Dual Battery Setup (1 Viewer)

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I added another 35 AH of battery to the system today- tied to the house battery via the RigRunner, for now. This little U1 will sit behind the fridge. Duracell sealed AGM deep cycle.

This will bring the total house battery system up to 100AH.

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Yellow APP is my new extension cord outlet for Micro USB charging and USB Charging.

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Hey @weejub, cool thread and really nice setup!

I'm installing the exact same in my car. I had it up and running, but took it down again to reposition the batteries. Right now I'm just browsing and I saw your setup. You didn't connect your batteries directly to the VSR as Bluesea shows. Is there a reason to that?
 
Hi @Frkens - Thanks!!

Several of us want our starter battery to handle all of the "normal" duties and to simply isolate the house battery except for charging.

As such, I used @Cruiserdrew 's feedback and connected to use the ACR as strictly a level between the house battery and starter battery. Wanted the starter battery to basically always be "on" like normal on the starter, then turn the second battery off via the switch and then combine both batteries manually.
 
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@weejub Aah I see. That makes sense, thanks a lot for explaining it. I'm getting smarter by the minute being on Ih8mud :)

Actually I have a question that you might be able to help me with. The bluesea instructions tells me to connect my circuit breaker to the starter of the car as you can see in the drawing below. Why not just connect it to the starter battery instead??

Schematic.jpg
 
I'm not seeing the circuit breaker - Do you mean the switch on the starter?

That looks like an RV set-up where you have a big inverter with a huge demand and multiple independent circuits.

I don't think you would want to run all those additional lines to isolate an inverter when you could just combine the house and inverter battery for more amp hours. You are basically looking at increasing your costs by 100%+ with that system with the Duo Charge and the Solenoid plus all the extra cable and fuses etc.

I am pretty new to this, myself. If you are doing a RV or something, then you may want to seek someone with more experience :)
 
Yeah I uploaded a bad file. I used this for inspiration, this is not my setup, don't worry!!

This is more similar to my setup and from the bluesea manual. I don't understand why they are so particular with connecting the circuit breaker to the starter (as marked with red). Why not just connect it to the alternator? Is it because it's simpler to connect it to the starter?

Wiring VSR with starter.png
 
The section in red would be if you wanted to separately run a new line from your alternator vs using your factory line. So #2, for example, would mean simply the alternator and switch both go to the switch position 2 in the upper right corner of the switch as it is shown on the bigger diagram. Option 3 would be what we have done effectively, but through the switch.

I think your real question is why does Blue Sea recommend the engine/alternator lines go through the switch vs straight on to the battery and then to the switch like we have done.

That design was to simply maintain a factory starter/alternator set up for switch position 2 - so "OFF" would ONLY impact the house battery and not both batteries. They are doing this for a boat where people put them in storage and want both batteries turned off.

The set up provided by @Cruiserdrew and with input from others allows you to basically be "on" with the ACR having both batteries in relay, or "off" where the 2nd battery is turned off, or "combined" where both batteries are working together.
 
@weejub thanks for your response, but I feel like I don't get it totally yet. I'm sorry but I have a couple of new questions.

1. Why would I want to add a new line from my alternator? And to what?
2. Alternator and switch (which switch?) goes to circuit breaker in upper right corner. I cannot see any switch besides from the circuit breaker.
3. No I understand why Bluesea would recommend a line from the alternator to the circuit breaker and on to the battery. But I do not understand why they recommend doing it from the starter.


Below I drew a schematic of how I understand Bluesea's recommendation. I don't understand it at all, so I'm sure that I am misunderstanding something!

My baseline for this drawing is that the circuit breaker can be used to switch between two conditions.
C1. Normal: Car battery is low and cannot start the car
C2. Emergency start: The extra batteries are connected to the car battery and can therebby assist on starting the car.

4. If I wire my system this way, I will be able to start my car only because there is a seperate line from the car battery to the starter. But if there is a permanent line between those, why is it then relevant to havea line between them through the circuit breaker too?

I'm lost here man, sorry about the bombardment of questions, hope you can help.

Unavngivet.png
 
@Frkens

No worries - very confusing stuff!

