What am I looking at here (Dual Battery setup)

[Flo-w]

I'm in the process of "getting to know her" and I took a closer look at the dual battery setup today. What do I see in this picture? Is that an isolator?

[Clunk]

it is yes, or some call it a solenoid................ would have a clue how it works though but with any luck one of our learned elektrickery gurus can shed some light

[Yendor]

Yes it can be used as a dual battery isolator, depends on how it is wired up.

It basically a heavy duty relay. If you supply power and negative to the smaller terminals, a plunger will move within the solenoid joining the two larger terminals together.

[Flo-w]

I'm wondering if I should replace it with a real charger like the CTEK D250S which I had in my last setup. Should make better use of the second battery in terms of life expectancy and Ah I get out of it.

[happygu]

The Ctek or similar units are a much more sophisticated way of charging and monitoring the auxiliary battery, as it will do things like load sensing, and will decide when the best time to charge the battery is, and by how much.

A heavy duty solenoid like yours can be effective, but it is either on or off, so they tend to shorten the life of an auxiliary battery a little more. That is not to say that there aren't many people running this type of setup successfully

Mic

[Flo-w]

I think I'll keep it simple for now and just keep what I already have as long as it works.
Thanks everyone for your replies.