BoatHowTo · video

What this video covers

A viewer asks whether a 5-watt solar panel is sufficient to maintain batteries on a moored boat with no shore power, and whether a voltage regulator is needed.0:28 Nigel Calder confirms the 5-watt panel is too small for any but the smallest battery bank and states that running a panel without a voltage regulator risks overcharging and expensive battery damage.0:49 He notes his book contains a formula for the maximum safe wattage per 100 amp-hours of battery capacity without a regulator, but the threshold is low enough that a regulator is effectively always required.1:00 A quality MPPT charge controller costs well under $100 for low-output applications.1:22 Calder and Jan Attenstedt recommend stepping up to a 30–40 watt panel paired with a small MPPT controller as a practical minimum for mooring maintenance.1:55 Jan notes his own boat carries a 45-watt panel that keeps batteries charged during extended periods on a mooring.2:02 The cost of a proper panel and MPPT controller is recoverable against premature battery replacement caused by chronic under- or overcharging.1:34

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