Dual battery conversion - need your knowledge/assistance!

Hey folks, so I am just about ready to fork out the bills and upgrade my battery/battieries in the FJ.  Here's my problem - I know nothing about this topic!    I was hoping someone on here might have the knowledge and installation skills to give me a hand. 

I've got a few reasons for this upgrade, all important in their own ways (in my opinion?):

• My '07 FJ is running on the original battery (previous owner had it on a trickle charger, but I am not wanting to do that).
  
  
  
• Warn M8000 winch - althought rarely needed (yet).
  
  
  
• 2-100watt IPF lights, and a total of 12 other 55 watt lights around the truck.  I'm planning on adding an LED bar soon too.
  
  
  
• Powerful stereo system with 500 and 300 watt amps - I enjoy jamming the tunes when camping/tailgating/etc and the truck isn't running, so i want to have no worries of killing the battery while I do this.
  
  
  
• I eventually will be adding onboard air, and other goodies I'm sure.
  
  
  

So here are some of the questions that I've come up with, based on the needs stated above:

• Would you recommend going with a dual battery kit and replacing the original battery as well?  Or would you just upgrade the original battery with one beast of a battery?  I know there's pros and cons to each, but I want what's best for my situation.
  
  
  
• If I went with a dual kit, which one would you recommend?  I've heard good things about the DirtyParts kit, but I also like the in-cab display that the TJM dual kit comes with.
  
  
  
• If I went with a single battery replacement, which one is gonna be MORE than enough for me?  Would it be best to replace the alternator and cables as well?
  
  
  

I'm trying to start this project in the next week or so, and was hoping that someone might be able to help me put a parts list together and assist in the installation.  I pay in good beer, but can also throw some bones in if needed.  If possible, I'd like to save some money on this, but I really just want a clean install with no "shortcuts." Here's my current setup, which is pretty tight for space as it is:



Soooo who wants to help me out??

I replaced my stock battery around 80k miles (I think) with a Sears Platinum and have been happy. I run a fridge too and haven't gone dual battery yet simply b/c I haven't had the time to install. I run a National Luna in my FJ55 and like it but am going to be testing a Piranha set up in prep for carrying them in the store.

If I was you I'd consider replacing your current battery with a quality deep cycle that can handle starting, and then look at going dual setup.

Thanks Steve, that's kind of what I was thinking as well.  My stock battery is older (since '07), but the truck only has 35k miles.  I just worry about the condition of the battery since it's been on a trickle charge for so long until now. 

How often is your fridge running?  And is it ever running while the vehicle is off?

I very often use my fridge and run it for extended periods with the engine off.

Okay cool.  I was leaning more towards the single deep cell as well (for now), and then I would eventually add a second down the road.  In your opinion, would you recommend I upgrade to a high output alternator while I'm at it?  Again, I don't know much about this stuff, but I have heard that it is ideal to upgrade everything (battery/cables/alt) if you want to do it the right way.

I went with the Dirty Parts dual battery kit, it's nice and pretty easy to install.  Second battery is an optima yellow top, time will tell how well it performs.  Also got an S-Pod and 6 switch panel from Dirty Parts, I high recommend both.  Make wiring up accessories super easy.

I've found the link below extra useful and am thinking of a simpler option instead of spending as much cash:
http://www.jeepforum.com/forum/f8/dual-battery-isolated-batteries-winch-welding-1231432/

Speedrye wrote:

I've found the link below extra useful and am thinking of a simpler option instead of spending as much cash:
http://www.jeepforum.com/forum/f8/dual-battery-isolated-batteries-winch-welding-1231432/

See... this is where I need the expertise of someone (cough cough Ryan!) to translate this to where I can understand it... preferably in person... during the install... haha!  I have a decent amount of knowledge when it comes to vehicle modifications and whatnot, but I'll be the first to admit that electronics are NOT my strong point.

DamnItsAGlasgow wrote:

Speedrye wrote:

I've found the link below extra useful and am thinking of a simpler option instead of spending as much cash:
http://www.jeepforum.com/forum/f8/dual-battery-isolated-batteries-winch-welding-1231432/

See... this is where I need the expertise of someone (cough cough Ryan!) to translate this to where I can understand it... preferably in person... during the install... haha!  I have a decent amount of knowledge when it comes to vehicle modifications and whatnot, but I'll be the first to admit that electronics are NOT my strong point.

