DC to DC charging?

[Jay & Bobbie]

I am wanting to install a DC to DC charger. I know there has been a lot of discussion and information on the subject. There are a couple concerns/questions about my specific install.
1. I am looking at the Renogy 40w charger. My truck has a single alternator that I think will handle it. Will a 40w charger keep the battery charged while traveling? The only significant draw on the road is the Samsung residential refrigerator.
2. The cost of wire. Solid copper wire (#2) is crazy. Can I use copper coated aluminum wire?
I think I have a good idea about the other stuff; circuit breakers, Anderson connector, etc.
Thanks in advance for all responses.

[AZ Traveler]

Jay,

Please tell us a little more and you will get better recommendations.

I assume you are looking at a 40 amp vs watt charger.

What is the size and type of your battery bank? Unless you have lithium batteries you may not be able to handle 40 amps.

Do you have any solar?

If you are only worried about powering your reefer the 7 amps you currently get off the standard plug will work pretty well. It will also stay cold for several hours if you turn it off and don't open the doors.

[Daryles]

Here's a link to my installation write up.
Hope this helps.

https://www.montanaowners.com/forums...hlight=charger

[LeftOverParts]

Assuming your batteries can handle it, you can look online for a wire size chart by volts, amps, and feet. (Some sites will include line loss). Wire can be welder’s wire (has fine strands and is flexible).

For a just a fridge, you could go down to a 20A charger which would allow smaller gage wire and lower corresponding costs. Depends if you want to grow your system later.

You might want to check your single alternator capacity to see what it can handle.

[77cruiser]

I used this wire for my 18 amp charger.
https://www.amazon.com/dp/B000NV2ATU...roduct_details

[suny07]

Hi,

I am selling my DC to DC Charger, 40 amp:

https://www.montanaowners.com/forums...ad.php?t=90654

I think I also have the cable lying around to connect from the 5th wheel hitch towards the battery compartment.

Thanks,
Mike

[Jay & Bobbie]

More info:
I have no solar.
I have a renogy agm 200ah battery.
I have a renogy battery monitor that is set to 100ah so I know usage base on 100ah.
During a normal travel day, the battery will decrease about 25%.
I did mean 40 amp charger.
The id tag on mt alternator corresponds to a 150 amp output.
I would be fine with a 20amp, but like the price of Mike's 40.