Dual Battery Set-Up

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keeper

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SoCal
I am preparing to start a dual battery set-up. After days/weeks of research and debate of ACR (Automatic Charging Relay) vs DC-to-DC I have settled on the Ctek Dc-to-dc system. My eyes are a little watery and brain a little mushy from all the information out there so I wanted to post my plan and get some opinions from the pros (that would be you guys). Here is what I am planning. What are your thoughts? The 300A fuses seem like a lot but that is what the manual says.

DC-to-DC.jpg

Cable_and_Fuse.jpg
 
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Enthusiast III

I am 100% not an expert on these systems, but I'm eager to hear what others say and appreciate you putting this out there -- I'm just learning for my own build. If I'm understanding the diagram correctly, I don't see anything that immediately jumps out as contrary to what I know -- but again, what I know is that batteries make lights go bright using witchcraft and plastic hoses full of metal (OK, I know a bit more than that, but not nearly as many other gurus here know). The fuses look like they are in the right spots as far as I can tell, though depending on accessories the 300 amps might be higher than I'd be comfortable with. As far as I know, the purpose of those fuses are that if there's a short anywhere, that fuse will blow before a fire starts, so I would size that fuse according to load where possible. My thinking is that I'd rather replace a big fuse 10 times for no reason, than have too big a fuse cause a fire. Obviously there is a balance somewhere, I just don't know where it would be in your application.

I have some questions but they are based in my ignorance, not in any shortcomings I see in your design, and I tend to learn a lot from discussion so I'm hoping you don't mind me picking your brain a bit!

I'm guessing I will answer my own question here, but it looks like you have a CTEK charger for "Shore Power", you have the DC to DC for Solar, and then another unit (Smartpass) to go from Starter to House. I've been under the impression that the DC to DC is all you need to go from Starter to House. Therefore, my question is -- what purpose does the Smartpass serve in this application? Is it because the DC to DC can only have one "input" and that's Solar? Is it not OK to go from Starter & Solar - DC to DC - House Battery - Fuse Panel - Equipment?

Do you plan on having a winch hookup, and if yes, are you going to wire that to your House Battery or your Main Battery? I'm thinking of doing a main battery for my winch, because my house battery will be in the bed of the truck and I don't want a long run of heavy gauge wire to go to the front -- it's a lot of extra wiring weight.

And that prompts my next question. Is there a way for your to mount your batteries and charging system closer together? You've got it spec'd for 14' of pretty heavy gauge wire, and while the heavy gauge is necessary, that's an extra 20-30 lbs (Maybe, I'm not sure how much your particular wire will weigh) that you might not need if you can geographically move them closer.

At any rate, thanks for posting this and for the inevitable information that will hopefully flow from this thread!
 

keeper

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Contributor I

60
SoCal
The Smart Pass allows the system to help jump the start battery, boost the charging volts to 14.7 for AGM batteries, and increases the amps to 140A for a quicker charge when needed.

I am afraid I am very tight in space under the hood so I am going as close as I can along the frame rail.
 
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Enthusiast III

The Smart Pass allows the system to help jump the start battery, boost the charging volts to 14.7 for AGM batteries, and increases the amps to 140A for a quicker charge when needed.

I am afraid I am very tight in space under the hood so I am going as close as I can along the frame rail.
That makes perfect sense, that little device adds a lot of options. I may look at adding one to my build now too. Thank you for answering that!

Totally understood on the space limitations. You gotta make due with what you can.

Thanks again for answering my questions -- hopefully the traffic gets it on more people's feed so you get more experienced answers to your post too!
 

Farmjeepwrangler

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1/0 wire is too small for 300 amp fuse (wire would get hot). Best use 150 amp breaker. The only device that would call for 150amps is a 1000/1800 max watt inverter.
 

Magic Mike

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After a lot of research on the CTEK DS250 and the Redarc, I decided on the Redarc BCDC 1225. Each of these units are good options, but in the end the for me the Redarc had a cleaner install and a smaller foot print. Open real estate under the hood of a 5th Gen 4Runner is a premium and all the wires sitting exposed on top of the CTEK makes me nervous. Although I wish the Redarc came with a battery monitor like the CTEK, but oh well.

The Redarc was a pretty simple and straight forward install and is working great. It is set to charge at 14.6 volts and can be changed based on the type of battery that is being used.

Getting ready to add a 100 watt solar panel..

IMG_1401.jpgIMG_1420.jpgIMG_1421.jpgIMG_1422.jpg
 
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