Need confirmation on dual battery setup for '07 Silverado Classic

[Smoky]

From what I've gathered from posts here and elsewhere online, I've decided to set up a dual battery system on my '07 Silverado Classic using a Blue Sea ML-ACR Automatic Charging Relay w/ Manual Latch, Blue Sea Terminal Fuse Blocks, and Blue Sea 100A Terminal Fuses. Here is how I THINK it's supposed to be wired:

• Install fuse block and 100 amp fuse on positive terminal of starter battery
• Install fuse block and 100 amp fuse on positive terminal of auxiliary/house battery
• Connect positive post on starter battery to primary battery post on isolator
• Connect positive post on auxiliary/house battery to auxiliary/house battery post on isolator
• Connect negative post on starter battery to ground on engine or frame (or to positive bus)
• Connect negative post on auxiliary/house battery to ground on engine or frame (or to positive bus)
• Battery-to-isolator connections to be made with 4 awg copper wire

I'd appreciate it if someone with far more knowledge than I would review this installation procedure and let me know if it's correct, or if I'm missing something.

Many thanks in advance...Smoky

 

[dwh]

Looks good. No idea what you mean by "positive bus" though...

 

[Smoky]

Thanks dwh and Verkstad. My thought is to establish a common ground using a bus bar instead of separately grounding each negative wire to different places on the engine/chassis.

 

[DiploStrat]

Thanks dwh and Verkstad. My thought is to establish a common ground using a bus bar instead of separately grounding each negative wire to different places on the engine/chassis.

As Verkstad mentioned, you mean "negative" bus. Worth noting, your vehicle's chassis IS your negative bus and that is what you should use. Just don't try to ground a big load to a small cross member, or similar. Stick to the main frame rails (as does your vehicle manufacturer) and you will be fine. The key thing is that the connections must be good - no rust or paint, etc.

If you are bored, you can Google up some articles on the dangers (small) of using a dedicated ground wire instead of the frame rail. The point is that you are eventually going to end up at the same place.

Other comments:

-- Wire runs under 18-24" don't need a fuse. (Assuming properly sized wire.) Fuse is critical on long runs that could be pinched or have the insulation wear off.
-- Wire gauge is a function of length and desired charge rate. The longer the run the bigger the wire.) If everything is under the hood, you need not go any larger than the factory wire.

We'll skip the discussion of voltage drop vs. resistance. Suffice it to say, a small wire can't pass as many amps and will make the charge slower. Small enough and slow enough = no real charge at all. (A not uncommon situation.) Bigger wire will, within reason, result in much faster charge. The final voltage will be the same, regardless of wire size - the question is whether you will ever pass enough amps to reach the desired final voltage.

 

[Smoky]

Yeah...my mistake. I did this on my boat when I rewired it, and it cleaned things up nicely. I don't hear of many examples of folks using busbars with their vehicles, though.

Ok. In that case, would be referred to as "negative bussbar".

 

[Smoky]

I'm just looking for a way to reduce the number of wires and ground points....worked nicely with my boat. Overkill? Perhaps...

As Verkstad mentioned, you mean "negative" bus. Worth noting, your vehicle's chassis IS your negative bus and that is what you should use. Just don't try to ground a big load to a small cross member, or similar. Stick to the main frame rails (as does your vehicle manufacturer) and you will be fine. The key thing is that the connections must be good - no rust or paint, etc.

If you are bored, you can Google up some articles on the dangers (small) of using a dedicated ground wire instead of the frame rail. The point is that you are eventually going to end up at the same place.

 

[DiploStrat]

I'm just looking for a way to reduce the number of wires and ground points....worked nicely with my boat. Overkill? Perhaps...

We're talking past each other. You are going to run a wire from the negative terminal of your second battery to some point. In my case, the battery is 20 feet away, so grounding to the frame is much easier that running another wire all the way to the front of the truck. If you are under the hood, just run down to where ever the factory battery is grounded. If the batteries are adjacent, ground to the factory battery as you know that it is grounded to the frame.

 

[Smoky]

Got it...thanks.

We're talking past each other. You are going to run a wire from the negative terminal of your second battery to some point. In my case, the battery is 20 feet away, so grounding to the frame is much easier that running another wire all the way to the front of the truck. If you are under the hood, just run down to where ever the factory battery is grounded. If the batteries are adjacent, ground to the factory battery as you know that it is grounded to the frame.