The On Deck Channelvideo
Lithium On Your Boat (Check Your Settings) | CLIPS
March 20, 2026 · 4 min · 551 views
What this video covers
Lithium batteries from some Chinese manufacturers include a hidden "full charge protection" feature — a firmware-level cutoff that stops charging at a fixed voltage, often 14 V, without disclosing this in documentation.1:14 Steven explains that this cutoff is enforced through charging MOSFETs and is invisible until the system hits it.1:37 When an alternator charges a large lithium bank and strikes that hidden wall, the sudden current rejection causes a voltage spike that can damage onboard equipment.2:41 The fix is to set the alternator's charge voltage below that threshold — around 13.9–13.95 V — so the cutoff is never triggered.2:53 Steven also warns against floating lithium batteries above 14 V for extended periods, which accelerates dendrite formation and shortens battery life.3:53 The correct lithium charge profile climbs to roughly 14.2 V, then drops to a float of 13.5–13.6 V, the battery's resting voltage.4:02 The absolute maximum for lithium is 14.6 V, but staying near that ceiling degrades cells faster.3:14 North American importers who rebrand Chinese cells — such as early Epic batteries — are more likely to have identified and corrected these hidden protections through software updates; direct-import brands may not have.1:57
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