Battery beginner here. I have an XJ which doesn't exactly have a lot of spare room under the hood. I've seen people who have removed the airbox and put a second battery there, but I have a snorkel and need the airbox where it is. Is it possible to have a second battery in the back of my rig? How would I go about using a dual battery setup like this? I can tinker around under the hood tomorrow and see what can be done, if anything. But, I think the battery would have to go elsewhere. Any ideas?
Hit up YouTube and Google. I know there are a few good kits out there. I don't own a Jeep so I can't provide better advice. I have seen some online video installs when looking at dual battery related products.
Benefactor
I've seen too many dual battery setup issues to justify having it. A solar panel and/or jumper pack is much simpler, cheaper and reliable. Find the largest battery you can fit in your battery box. Maybe you can make it larger. I can just fit a Group 31, though it did require extending the ground cable by a few inches, under the hood. I also used that as a chance to upgrade the cable terminals to a military style.
If you decide to run a dual setup, with one in the rear of the Jeep, you'll need to run some very large mamba jamba cable. What are your power needs off the second battery? Run your winch (if you have or plan to get one) from the main battery. If the controller craps out you won't have to rewire it to do a recovery. This happened at OTG this year. The winch was wired to the second battery, controller stopped charging and the winch couldn't be used.
No matter what you end up doing, just make sure the battery strap is nice and stronger and securely holds the battery in place.
If you decide to run a dual setup, with one in the rear of the Jeep, you'll need to run some very large mamba jamba cable. What are your power needs off the second battery? Run your winch (if you have or plan to get one) from the main battery. If the controller craps out you won't have to rewire it to do a recovery. This happened at OTG this year. The winch was wired to the second battery, controller stopped charging and the winch couldn't be used.
No matter what you end up doing, just make sure the battery strap is nice and stronger and securely holds the battery in place.
Benefactor
Ahh yes, the Medusa that becomes your accessory wire connections. Look into getting a Blue Sea fuse box. They make a 6 and 12 terminal version. I counted about a dozen wires off the main and aux terminals on my battery. None of them were labeled and my OCD would freak out everytime I looked at it. Over the years it just grew and grew until I had to do something about it. Each terminal in the box has it's own fuse and the cover has labels so you know what you're looking at. And the cover will hold a spare fuse.
You'll need a single fuse rated just above the total rating of the fuse block. I think the 12 version is around 125A. Put this fuse as close to the battery as possible. From there you can run your cable to the box as long as needed. The block makes everything very organized and easier to troubleshoot if your equipment isn't working.
https://www.bluesea.com/products/category/16/61/Fuse_Blocks/ST_Blade
I run the following through the block:
x2 Outer front roof rack HID lights 35W each
x2 Inner front roof rack HID lights 35W each
x1 LED rear roof rack work lamp ~15-20W (I think)
Yeaseu 8800 HAM radio 55W
50 qt. ARB
CB radio
Blue Sea dual USB cigarrette plug adapter
x3 Binnacle switches for the roof rack lights
You'll need a single fuse rated just above the total rating of the fuse block. I think the 12 version is around 125A. Put this fuse as close to the battery as possible. From there you can run your cable to the box as long as needed. The block makes everything very organized and easier to troubleshoot if your equipment isn't working.
https://www.bluesea.com/products/category/16/61/Fuse_Blocks/ST_Blade
I run the following through the block:
x2 Outer front roof rack HID lights 35W each
x2 Inner front roof rack HID lights 35W each
x1 LED rear roof rack work lamp ~15-20W (I think)
Yeaseu 8800 HAM radio 55W
50 qt. ARB
CB radio
Blue Sea dual USB cigarrette plug adapter
x3 Binnacle switches for the roof rack lights
Off-Road Ranger I
Well, I've got the solar panel in mind. However, my power needs as of now are only a winch and a plethora of off-road lights. The current main battery is crowded with cables. Upgraded terminals are in the near future. The future can contain a number of things, including a fridge perhaps. But I don't know if I would go that far. I just started building my rig maybe 5 months ago. So, this upgrade wouldn't happen right now. A secondary concern would be losing an alternator on the trail. This happened to my father when I was a little fella, in the middle of the Rubicon Trail. LONG story short, having a second battery would've been nice!
If your power needs are only a winch and spot lighting the International Space Station, it sounds like you may need to invest in a higher output alternator and perhaps the largest battery you can fit in the stock location. Your main power requirements appear to be engine running activities, correct me if I am wrong. Folks that generally need a back up battery often have engine off power requirements such as running CB and HAM radios or an inverter.
I'm not sure how much it will help, but there is a great write up on a dual isolated battery set-up on theroadchoseme.com. He's built up a JKU to travel around Africa for the next 2 years. Check it out if you get the chance.
