BoatHowTo · video

What this video covers

Nigel Calder advises that standard automotive battery testers fail to accurately assess marine house batteries because they are designed for cranking duty cycles rather than deep-cycle discharge.0:48 To determine the true health of a house battery, perform a full capacity test by first charging the battery to 100%, then discharging it at a controlled rate while measuring the time taken to reach a specific voltage.1:16 If the remaining capacity falls below 80%, the battery is likely nearing the end of its service life.1:40 Calder recommends conducting this test every two years and emphasizes testing even brand-new batteries, as they may have suffered from sulfation while sitting on a retailer's shelf for years.1:55 Retailers often rely on inaccurate, quick-read meters that do not reflect the actual capacity of deep-cycle units.2:53 Verifying the manufacturing date code before purchase helps avoid buying aged stock.2:15 A full capacity test provides the only reliable metric for determining if a battery bank can support a planned cruise.0:38

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