BoatHowTo · video

What this video covers

Jan Attenstedt and Nigel Calder address the risks of using a 1-2-Both battery switch, specifically the danger of destroying an alternator by switching to "off" while the engine runs or accidentally draining the starter battery by leaving the switch in the "both" position.Watch To upgrade a system with a starter battery and an expanded house bank, Calder recommends replacing the 1-2-Both switch with two individual on-off switches.0:57 This configuration prevents accidental paralleling of batteries.0:57 For charging, he suggests wiring the alternator directly to the starter battery and using a voltage-sensitive relay or a battery-to-battery charger to manage the house bank.2:12 Shore power chargers should connect primarily to the house batteries, with a relay facilitating charging for the starter battery.2:21 These modifications modernize simple electrical systems found on older sailboats by automating battery isolation and charging distribution.

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