Newb Regulator under 4WD bonnet question

[Jman]

I have a Victron mppt 75/15 unit & wan't to install it in my 4WD engine bay so when stationary I can charge my auxiliary battery with portable external solar panel.
The auxiliary is part of a standard dual battery isolator setup & to connect the panel I will just have an anderson plug on bullbar. I will wire the regulator to the auxiliary terminals.
The isolator won't allow current to flow back to starter battery this way, so to it only charges the auxiliary as far as I know.

What I wan't to know is, while driving does the current coming from alternator & into isolator to auxiliary battery go back into the
regulator & cause damage? I have read how battery current can't flow back into the regulator, but the alternator has a higher voltage of around 14.2V
just wanted to ask as I have no idea really.

thanks

[Suprasoup]

Youll be fine. The Victron wont be damaged by the alternators input. I use a similar setup. Dual battery with a Blue Sea ACR. The auxiliary battery is hooked to a Morningstar Sunsaver 10. The Blue Sea uses dual voltage sensing relays so if either battery exceeds 13.6v (charging) it combines the two. Convenient as the alternator and the solar system can charge both batteries simultaneously. My solar is permanently hooked and I havent had any issues with it.

Try to locate the controller in a cool dry place. Underhood temps can exceed the operating temp of the controller. Heat and electronics dont mix well.

[Jman]

Youll be fine. The Victron wont be damaged by the alternators input. I use a similar setup. Dual battery with a Blue Sea ACR. The auxiliary battery is hooked to a Morningstar Sunsaver 10. The Blue Sea uses dual voltage sensing relays so if either battery exceeds 13.6v (charging) it combines the two. Convenient as the alternator and the solar system can charge both batteries simultaneously. My solar is permanently hooked and I havent had any issues with it.

Try to locate the controller in a cool dry place. Underhood temps can exceed the operating temp of the controller. Heat and electronics dont mix well.

Thanks good to know. I will place behind left headlamp near fuse box as its got space & pretty cool there.