Short version:

Lets cut to the chase: If you are using the Blue Sea ACR/Switch combo, then just do the below. Unless you have specific needs that are not met, you should ignore the Blue Sea diagrams. Connect your truck's positive line to your #1 battery positive and your truck's ground/negative to your #1 battery negative. Done. "ON" gives you both batteries through the ACR. "Off" turns off your 2nd Battery and house electronics. "Combine" combines both batteries for emergency starts, etc. The below diagram does it all well.


IMG_0513.JPG




Long Version:

I will address your above questions:

1. Some people choose to run a new wire with larger gauge, etc. They feel this is a "clean up" measure to use new copper, etc. You would really need the same size wiring for your negative, as well if you do that. I don't think you want to do that.

2. This thing here is called a switch:

e-Series Dual Circuit Plus™ Battery Switch - Blue Sea Systems

This thing here is called a circuit breaker:

ST CLB Circuit Breaker Block - 6 Position with Negative Bus - Blue Sea Systems


3. They set up their diagram for boats, basically, where they want full isolation for both batteries, so you can store them off.

4. Just ignore the Blue Sea set up, unless you are looking at leaving your truck sitting for a LONG time and you are going to have a trickle charger on your batteries. If you are looking at a different set-up like this, I would recommend posting up a new tech thread posting in the appropriate vehicle tech section and spell out all of your equipment, your truck type, what your goals are etc. You will get people who know more than me about electronics to chime in to your unique situation.
 
@weejub you're the man. Thanks a lot for taking your time to answer all this. It makes quite good sense what you're describing with a boat owner who wants his batteries in storage mode. I am pretty sure that I am going to do the exact setup that you show me.

Phew I'm glad that I asked and I did not start on ripping cables of my starter.

Once again, thanks a lot! :)
 
Thanks, but the set up and all the knowledge came from the folks on this thread. The diagram coming from @Cruiserdrew and so many people here made my truck happen - still indebted to them!
 
Hey again!

So @weejub, I followed your advice and put it in as suggested. Here's some pictures!!

With the wires pulled over the bar in front of the radiator, I wasn't able to close the hood, so I had to pull them where the line to the expansion tank used to be (perfect fit!).
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Secured and all (with a luggage strap, yes, but that's what I have for now).
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Done at a campsite in Colombia.
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Here's how I keep an eye out for the battery voltage on the extra batteries. Top left is a three-way switch that allows us to turn the cars internal fans on and run them with the extra batteries (comes in handy when there's no air movement in warm areas) to not run at all or to run normally. Top middle is diode that tells me when the vsr relay is charging. Top right voltmeter. Bottom right: switch for voltmeter so it doesn't light up the car when we're trying to sleep. A little outside of the picture, a 150w DeWalt inverter with a 115v outlet and two USB outlets.
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Thanks!

Yes I grounded my acr/vsr to negative. No I did not put in fuses between battery and switch. Oh yeah that would be ideal. For now I'm going to go with this. I only expect the truck to be mine for another four months. And then another overlander will hopefully buy it when I hit argentina!!

Cheers!
 
You really should fuse the + leads off the battery. If one of those wires chafes or gets compromised, you'll have a dead short and then an electrical fire. Plus the location of your wiring leaves them very exposed with lots of potential for chafing and/or damage in a front end collision. Very easy to fuse these with an MRBF at each battery. Your current set up looks functional but unsafe.

At a minimum, let the person you sell you truck to know about this potential issue.
 
Id loom the wires, and tuck them under the rad support they are currently laying on top of. You can tie wrap the loomed wires to the existing wiring harness that runs there.
 
I sleeve all wires ALL including primary battery cables with split loom then tape wrap. They are also anchored to surfaces with proper sized clamps so they do not move. I use the Blue Sea item @weejub linked above. I run them down and through the cross member rather than across the top of the rad support.

I learned a great deal about wiring playing with boats when I lived in the Keys. I saw several boat fires over the years caused by slip shot wiring, scary as hell when out on the water. Point being, you can never be too safe. Spend more on safety than anything else.
 
Frkens said:
@Cruiserdrew thanks for your input! I did put in a fuse between the battery and the inverter if that's what you mean?
Click to expand...

No. The heavy 2ga leads coming off the + battery terminals, need to be fused right at the battery in order to be safe. I also agree with others that your routing of the wires is not smart. The channel under the radiator support would be an improvement. Wrapping in wire loom is also a good practice. You have th ingredients of a good install here, just put in a bit more effort and make it right. But fusing at the battery is not optional.
 
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