Hi all,

I want to install a second battery in my 2015 Suburban. I browsed on gmpartsdirect.com and found a list of items for the 2015 Suburban under "Auxiliary Battery":

• 14005061 HOLD DOWN
• 22989633 BATTERY TRAY
• 22829069 SUPPORT
• 23239735 FUSE BOX
• 23307762 NEGATIVE CABLE
• 23249196 POSITIVE CABLE
• 12135194 RELAY

I then went and looked under the hood of my Suburban and it already has the auxiliary battery tray on the driver's side of the car (in the front near the radiator). Also, I already have a "Priority Start" unit so I believe I don't need the relay or fuse box. Finally, I already have 8ft of 4 gauge battery cable with 3/8 lugs on either end of both cables.

From what I can tell then I need:

• The Support

• The Hold Down
• A group 48 battery

Can someone confirm this sounds correct? Also, I'm pretty sure both the support and hold down won't come with the requisite mounting hardware (i.e. bolts) so if anyone could suggest how I can figure out what mounting hardware I need for those parts I'd be much appreciated!


Thanks!

 

Quick update here. I've since determined that I don't need the battery support tray (the factory-installed battery tray is already sitting on top of a support installed by the factory as well). I've also gone ahead and ordered the battery hold down and bolt since I'm pretty sure I need those.

I only have 1 remaining question really which is what type of battery I should use? My Suburban has a 94R in it from the factory. However, I purchased a second 94R in an effort to match it and while it does "fit" onto the battery tray it extends over the end of the tray about a half an inch. So I'm guessing that second battery tray was not intended for a 94R. Now I'm trying to decide if I should return the 94R and swap it out or just live with the slight overlapping. Does anyone happen to know what size battery the second battery tray was actually designed for?

 

That surprises me that the platforms for the Batteries aren't the same size.
Beyond that, though it's not mandatory, you should use identical batteries in capacity. Also, the connecting "Positive" lead for the supplemental battery should be the same gauge, or one size larger than the one used for the original battery. Definitely the next larger gauge if the cable is more than twice the length of the original.

 

The existing battery cable appears to be 6 gauge so I think I'm OK using 4. As for the battery, I decided to go ahead and just use the 94R even though it overlaps the end of the battery tray a little. I'm pretty sure that once the retainer and bolt are in place it won't be going anywhere. As you said, I'd rather do that so I have near identical batteries.

 

If there's any possibility of a sharp edge of the tray damaging the bottom of the battery, you could lay a properly sized piece of metal/wood down under it. Sort of a shim.