Dual Battery Setup using OEM parts?

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Californian

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thanks for the wrieup. I have a 2018 tahoe and i am planning on doing a dual battery setup also. This helped me map out the layout, but I think im making my own since I plan on running 1/0 cable to both with a bigger alt upgrade. I think I will just run parallel with a relay for an isolater when needed. I am also trying to figure out how to get a H7 into the driver side tray so I have matching batteries. anyone able to pull that off yet?
 

bad_idea

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Thank you so much for documenting all of this information guys. I went to Windrock this weekend (Yukon XL tow rig, XJ for the trails), and left the Yukon sitting for the four day weekend. I kept the luggage in the back of the Yukon and was in and out of it all weekend. Went to start it up yesterday and the battery was dead. Had to jump start it.

Will be installing a second battery soon enough.
 

Rubicon26

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Quick question, the #9 on my ppv feels like it is getting hot and losing power, the lights are going dim and then eventually off, can it be bypassed?
 

DarkKnight

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This is a great post and thank you to all of the contributors for sharing the information on setting up an oem style dual battery setup. I'm working towards this for my 2017 Yukon XL Denali and have a question about the oem negative cable.

I've seen a great deal of posts/comments/videos elsewhere that the negative cable on these trucks for secondary batteries ought to/needs to run through the ring shaped current sensor located on the negative cable near the primary battery. However, the oem cable runs ~2 feet from the secondary battery to the engine block, and that's it. When there are dual batteries from the factory is there another sensor or is there a reason this is not important when using the oem connections?

Also, and I didn't note this elsewhere, the bolt for attaching the negative cable to the engine block is an M10 x 1.25 in case anyone else needs that information.

Thank you for indulging my first post.
 

Doubeleive

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This is a great post and thank you to all of the contributors for sharing the information on setting up an oem style dual battery setup. I'm working towards this for my 2017 Yukon XL Denali and have a question about the oem negative cable.

I've seen a great deal of posts/comments/videos elsewhere that the negative cable on these trucks for secondary batteries ought to/needs to run through the ring shaped current sensor located on the negative cable near the primary battery. However, the oem cable runs ~2 feet from the secondary battery to the engine block, and that's it. When there are dual batteries from the factory is there another sensor or is there a reason this is not important when using the oem connections?

Also, and I didn't note this elsewhere, the bolt for attaching the negative cable to the engine block is an M10 x 1.25 in case anyone else needs that information.

Thank you for indulging my first post.
on mine I eventually had a longer ground cable made connecting the grounds on both battery's, there really is no room in the RVC sensor to run 2 cables, so I just connected the grounds together at the 1st battery. which is how multiple battery setups should be connected anyway.
 

justchecking

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This is a great post and thank you to all of the contributors for sharing the information on setting up an oem style dual battery setup. I'm working towards this for my 2017 Yukon XL Denali and have a question about the oem negative cable.

I've seen a great deal of posts/comments/videos elsewhere that the negative cable on these trucks for secondary batteries ought to/needs to run through the ring shaped current sensor located on the negative cable near the primary battery. However, the oem cable runs ~2 feet from the secondary battery to the engine block, and that's it. When there are dual batteries from the factory is there another sensor or is there a reason this is not important when using the oem connections?

Also, and I didn't note this elsewhere, the bolt for attaching the negative cable to the engine block is an M10 x 1.25 in case anyone else needs that information.

Thank you for indulging my first post.
On my 2011 I ran the aux battery negative to the primary battery negative and the aux battery positive thru the hellroaring isolator to the primary battery positive. It worked perfectly. I used the newest battery as the aux.
On my 2019 I followed the 2019 oem method and ran the oem negative cable from the aux battery negative to the block. I ran my aux battery positive thru the hellroaring isolator to the starter positive. Again I used the newest battery as the aux. It works perfectly as well.
My service manager said it looks great and thought there would be no impacts with any future warranty work.
 

raspino

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thanks for the wrieup. I have a 2018 tahoe and i am planning on doing a dual battery setup also. This helped me map out the layout, but I think im making my own since I plan on running 1/0 cable to both with a bigger alt upgrade. I think I will just run parallel with a relay for an isolater when needed. I am also trying to figure out how to get a H7 into the driver side tray so I have matching batteries. anyone able to pull that off yet?
I am planning on starting a project for my 2017 Tahoe. Which tray did you use, most of the trays I have seen do not list 2017 as compatible.
 

justchecking

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I am planning on starting a project for my 2017 Tahoe. Which tray did you use, most of the trays I have seen do not list 2017 as compatible.
IMG_4700.jpeg

And truth be told you could modify the incomplete tray that is already in there. It is just missing a little piece of metal that traps the bottom of the battery on one side and the welded nut on the other side that the hold down screw and rubber block attaches to.
 
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pwtr02ss

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Old thread but very helpful. I plan to do this to my Yukon soon.
 

VonZipper748

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For anyone interested in doing this, I've learned a couple things. First, before I forget, in addition to the parts I've listed above, you'll also need the positive battery post cover. Part # is 22945779. It has been discontinued, but you can still find them on Ebay. You'll also need the battery tray, and battery hold down, and bolt, parts # 2 and 3 in the pic in my first post. Part # for tray is 23231841, the hold down is discontinued, but you can get them on Amazon.

I realize this isn't for everyone, there are less expensive ways to do it. I just wanted to stay as OEM as possible. I mostly accomplished this with one exception. This is for my 2020 Tahoe, depending on your year, your configuration might be different, although I'm pretty sure 2015-2020 stayed the same.

I have no connection with them, but I like buying from GMPartsDirect, good prices and fast shipping.

The one exception I mentioned above, is that my truck didn't have the wiring connection for the Isolator Relay. GM must have decided to remove that wiring at some point unless it was for a PPV. What I ended up doing is just removing the relay and isolator from the new wiring harness, and then I bought a VSR (voltage sensitive relay) from Keyline Chargers. I actually like this better than the OEM relay and isolator, it's a cleaner install, and supposedly there is no parasitic voltage draw from the OEM Relay. So, if you decide to do this, you may not want to buy the "Accessory Power Relay", part # 12135194. I have a brand new one if anyone needs it as I can't return it.

Overall, I'm really happy with how it turned out. It's mostly OEM, with the Isolator being the only exception.

When you do this, the new positive battery cable (84355668) has both the positive cable for the fusebox, and the positive cable for the aux battery tied together in the same loom. You'll end up removing your existing positive cable and not reusing it.

If anyone has any questions, I'll try and answer as best I can.

I ended up making a bracket for the Keyline Isolator instead of mounting it directly to the firewall.
I have a 2017 suburban midnight edition and doing something similar to you. I just have to finish doing it. The one I went with has a voltage wire and and jump wire so the AUX battery can jump the main one if it ever goes dead. But yours is very clean nice work
 

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