Could someone please advise me here?
I have set up 12/12-18 DC-DC charger in a boat, as shown in attached first photo. I'm using battery isolator, to ensure that I do not charge Service battery from the Starter battery.
Engine's start current is 250A and it starts normally with 2 secs. Starter battery is 77Ah Lead Acid, so the charging current of starter battery should be around 19A (25% of capacity). Therefore I estimated that it would take around 20...30 sec to full charge starting battery after starting the engine.
I had tried different "Delayed start voltage" (13.8V, 13.9V, 14V) and different "Start voltage" (14V, 14.1V), but still charging of the Service battery starts very quickly- within 2....5 seconds.
May be somebody could give me a hint- which settings/values to use in Orion set up for delayed start?
The reason why I wish to have delayed start:
when I charge both batteries at the same time, then total charging current from alternator is about 40A and I'm wondering if this could burn up the alternator?
The alternator is 60A, Hitachi LR160-741, that generates only 25-35A at idle at low RPM (1500...2000). Alternator's characteristics:https://www.manualslib.com/manual/825607/Yanmar-3ym30.html?page=206&fbclid=IwAR07sVdwhNENhgF4O7F3s0Nu6ELvCxN_KlTzMcJEjv_O_o4GsgIIxWn5Wog#manual