"House" battery question (Amp Hours and Deep Cycle vs Starter)

[Martinjmpr]

OK, second battery purchased last night! Also got the hold down. I still need a bolt for the hold down but I can get that at the hardware store. Hoping to get the 2nd battery connected this weekend! Getting actual power to the interior may take a bit longer but the battery was the tough part. Everything else should be easy.

 

[Martinjmpr]

Martin,

you will not be reusing that corner brace so you can remeasure without it in place. My 2nd battery has exactly the same dimensions as my starter/house battery and there is no way the brace is going back on there. The battery tray below will be taking over the "bracing" duties.
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Jel

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Oh my gosh, I totally missed that you didn't use the corner brace! OK, well that makes installation a bit easier!
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Hey, dumb question, do you still use the metal rod brace that runs diagonally across the top of the starter battery behind the driver's headlight? Since my battery has top terminals I'm a little worried about having a piece of metal running across there. Just wondering how necessary that brace is.
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This is the one I'm talking about, the diagonal one.

 

[Martinjmpr]

You could simply place a rubber hose or similar insulation on that bar.

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Hmmm...I put a piece of wire loom on there but I think rubber would be better. I wonder if I can find some pipe insulation that's that small? Bet I could make something....

 

[Jelorian]

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Hmmm...I put a piece of wire loom on there but I think rubber would be better. I wonder if I can find some pipe insulation that's that small? Bet I could make something....

I do still have mine. I admit I had a couple of sparky accidents when messing with the positive terminal hardware.

For some reason I didn't even think of covering it with something made of rubber. That being said I'm going to put a couple of layers of heat shrink tubing on it. A short section of rubber hose split down the middle and some tie wraps would work just fine as well.

Good luck with finishing up the install!

 

[Martinjmpr]

I do still have mine. I admit I had a couple of sparky accidents when messing with the positive terminal hardware.

For some reason I didn't even think of covering it with something made of rubber. That being said I'm going to put a couple of layers of heat shrink tubing on it. A short section of rubber hose split down the middle and some tie wraps would work just fine as well.

Good luck with finishing up the install!

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Well, the new battery is in, positive terminals are connected. Ran out of time and didn't get a chance to finish it up.
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I connected to my starter battery using the top terminals - since this put my electrical connections too close to the brace I just left it off. I honestly don't even know what that brace is for but at least for now I think I can live without it.
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Next I have to figure out how I'm going to install my Blue Sea Fuse block. Since mine won't attach to the battery terminal (like yours) I may attach mine to the firewall using jack nuts, just as I did with the isolator.

 

[Jelorian]

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Next I have to figure out how I'm going to install my Blue Sea Fuse block. Since mine won't attach to the battery terminal (like yours) I may attach mine to the firewall using jack nuts, just as I did with the isolator.

Martin, IMHO, I would see if I could return the one you got and get the version I got. Since it mounts directly to the terminal bolt, you elminate having to do some additional steps to get yours mounted.

With the fuse block that you currently have you'll have to still drill into the firewall, then you'll have to create a cable that runs from your battery to the fuse block itself, since it is not directly attached to the battery terminal. IMO, not worth the hassle of having to do all of that.

Whichever route you go, good luck on getting it all setup.

 

[Martinjmpr]

Martin, IMHO, I would see if I could return the one you got and get the version I got. Since it mounts directly to the terminal bolt, you elminate having to do some additional steps to get yours mounted.

With the fuse block that you currently have you'll have to still drill into the firewall, then you'll have to create a cable that runs from your battery to the fuse block itself, since it is not directly attached to the battery terminal. IMO, not worth the hassle of having to do all of that.

Whichever route you go, good luck on getting it all setup.

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Yeah, I ordered it from Amazon and I'm past the return window by quite a ways. I agree it would be easier to put that kind on and my loss would be the ~$25 I paid for the fuse block I have (unless I can sell it to someone or use it somewhere else.) I may go ahead and order it - I can't really use the fuse block until I push my wire through the firewall and then figure out where my auxiliary 12v outlet will be. I'm going to have to pull the console apart for that anyway, will probably be an all-weekend project.
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Hey, here's a dumb question, while I'm on the topic: Once I get my battery all installed, with the add-a-circuit connected to the fuse block and a 10a circuit in there - how do I know if the isolator is working properly? Am I right in thinking that a battery being charged should show 14 - 14.5v? So if I start the truck and run the engine and test the 2nd battery, if it's showing 14.5v, it is charging. But how do I know if it is "isolating" when the ignition is off? Is there any way to test that?
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EDITED TO ADD: I guess I could do this: With the engine running, pull the fuse out of the add-a-circuit. That deprives power to the isolator, which should shut off, yes? And that, in turn, should lead to an immediate drop in voltage to 12.7 or so. Does that sound right? Is there a better way to test the isolator?

 

[DiploStrat]

Most relay isolators will make a loud "thunk" as they open or close.

As you noted, when closed, the voltage at the second battery will rise towards the voltage of the charging circuit. When the relay is open, it will drop. How much depends on the state of charge of the second battery and the number of loads. The speed of the drop will depend on the state of charge (SOC) of the second battery.

Soon, if the second battery is hammered and has been on charge for only a few minutes, the voltage drop will be rather noticeable. If it is fully charged, the drop will be minimal.