DC to DC to be placed alongside Victron 12-12-30A

[fiox89]

Hi everyone. I'm looking for a possibly economical way to increase the input current to my battery. I currently have a non-isolated Victron 12-12-30A, which delivers 30A perfectly while the motor is in idle. The alternator is 120A, so it should hold let's say a further 15/20A.

I had thought about installing an additional dc-dc 12-12-18A Victron, but it seems to only exist in an isolated variant. Can I install it anyway? better alternatives?

 

[mikefitz]

A 120 amp alternator is delivering around 80 amps at idle speed. When all vehicle 12 volt systems are loading the alternator, cooling fans, lights, perhaps 30 to 40 amps are needed.
The Victron Orion 12 12 30 is not very efficient, typically taking 35 amps from the alternator. It also runs hot and in many installations is delivering less than 30 amps, as it reduces power at higher temperatures.
You could add the 18 amp charger, again not very eficient, but the additional power needed may overload the alternator.

The best ( but expensive) option is to consider the Victron Orion XS, a 50 amp very efficient unit. It offers many more functions than the 30 amp unit including output current control. Thus could be set to a lower output current if required. This unit would replace the 12 12 30, (sell on ebay)

 

[fiox89]

A 120 amp alternator is delivering around 80 amps at idle speed. When all vehicle 12 volt systems are loading the alternator, cooling fans, lights, perhaps 30 to 40 amps are needed.
The Victron Orion 12 12 30 is not very efficient, typically taking 35 amps from the alternator. It also runs hot and in many installations is delivering less than 30 amps, as it reduces power at higher temperatures.
You could add the 18 amp charger, again not very eficient, but the additional power needed may overload the alternator.

The best ( but expensive) option is to consider the Victron Orion XS, a 50 amp very efficient unit. It offers many more functions than the 30 amp unit including output current control. Thus could be set to a lower output current if required. This unit would replace the 12 12 30, (sell on ebay)

Thanks mikefitz, I was definitely considering the new Victron XS but it doesn't look like it will get to me in time (Italy) and I'll be back living in the Van in 2 weeks, tight deadlines, otherwise I would consider it.

About the 12-12-18A I would have space problems with the cables, I was thinking, is it possible to use the GND of the first Victron 30A (non-isolated) and connect on the same line the Negative-Out and Negative-In of the 12-12-18A? basically bringing everything back to common Ground