Technical B2B and smart alternator

[Major mike]

Hi, can someone tell me if my 2021 Fiat Ducato (Autotrail v line 635 sport )140bhp, with start /stop technology has a smart alternator as I would like to fit a B2B to charge the leisure battery?

I've been told by my local garage that fitting a b2b will require the resetting of the alternator?

Additionally is the leisure battery chassis earthed or insulated return?
Thanks
Michael

 

[NeilDD]

As you have start/stop then it will be a smart alternator.
A B2B charger should be configurable to work with the alternator and your leisure battery

The habitation 12V system should be chassis tied on the neg side

 

[Reg 65]

Yes - it will have a smart alternator (my Ducato is the same)
To check it you need a meter you can see when you are driving like this link
because it doesn't normally charge fully until you take your foot off the throttle and the momentum of the vehicle is turning the engine.
So the old method of checking the alternator (revving the engine when stationary) will lead you to conclude the alternator is faulty when there is nothing wrong with it.

Can't help you with the B2B because I have never owned one - with my self builds I just connect all the batteries in parallel with the main battery so they all get the benefit of regenerative braking to charge them, and there is no power lost in the B2B I carry a jump start battery in case something gets left on draining all the batteries.
Alternatively connect the batteries together through a relay that disconnects when the engine is not running so you can't flatten the main battery. Been using this method for 15 years, never needed to touch the alternator (smart or normal) and still working well. But since most motorhomes only have space for a small leisure battery and its a long way from the main battery you will need a B2B.

 

[Communicator]

As you have start/stop then it will be a smart alternator.
A B2B charger should be configurable to work with the alternator and your leisure battery

The habitation 12V system should be chassis tied on the neg side

In clarification the habitation system will normally use a wired return, but as stated it must be connected to the chassis, or starter battery negative This connection is necessary to complete the circuit for the alternator charging the habitation battery.