 0,005 A x 24 h = 0,1 Ah |
0,1 Ah | |
 Light |
Four led lights with a total of 10 W that shines in 4 h draws: 10 W x 4 h = 0,04 kWh = 3,3 Ah |
3,3 Ah | |
 Refrigerator |
Compressor refrigerators that uses 4 A, normally only works 25% of the day, on 24 h it draws: 6 h x 4 A = 24 Ah | 24 Ah | |
 Diesel heater |
|
5 Ah | |
 TV or computer |
A TV that is being used draws between 50 och 100 watt, ie between 4 and 8 A. So one hour viewing per day draws: 1 x 8 = 8 Ah |
8 Ah | |
 Pumps |
Pumps for fresh water and bilge pump usually draw about 1 Ah per day together. | 1 Ah | |
|
Total sum |
41,4 Ah per 24 hour |