The answer to this is very simple, mathematically speaking. Our narrowboats have a battery bank of 28.6kWh of which we can use up to 80% on an infrequent basis and 50% on a regular basis. 22.8kWh or 14.3kWh respectively. Or narrowboats use 1kW to move along at cruising speed. The actual speed through the water depends on factors such as how shallow the canal is which will reduce speed, however in good water conditions using 1kWh you should expect to travel about three miles. Rounding up and just using 50% of the battery you therefore should expect to travel 42 miles.  However, because our boats have 2kW of solar on the roof, on a sunny day you can expect to generate 10kWh.  This means that to travel the 42 miles you’ve only used 4.3kWh and your battery will be at approximately 85% right State of Charge (SOC).