Best first gen dual battery design?

After way too much reading I’m not finding much help here for a dual battery set up for the first gens. Ideally under the hood. I see one short awkward video where the guy pit it under the hood behind the air filter but on both my first gens there’s a contraption in the way of that battery and the video says nothing about what he did with that. Other ideas are under seat in xtra cab ( I have a double) or putting them in the bed. A local guy that does them here said to replace the air filter with a cold air intake , which I consistently read is a waste of money, and that will open up that front corner to put in a battery. Surely someone has figured out a better way right? 2 batteries under the hood should be do able right?

 

If you do 2 battery's under the hood do not do the 2 side by side design. @otis24 did that and he core support ended up cracking.


The thing in your passenger side wheel well, it's either your ABS stuff or your cruis control stuff. The guys without those options are lucky enough to be able to put an extra battery there... unless you delete those options on your truck (which are *relatively* doable) you're limited to what you said behind the seat or in the bed.

I'm in the process of planning out a dual battery setup and I'm lucky enough to only have cruise control which I'm deleting so im going to make under the hood work.


If I were you I would either do it in the bed to preserve cab integrity..... or delete my ABS lol

 

I forgot about the ones that did the two in the same spot. I quickly ruled that out when I saw that they were getting cracking. Thanks for the info. Really don’t want to delete cruise.... no real idea what ABS actually does. Hmmm...

 

Yup, my drivers side headlight is all crazy.

My solution was get rid of the bed and build a camper in its place and put the batteries there.

 

I love quoting your build any chance I can, freekin love that camper of yours!


@Natenite I'm contemplating leaving my cruise control in there is enough room without all that ABS stuff that you can move your starting battery (smaller group size) on the passenger side and then but a bigger battery for all your accessories in the original battery spot.


I've never driven a tacoma with ABS but I've been told they don't work well with the rear drums. Just some else's personal experience... since it was an option these trucks will drive just fine with out it. As far as removing it goes, that can be a can of worms. No ABS is simpler but you'll have to bend all brand new brake lines for your truck I'd imagine possibly different brake valves in some places

 

Just youtube some setups, you can put the 2nd battery anywhere tbh, i wouldnt cold air intake, or you can go with a goal zero setup, but if you go with a dual battery i suggest redarc, ima get a goal zero in the future and a solar panel for a dometic fridge in my future, do so,e overlanding and cold air intake would handicap me so i got a snorkel in essence its even “colder”

 

Mines in the bed.
I would have preffeed it in passenger rear seat area since I removed my seats, but comitted to the bed.

 

One of those things everyone has different ideas it comes down to what works in your application .

 

Whatever you do, isolate it from your starter battery. There are plenty of commercial setups, but I saw a video from dirtliftstyle (I know, he's a jeep guy, but he wheels with Yotas, and does cool fabrication projects).

Anyhoo, he did a dual battery setup on his tow rig, and basically just used an ignition operated solenoid to isolate the 2nd battery. So when the ignition is on, the circuit is connected, and the battery gets charged off the main charging system. When ignition is off, it's isolated and can't drain your starter battery.

EDIT: he used a relay, not a solenoid... derp...

 

Here are some pics

 

Dual Deep Cycle/Starter batteries aren't actually deep cycle. At least not compared to a true deep cycle battery.
IMHO you compromise so you get a battery that isn't a very good starter battery and isn't a very good deep cycle battery. But, if you can only have one battery that's a different story.
It's like a hybrid bicycle. It sucks on pavement and it sucks on dirt.

 

This. The guy I bought my truck from had setup a dual battery system, he moved the cruise control box further forward on the passenger fender wall, and mounted the battery on the passenger side. he used something from this company https://stingerelectronics.com/products/500-amp-relay-and-isolator . Its dark now but ill post a picture of it tomorrow morning for you.

Here are the pictures.

 

That makes sense.
Those stand alone units are super nice.
I currently have a pair of golf cart batteries. They're crazy heavy! 120 pounds for 230ah (115 usable ah).
When lithiums come down in price some day I'm going to switch to a stand alone system. There are lots of DIY ideas for those as well.

 

I dont know if you made any progress on this, but as someone who has spent far too much time and money modifying their first gen Tacoma, DO NOT go removing factory equipment like cruise control or ABS equipment. First of all, the equipment in the passenger corner is ABS and is required by law. Second, all of this was designed by Toyota engineers who know what they are doing, not a bunch of dudes who think they know what they are doing on a forum; if you start removing critical equipment you are going to start having problems or lose your life in an accident.

If you want to install a dual battery setup, get two sealed batteries like Optima Yellow Tops or Odyssey AGM batteries and install them in the cab. I'm probably the dude whose video you mentioned where they installed a battery behind the intake; but I removed that battery and reinstalled the factory intake (you are correct, cold air intakes are garbage and a waste of money). I bought two Optima Yellow Top batteries and installed them in the cab, but I'm also not happy with their performance. I'm looking to replace them with something different, possibly Oddysey. My current setup is dual yellow top batteries, Blue Seas selector switch, Blue Seas Solid State ACR/Isolator, and new/upgraded wiring plus "Big 3" wire upgrade.