Dual Battery Setup with Blue Sea 7650 Add a Battery

[Gator1996]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

I don't want to hijack so I hope the OP is getting something out of this also.

So I have a stereo, LED lighting, GPS/Fish finder and the standard lighting, horn etc. all connected to my house battery, #2. Engine, starting and charging function on battery #1. Would it be possible to draw more that 300 amps under these conditions? I am thinking at most I'm at 20 amps. If so, would the fuses that Blue Seas specs as part of the install provide protection against failure of the switch? I have the Mercruiser 4 cylinder motor but I'm not totally sure if matters. In case you didn't notice I have no idea wth I'm doing outside of following the instructions that came with the add a battery.

Based on dialogue in another thread, someone, it may have been bruce, said the additional fuses were not necessary in this set up so I figured the fact that I had installed them was an additional layer of security. Now it seems that I may have a false sense of security because blue sea specs that were overkill before now may not be up to spec for my boat. Maybe I need to give them another call.

What's the general consensus; is it possible for me to melt the mini switch?

To the OP sorry. Last question...swear.

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

The only time one would be drawing current to get near the max of the switch would be due to the starter current and only during starting. Your 4 cylinder engine wouldn't come close to being a problem.

The fuses you are referring to are the ones between the battery and the ACR and they are to protect the ACR in case one battery was severely discharged and the ACR joined the 2 batteries. The reality is that the ACR would not allow the connection between the 2 batteries in that scenario since the voltage would be below the ACR threshold for the discharged battery.

You shouldn't have a problem with the mini switch with your engine.

If you want to take the conversation off line I am ok with that if you want to shoot me a PM.

 

[Gator1996]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Good enough. Thanks for time and expertise. Much appreciated.

 

[Im Lon 2]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Are there instructions on how to hookup the ACR to the ignition switch?

Also what gauge wire should be ran?
Battery to ACR
Battery to Switch
ACR to Ignition
ACR to Ground

Sorry not trying to hijack thread. Very informational thread by the way.

Thanks

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Best is to go to the BlueSea site as they have some very good diagrams. You can then go on here or start new thread and ask questions for anything you don't understand.

ACR does not wire up to the ignition switch unless you want to disable it while engine starting.

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Good enough. Thanks for time and expertise. Much appreciated.

I looked up some more specs on the mini switch:

Specifications
Cranking Rating (10 sec.)
1,000 Amps
Cranking Rating (1 min.)
650 Amps
Intermittent Rating (5 min.)
450 Amps
Continuous Rating
300 Amps

These are actually very high ratings. Better than I expected. Definitely fine for your application.

 

[gapple12]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Wow, thanks for the good feedback. I'm just going to get the standard 7650 120 amp version. The price difference is minimal and not worth chancing.

 

[gapple12]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Do you guys think this set up need a fuse on both power leads to the switch ?

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Not from the batteries to the switch. BlueSea only recommends fuses from the ACR to each battery.

 

[gapple12]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Not from the batteries to the switch. BlueSea only recommends fuses from the ACR to each battery.

Ok, great. I found a deal for one that comes with 2 inline 80 amp fuses. Now, I guess when I wire this setup I will need to determine what power wires on my battery are for motor and what power wires are for all accessories, right ? So I can have one battery for motor, one battery for everything else. I will have to go look, but I remember my battery has a few small gauge connections ( accessory's) and 1 large gauge connection, which I'm assuming is the motor.

 

[Gator1996]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

I followed the installation instructions as written on the Blue Seas website.
Its good that you got the fuses included but I found that the real cost was for the cables. I think bruce may have said earlier that genuinedealz.com is the place to go for cable and I had mine done through their sister site bestboatwire.com . Custom made cables to your specs for less than what some sites charged for the cable alone. Unless you have all the equipment and supplies or just want to make the cables yourself, I don't think you can make them for what you buy them from these guys for. They did great work for me and got them to me super fast.

The mini version did have a connection to run a wire to the ignition switch to disable the ACR while the key is in "start" position and returns to normal when it is back to "run." Good luck

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Ok, great. I found a deal for one that comes with 2 inline 80 amp fuses. Now, I guess when I wire this setup I will need to determine what power wires on my battery are for motor and what power wires are for all accessories, right ? So I can have one battery for motor, one battery for everything else. I will have to go look, but I remember my battery has a few small gauge connections ( accessory's) and 1 large gauge connection, which I'm assuming is the motor.

That is going to be your biggest problem and which is why I didn't use this type of switch on my I/O boat. For example, you don't want the power that goes to your ignition switch and to your gauges to be on the house power because you need that one to start your engine. In my case, I used a 1/2/Both switch for my I/O. For my outboard boat, I can use this the add a battery switch because I could disconnect my fuse panel and I can still start my boat.

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

The mini version did have a connection to run a wire to the ignition switch to disable the ACR while the key is in "start" position and returns to normal when it is back to "run." Good luck

If you want to hook this up, you can attach a wire to the starter slave solenoid or starter solenoid and run this to the ACR rather than running an additional wire all the way to the helm.

 

[gapple12]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

That is going to be your biggest problem and which is why I didn't use this type of switch on my I/O boat. For example, you don't want the power that goes to your ignition switch and to your gauges to be on the house power because you need that one to start your engine. In my case, I used a 1/2/Both switch for my I/O. For my outboard boat, I can use this the add a battery switch because I could disconnect my fuse panel and I can still start my boat.

I see what you mean. I will have to test each wire with power and meter it at the switch and panel to see what is still getting power. I'm really only doing this addition since we like to sit for long periods of time with kids swimming at anchor. I have a bad habit of forgetting to start the boat before the battery drains and now that Im adding a larger sound system with amps as well as many LED swimming and interior lights, the second battery is a must. Maybe I just run the sound system and LEDs on the second battery only. Hmmmmm

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

Maybe I just run the sound system and LEDs on the second battery only. Hmmmmm

Yep. You still have it to start the boat in the "combine" mode if you happen to have issue with the other battery.

 

[mccollum74]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

I have a 1100 watt stereo system in my boat. It was in there when I bought it. The previous owner only had one battery in it. It's been that way for 3 seasons now. Should I consider a second battery?

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

I have a 1100 watt stereo system in my boat. It was in there when I bought it. The previous owner only had one battery in it. It's been that way for 3 seasons now. Should I consider a second battery?

Depends on how loud you play the stereo and how long you play it.

 

[gapple12]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

OK, I'm curious when running the blue sea dual battery setup if both batteries need to be the exact same ? In other words, I have a barely used ever-start battery and I am buying a Sears marine battery. Both are different sizes, different brands. Any problem with this for charging ?

 

[bruceb58]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

OK, I'm curious when running the blue sea dual battery setup if both batteries need to be the exact same ? In other words, I have a barely used ever-start battery and I am buying a Sears marine battery. Both are different sizes, different brands. Any problem with this for charging ?

No. Shouldn't be a problem as long as they are both flooded lead acid.

 

[gapple12]

Re: Dual Battery Setup with Blue Sea 7650 Add a Battery

No. Shouldn't be a problem as long as they are both flooded lead acid.

Great, thank you