Thanks for your input and sorry to interrupt your sleep (<:
To answer your question, I didn''t buy the Gel Cells or the charging system, the previous owner did, so I guess it''s shame on him. The boat has 4 105Ah batteries in 2 banks. Before repowering last year (another story) I had a 100amp alternator with Heart 3 stage regulation. My new Yanmar came with a Hitachi 80amp alternator and built in regulation. I certainly could simplify the wiring buy pulling out the now useless Heart unit. I''m on a mooring and don''t have any other charging capabilities.
Since I already have it, is the 3 stage regulator worth using, regardless of the type of batteries ? The auto/electric shop tells me my alternator can be modified for an external regulator for about $100.
To cut to the chase, correct me if I''m wrong, but it sounds like your advice would be to let the gel cells charge at the higher voltage and when they need replacing do so with lead acid batteries. The best part of this option is it won''t cost anything (time or $).