Battery Relocation

Hey guys, been searching TW for several days now, and found a few very helpful threads, but nothing I could find answered my exact question

So I have been running a dual battery tray in the stock location of my Tacoma for a couple years now. I noticed that the fender had started cracking in the wheel well, though that seemed pretty normal according to several threads on TW. On our most recent trip, it got pretty bad, to the point where my batteries were bouncing around and severed my headlight wires. (I tried re-mounting them a few times, but the sheet metal just wouldn't hold for very long.) I had to resort to temporarily ratchet strapping the batteries down to keep them from wrecking stuff, and repaired my headlight wires in a parking lot on the road!

Now that I'm home, I've pulled the batteries out, and pulled the cage out to find this:



My new plan is to relocate both of my Northstar AGM batteries to either behind the rear seat, or fab a battery box and weld it to the frame. I'm leaning towards mounting in the cab as it's cleaner and safer from water crossings, salty roads, etc. I am aware of many people's concerns about venting, but in my research, I haven't found this to be much of an issue with AGM batteries, and I ran Peterbilt's with 4 batteries under the seat for many years without issue. In any case, I am considering running a vent tube through the floor anyway.

I am going to put two 4-post busses in the stock battery location, then run a 0g or 2|0g wire from the starter battery to the + bus. From there, the alternator, starter, stock fuse panel, and winch will be connected. I will also have the - bus connected to all of the stock locations.

I will ground both batteries to either the body or the frame.

The Aux battery will have it's own circuit to a Blue Sea fuse panel which I already have installed. It uses a 100A breaker. As well, it is connected via a Blue Sea ACR.

My question is what size breaker I should be running for my main starter battery. As far as I know, our starters generally draw around 150-180A. I have a 130A alternator. My winch can pull up to 450A. This lends me to believe I should have a 450A breaker at the battery, however, they are near impossible to find, and very expensive.

Any suggestions, comments, concerns? Appreciate any input!!

 

What did you end up doing here?

 

Be careful putting batteries behind your rear seat. Gases from there can kill you even from so called seal batteries.

 

Seems he has already taken this into consideration and taken mitigating procedures.

 

Posted some pictures of my new setup. Been running it since february. Fabbed up a battery holder and welded it to the body. Been working great so far! I do wish I had used 1 step thicker gauge wire though.

Haven't died yet!

 

The mount has been super solid. Stoked on it. I would use 2/0 gauge instead of 1/0 gauge next time though, as well as do the "big three" mod in 2/0.

For breakers, I have them but never installed them. I still need to do that, just ran out of time and never got motivated to put them in. I did have a plan though, with a full battery kill switch as well.

 

I know this is an older post but I'm thinking of moving my starting battery to the same location.
Besides the 2/0 gauge wire to the Pos bus is there any other changes you would do?
Did you also run a wire from the Neg bus to the battery? I saw the ground to the frame.
Where did you end up placing the main breaker? I'm assuming near the battery?

 

It's really bad, but I still haven't installed the breakers. Plan is to put them by the batteries though. I still have them ready to go. I really need to just get it done. I spend too much time working on other people's vehicles to get stuff done on my own!

Best practice is to run a second ground wire, but that cable is so expensive that I just grounded to the frame on both ends.

It's still been working great. One small thing I've noticed though. At idle all of my lights have a slight flicker. I believe it's because everything is connected to the bus, including the alternator, so the battery isn't there to absorb the "pulses" from the alternator. As soon as I'm driving the flickering is gone.

Never bothers me too much. Truck drives better without the weight in the front for sure. I honestly never even think about my batteries any more.

 

I would be very cautious of battery fumes inside the cab from batteries as they charge.

 

Agm's are sealed and dont give off fumes
Behind the seat is vented
I used to drive big rigs, Kenworth, Peterbilt, etc. They had 4 lead acid batteries under the seat in the tiny cab, no issues.
They only have the small chance of giving off fumes if the seal is broken, and they are overcharged a LOT which heats them up.
Guess I like living on the edge

 

I'd be very interested to see if anyone has mounted their battery(ies) on the passenger side under the bed

 

Some don't as they are no longer living. Your choice.

 

@12TRDTacoma did on the driver side on the frame rail somewhere. There's too much hot exhaust piping and stuff under the passenger side.

 

It's still there. Still kickin' on that very same battery I first put into it 5 years ago. I recently tested it and it measures very close to new CCA. I also did a carbon pile load test on it and it passed stellar.

 

Thanks for the update. You also heard my subliminal message and answered my last question
I was wondering why you didn't run a full-length ground. I haven't priced out 2/0 wire yet. I need to run a piece of rope along the wire path first.
Where did you run your positive wire? Looks like under the cab.
I'm thinking of seeing if 2/0 will fit under the door threshold covers.
Where did you find a breaker large enough for your winch?

 

There are plenty of vehicles that come from the factory with batteries in the passenger compartment.

 

True. However just because auto manufacturers do something doesn’t automatically make it a good idea.

 

They also provide proper ventilation for the outgases that occur. Like I said it is your life and hopefully that is the only one.

 

Proper mitigation is all you need to address the concerns @potstech has. Make sure the battery has proper ventilation and is secured in a sturdy battery tray it'll be a non issue. Half of the vehicles I've owned over the years had batteries in the passenger compartment and it hasn't killed me yet.