Dual DC DC Chargers ..

[gavchiefster]

I am looking for a dcdc charger..
I HAVE an MQ TRITON in Australia with a NON variable alternator around 90amps.
It will have a 200amp lithium battery and one ,160 w solar panel at 10amps output. 22volts
am running an aluminum canopy which will run a fridge and LEDs and inverter etc.
I have a camper trailer with a 120amp AGM in a tool box on the draw bar. I will run a second fridge/freezer in the camper and a few more LEDs and charging phones and other 12v gear.
I have Thick heavy gauge wiring at the Anderson plug on the drawbar approx 13-16mm2 cable..
*NOTE* I DONT currently have cable run from car starter battery to tow bar yet as I'm not sure if I can use one or 2 dcdc chargers or have to run one charger and rely on solar for the camper.

I was looking at the CTEK 250SE at around $360 au yet I don't really want the extra expense of the smart pass at another $350-400 just to pump the amps up for charging on the move.
I'm more steering towards the renogy 60amp or the enerdrive 40amp dc DC charger.
The bigger dilemma what I cannot find anywhere is can I run ONE dcdc CHARGER with a higher output to charger both batteries, both the camper trailer appliances for power charging the AGM and also use the same dcdc to run the lithium in the Ute for other fridge and inverter. ??
Maybe I would have to run sperate dcdc chargers for this purpose?
My trailer is a soft top so I cannot run a hard wired solar panel ontop I can only run one ,160,w panel on the car/ Ute roof or maybe be able to fit one bigger 240w house solar panel ..

Any advise to run both Ute set up and a camper trailer set would be welcomed to decide on what dcdc charger i need in if I need 2 chargers??

 

[SamDeleted]

Maybe I'm wrong here, but don't you just need a split charge relay ?

 

[mikefitz]

The alternator at 90 amps does not leave a great deal of power available for auxiliary charging. At engine idle the output will be no more than 70 amps and the vehicle could need 30 to 50 amps for system electronics, lights, air con and so on.
A DC to DC at say 40 amps will pull 45 to 50 amps from the engine charging system resulting in a possible overload on the alternator.

If I understand correctly engine charging will be needed for a 200 Ah lithium in the truck and a trailer with a 120Ah AGM, with, I guess, the requirement to power the trailer when parked up with additional power from the truck lithium. In adition there will be solar charging for the 200 Ah battery.

I would have this setup:
A separate MPPT solar charger for the solar charging the lithium battery, this will give freedom of using any panel voltage.
A DC to DC charger from starter battery to truck house lithium battery, perhaps 30 or 40 amp unit.

For the trailer use the connector to put the AGM in parallel with the 200Ah lithium. This will alow a partial charge to the AGM, and allow the lithium to power the trailer circuits. From time to time charge the AGM on its own with a correct AGM charge profile.

Future modification could be replacing the AGM with a 50Ah lithium.

Mike

 

[pollenface]

I have two dc-dc chargers in my patrol, one for each aux battery as they are slightly different (agm & marine).

I also have a solar and additional mppt on the agm so it's always pretty much in float and it's dc-dc charger hardly ever comes on.