How to safely charge LITHIUM Batteries with the alternator | Renogy Charge Controller
October 10, 2024 · 6 min · 2K views
What this video covers
A lithium house bank with unequal cable lengths causes one battery to cycle between 95–100% while the others discharge to 80%, preventing the full bank from reaching a complete charge. Alex diagnoses the problem by logging into the SOK battery monitoring system, which shows each cell's individual state of charge.Watch The fix requires adding two bus bars adjacent to the starter battery and cutting all inter-battery jumper cables to the same length — matched to the longest run — so current distributes evenly across all cells. The 2-gauge wire donated by Ben from Sailboat Story cannot be used for the jumpers because of the length-matching requirement. The bus bar project is deferred while a more immediate installation proceeds: a Renogy charge controller mounted in the battery compartment that accepts both alternator and solar inputs, charges the starter battery first, then diverts surplus to the lithium house bank. Drilling the mount requires a 90-degree drill attachment to reach the confined space. Equal cable length to a common bus bar is the critical factor in balancing charge and discharge across a parallel lithium battery bank.0:10
More from Wildly Intrepid Sailing
From Wildly Intrepid Sailing — see the channel’s boat, crew, and every analyzed video.
The Sailing Directory Newsletter
One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.