10-19-2022, 11:06 PM
@kaptain / Joe - That's a great schematic/photos.
I've probably read this too quickly or misunderstood something; however, what would be the reason not to simply go with a VSR (Voltage Sensitive Relay/Solenoid).
In other words, the alternator is direct-wired to the chassis-batteries; no Isolator/extra diode inbetween. Then, upon voltage reaching a suitable level, the solenoid connects the house batteries.
The level is typically one that must exceed a 12v battery output (eg 13.8v), indicating the alternator is effectively outputting current without substantial drain. As long as the alternator is running, the higher voltage automatically directs it to where it's most needed; you don't have an issue where an isolator is required in that situation because the alternator is always the highest-voltage source.
If you had different chemistries (eg LiFePO4 for the house batteries), this wouldn't be ideal; you'd be better off isolating with a DC-to-DC charger to gain some additional intelligence/logic; however, with SLA/AGM on both sides, I don't understand the benefit to a traditional isolator over the easier/less-expensive voltage-sensing switch.
I suspect I'm missing something obvious, but I felt it couldn't hurt mentioning on the off chance it inspired any new approaches
I've probably read this too quickly or misunderstood something; however, what would be the reason not to simply go with a VSR (Voltage Sensitive Relay/Solenoid).
In other words, the alternator is direct-wired to the chassis-batteries; no Isolator/extra diode inbetween. Then, upon voltage reaching a suitable level, the solenoid connects the house batteries.
The level is typically one that must exceed a 12v battery output (eg 13.8v), indicating the alternator is effectively outputting current without substantial drain. As long as the alternator is running, the higher voltage automatically directs it to where it's most needed; you don't have an issue where an isolator is required in that situation because the alternator is always the highest-voltage source.
If you had different chemistries (eg LiFePO4 for the house batteries), this wouldn't be ideal; you'd be better off isolating with a DC-to-DC charger to gain some additional intelligence/logic; however, with SLA/AGM on both sides, I don't understand the benefit to a traditional isolator over the easier/less-expensive voltage-sensing switch.
I suspect I'm missing something obvious, but I felt it couldn't hurt mentioning on the off chance it inspired any new approaches