Ha, I've got a pile of parts for mine that I won't get to install any time soon.  Honestly, I won't be able to do any wrenching on anyone's truck until October-November at the earliest.  If the house sells, it'll be longer than that and I probably won't have a place to work in a rental house.  Put me down for the spring of 2015 and I should be good if I find land and get the next house built quickly... 

LOL!  Well in that case, how does 5:15PM sound on April 24th, 2015?  I don't have anything planned that day, so we should be able to get some quality work in.

I'm pretty sure I've got a doctor's appointment for the kid that's running a little late that day.  I'm really not sure since I don't have any kids yet, but I hear they take up a lot of time.

I completely understand.  Maybe we can do it the following Saturday then, as long as my future workout trainer doesn't call me in to the gym that I've never attended.

So I'm starting to consider going a different route than the dual battery for now.  I keep hearing awesome things about the Diehard Platinum 31M (Sears link here).  Blue room reviews seem to show a lot of people using this solo with winches/stereos/etc and having no issues.  They cost $230 at Sears right now, which doesn't seem bad compared to going the dual conversion route.  Anyone have thoughts/experiences with this?  I also noticed that it fits in the OE tray with little to no adjustments needed at all

I'm running the smaller 34m and it's been flawless.  I went with the smaller one because I think I can make two of them fit on the stock battery tray turned sideways.  It'll be close, and some cutting might be involved, but it'll be unique...  Of course, I'm not going to bother until I have a winch.  Look around online for additional promo or coupon codes for Sears.  I think I got mine for around $159 with discounts.

Yeah I'm definitely gonna try to find some sort of discount codes, it's just hard to find one that's not a fake or expired

I run the Sears Diehard Platinum battery and have for about 30k miles with lights, CB, 2 GPS units (sometimes 3), phone chargers, winch, and CB. It took me well over an hour yesterday without an alternator. Starting with a new deep cycle battery is a good idea, then go to a dual battery setup.

Awesome, thanks for the input!  The Diehard Platinums (all models) seem to be very reliable!

Speaking of alternators... what are you replacing the dead one with?  I've thought about upgrading to a Mean Green alt when I replace my battery, but it's just so hard to pay $400 for it!  I know it'd make a big difference, but it just doesn't seem worth THAT much money!

DamnItsAGlasgow wrote:

Awesome, thanks for the input!  The Diehard Platinums (all models) seem to be very reliable!

Speaking of alternators... what are you replacing the dead one with?  I've thought about upgrading to a Mean Green alt when I replace my battery, but it's just so hard to pay $400 for it!  I know it'd make a big difference, but it just doesn't seem worth THAT much money!

 An OEM alt is $4-500 and a Mean Green is $400. The Mean Green is not a direct drop-in and requires upgrading of a fuse and at least one wire IIRC. Unless you are running a stupid high draw stereo system, or are trying to light your way to Pluto, the stock alt puts out enough juice and has proven to be very reliable.

You could look for a Denso alt, which might save you a few dollars, but I would NOT go with a reman or other FLAPS alt.

Jeez, I didn't know the OEM alt was that expensive! But yeah, if I were to go the Mean Green route, I'd upgrade it all at once.  My stereo has 900 watts in JL Audio amplifiers, so it definitely draws some, but not a ridiculous amount.  And although I've got a bunch of lights (and about to add an LED bar thanks to you!), I really don't use them all at once very often.  I suppose I'll save my money on an alt upgrade until the current one crashes.  Can't wait to get the Diehard though!

A winch will probably be your biggest draw. It can kill a battery quick. That is where a dual battery setup really shines - and also when you run a fridge for extended periods during very hot weather and you don't run your vehicle.

The winch is my main concern, but until I do get the dual setup, I will only use it for last-resort options.  And unfortunately, I do not own an awesome fridge yet

Go ahead and use your winch - but have your vehicle running and don't winch for too long.

Sounds good!