How to install DC/DC charger on 2017 Hawk

[Karlton]

Hi all - like many, I replaced the old AGM batteries (thanks for a great 8 years, AMGs!) with a lithium ion battery. I installed the battery and was perplexed by the draw shown on the BVM. So, I consulted the forum and learned all about smart alternators, voltage differences, how the Blue Sea ARC works and why it isn't a good match with a LI battery. I really appreciate everyone's input on previous posts!

I've deducted that I should get a DC/DC charger to prevent the camper battery from providing power to the truck so that I can charge the camper battery from the truck alternator. Question is...

Does the DC/DC charger replace the Blue Sea ARC or does it go somewhere else in the wiring diagram? I have a 2017 Hawk front dinette with the standard wiring to the truck.

Thanks again, all!

 

[K7MDL]

I just upgraded my 2022 Front dinette.

External Li Battery Upgrade Install Concept

I have a 50Ah LiFePO4 battery and 50amp capable waterproof DC-DC converter with integrated solar charger today for my ham radio battery needs. I use them in the truck cab today, tapping off the 6GA cable run between the camper and the alternator so that the camper batteries can power my radio...

www.wanderthewest.com

The DC-DC Converter isolates the starting battery from the camper battery. Some charger models like mine will trickle charge the starting battery from solar if the camper battery is sufficiently charged.

You can bypass or remove the ACR. I left my ACR in place and simply moved both wires onto the same stud. My DC DC charger is located under the truck cab.

I ran new #6 wire from the charger into the camper, the thick red and black wires visible in the picture attached. The ACR is acting as a terminal stud leaving it for a future owner should they want it for some reason. The ACR could be removed and replaced with a standard terminal stud or you can land it on the truck side of the circuit breaker. The breaker is a small size stud and the ACR is 3/8" so I left the ACR.. I ran the solar panel positive through the old battery cable and into the old #10 harness white wire to the charger under the truck so it charges the camper and truck batteries. Putting the charger in the camper would make that simpler, make sure it has sufficient ventilation. My unit will get quite hot at load.

 

[Karlton]

Thanks for the reply K7MDL! I read through some of your replies to other treads and will check out what you provided.
Cheers

 

[Vic Harder]

i'd remove the ACR.

 

[K7MDL]

If I removed the ACR, I would replace it and the stock breaker with a 60A marine breaker that I can manually trip. I use one on the truck battery end. Then I can de-energize the camper plug.

 

[Karlton]

i'd remove the ACR.

Hey Vic - nice to see your reply. You've helped me out over the years. I think the product listed below is what I'm looking for. Do I need the 30 amp or will the 18 amp suffice. I should add I have 200 watts of solar.

Where I can use some help is how to sort out the input (+ -) and output (+ -) on the Victron compared to the Blue Sea. The positive side of the equation makes sense, just not sure where to connect the ground on the ARC to the Victron

Victron Energy Orion-Tr Smart DC to DC Charger (Bluetooth) - 12/12-Volt 30 amp 360-Watt - Battery Charger for Dual Battery Systems - Isolated​

 

[Karlton]

Following up on my post, I think I found the Victron product that is a better match for the wiring configuration of the Blue Sea having an In, Out, and Ground. I think I'm going with the product below to replace the ARC.

Victron Energy Orion XS Smart DC to DC Battery Charger 12/12 50A (700W) - IP65 Dust & Waterproof - Fully Configurable - Remote Management Possible - Advanced Battery Protection​

 

[Vic Harder]

That is a nicer unit. The 30W tends to run hot, the 50 does not. The ground that the ACR uses is a "reference" point I believe, not a current carrying wire. You do not need the isolated version.

And +1 to what K7MDL said replace the small thermal breaker with one that you can trip/disconnect. Do you have enough info now?

 

[Jon R]

The ground wire to the ACR is what provides power for the ACR’s control circuitry and the coil that pulls in the large relay connecting the two battery positives. It does carry current, but only to operate the ACR - about 1 amp. Without that ground all the ACR has is a 12v positive connection. If you disconnect that ground, you disable the ACR.

 

[kmcintyre]

I think you've got your answer, but most newer units have some type of "isolation" built in and only open up the currently flow when the engine is running.

 

[K7MDL]

Took my own advice and installed a 50A breaker with manual trip, replacing the stock breaker and ACR. Opening this breaker, a similar 60A one under the hood and pulling the solar panel fuse in old battery compartment in the back will totally depower everything.

I typically put a breaker or fuse closer to the battery then I have here, but the cable is in a protected area.

I have 1 more wire mod to make, I will put a SB50 connector near the battery so I can quickly and easily disconnect and remove it for winter storage. It will also let me quickly swap to my 50Ah Li battery. I normally use the 50Ah for my portable microwave radio gear. The connector will let me charge it up in the field, or can provide power when my 100Ah runs low and I do not want to run the truck engine or cannot plug into shore power.

 

[Karlton]

That is a nicer unit. The 30W tends to run hot, the 50 does not. The ground that the ACR uses is a "reference" point I believe, not a current carrying wire. You do not need the isolated version.

And +1 to what K7MDL said replace the small thermal breaker with one that you can trip/disconnect. Do you have enough info now?

Yes. This thread has been very helpful. Got the Victron Orion XS today and about to install.

 

[csasper]

We're doing the same thing as you. Could you post a photo when you're done?
Thanks!

 

[Jon R]

In sizing your wire from the truck to the dc to dc charger, recognize that the charger is going to draw from the truck about 15% more current than the rated output current to the battery. My Orion 12/12-30 draws about 35 amps. The XS50 is more efficient, but at full 50 amp output you still should be sizing fuses and wire for continuous 55 to 58 amps.