Blue Sea ACR Wiring Question

[Scott B.]

I am adding a 2nd battery in my truck, and am planning on using a Blue Sea 7622 ACR for charging and isolation. My question is regarding wiring it.

Looking at the diagram (left side, third page) of the instructions, it looks like all I need to do is run a new cable from the +12 post of my starting battery (which also contains the alternator output) to the ACR then to the 2nd battery. Is it really that simple?

(I realize I need a ground wire for the second battery, and need to wire the control switch.)

Thanks.

 

[4RunAmok]

It really is that simple... The posts should be labeled, one battery to one post, other battery to the other. The ACR will take care of the combining for you.

Make sure you run a ground of the same size wire (hopefully something hefty, 4 gauge or better) to either the main battery negative or to the frame, if you choose frame, use a wire wheel and remove any paint/undercoat.

If you're running a LONG run between the two batteries, make sure and put circuit breakers (150 amp) at BOTH ends within 18 inches of each battery.

 

[Scott B.]

How long is "long"? My second battery is in the bed - maybe 8 feet of wire from the starting battery.

My current battery wiring is 4 gauge - I was planning to continue with 4 gauge.

150 amp circuit breaker? I have a 160 amp alternator, and 175 amp fuse as a fuseable link. I was thinking about using 175 fuses.

 

[dwh]

How long is "long"? My second battery is in the bed - maybe 8 feet of wire from the starting battery.

"Long" is: Any place where the wire can get cut/shorted.

Say 8' of wire. You put a fuse 12" from the engine battery. So now you've got 7' of wire from the battery in the bed. If that wire shorts anywhere along that 7' run, it's gonna be a welder powered by the battery in the bed and the fuse next to the engine battery isn't gonna do jack because the power isn't flowing from there.

EDIT: Personally, both my cranking and house batteries are under the hood, so I just use normal battery cables and don't bother with fuses or breakers because all the wiring is under the hood and isn't going to short out against anything.

My current battery wiring is 4 gauge - I was planning to continue with 4 gauge.

150 amp circuit breaker? I have a 160 amp alternator, and 175 amp fuse as a fuseable link. I was thinking about using 175 fuses.

Fuses/breakers are to protect the wire. So if your wire can handle 200a, then go with a 175a fuse so the fuse melts before the wire gets hot enough to melt.

That's also why you use a fuse at either end when doing a battery<->battery hookup. You gotta protect that wire from power coming from *either* power source.

 

[4RunAmok]

Yeah, what dwh said!

 

[Scott B.]

I always run fuses in the circuits I add. However, I didn't think about a "long" battery cable shorting out. I think that is called "missing the obvious."

Thanks.

I don't have room under the hood for a second battery - the 5.0L takes up more space than the old 4.0L V6 that used to be under there. As much I prefer the battery being under the hood, it's not going to work. Besides, with it in the bed, I get better weight distribution. :sombrero:

 

[dwh]

I don't have room under the hood for a second battery - the 5.0L takes up more space than the old 4.0L V6 that used to be under there. As much I prefer the battery being under the hood, it's not going to work. Besides, with it in the bed, I get better weight distribution. :sombrero:

Oh, I wasn't suggesting putting the battery under the hood. I was just saying because that's how mine is, I don't worry about fusing the battery cables.

I've contemplated, several times, moving the house battery back into the van and putting it under the couch, where I have room to put a pair of aux batteries instead of just the one I've got now. If I did that, then, yea, I'd definitely protect the cables with something.

I'll never do it though...this truck is severely old and worn out and every time I start thinking about putting money into it I end up thinking about replacing it instead.

 

[MakersTeleMark]

I used 2ga and fused both ends.

 

[4RunAmok]

I actually don't recommend ANL fuses, you can achieve the same from a breaker, which if it blows, is easy to reset, and you don't have to go looking for a fuse

 

[dstock]

I actually don't recommend ANL fuses, you can achieve the same from a breaker, which if it blows, is easy to reset, and you don't have to go looking for a fuse

Where do you find large amp breakers, like for a winch?

 

[MakersTeleMark]

http://www.wiringproducts.com/contents/en-us/d29_high_amp_circuit_breaker.html

is an example, but probably not enough amps. You should probably just wire in a high amp cutoff switch.

 

[MakersTeleMark]

I actually don't recommend ANL fuses, you can achieve the same from a breaker, which if it blows, is easy to reset, and you don't have to go looking for a fuse

If I blow one of those ANL fuses, it's going to take me a long time to figure out why, and I'll be very hesitant to put power into that circuit any time soon. That's why I went with them. And, they are simple, effective, and cheap. I did consider breaker's, but thought it safer to go with a fused application. Those are 150amp fuses. That's a lot of juice I wouldn't want to just flip back on before figuring out why it tripped, and I don't mind the inconvenience.

 

[theksmith]

for a circuit breaker, bussmann is quality stuff: http://www.amazon.com/Bussmann-Hi-Amp-Circuit-Breaker-Amps/dp/B0024JOKM4/

for the right size wire gauge, google "12 volt wire gauge table" and lookup what size you need for XXX amps over a 8' run. note that the tables vary a bit, go with the biggest gauge you see commonly shown to be safe. i'm guessing 2 gauge will do for a 5% voltage drop on 150 amps, however...

consider that a winch could draw 300+ amps, if your battery in the rear is the only thing powering it then your wire and breaker need to be able to withstand that. if you are splitting that load over both batteries, then somewhere around 1/2 of the amperage is all that will be drawn from each battery (roughly). that's why i went with 1/0 cable when i did my battery relocation to the trunk - both are in the trunk and hope to have a winch up front one day: http://offroadpassport.com/forum/showpost.php?p=13060&postcount=39

 

[dstock]

I was just wondering if I missed something, but could not find a 600 amp breaker for my winch, which is why the ANL solution seems like the way to go where winches are concerned, plus easy to carry a couple spares with the rest of the fuses for my JK. I always know right where they are so there's no need to search for them. I do use a 125 amp breaker for my Blue Sea Aux fuse block, which works great for that purpose.

 

[4RunAmok]

Not familiar with fusing Winches... I installed 3 Ramsey winches this week at work, and didn't fuse even one of them. 2 Gauge wire directly to the battery no more than 4 feet away, loomed the wires and taped it up pretty well.

But if you insist on fusing, again, I'd recommend Blue Sea...

http://www.bluesea.com/products/7554/C-Series Flat Rocker Circuit Breaker - Triple Pole 300A