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How to DETERMINE CAPACITY LOSS of boat batteries 🤓 | Ask The Expert with NIGEL CALDER
August 9, 2025 · 2 min · 1K views
What this video covers
Jan Attenstedt and Nigel Calder outline methods for identifying capacity loss in lead-acid battery banks.▶ 0:05 Monitoring amp-hours in and out via a systems monitor provides a baseline for comparing current voltage levels against historical performance at specific discharge states.▶ 0:55 For a definitive assessment, perform a controlled discharge test by fully charging the battery and then draining it until the voltage reaches 10.5 volts.▶ 1:02 Maintain a discharge rate between 5% and 10% of the battery's rated amp-hour capacity to ensure accurate results.▶ 1:37 Avoid discharging lead-acid batteries to zero volts, as this causes permanent damage.▶ 1:25 While this test stresses the battery, it serves as a necessary diagnostic step before embarking on a long cruise to verify that the bank can meet power demands.▶ 1:38 Lithium-ion batteries generally maintain consistent capacity over their life cycles, making this testing procedure primarily relevant for lead-acid systems.▶ 0:28
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