Looking for ideas (dual battery inside cab)

Hello folks,

Like the title of this thread reads, Im looking for ideas for a dual battery system where the AUX is inside of the cab. Ive been thinking of a longer "flat" battery that can maybe fit up behind the seats. To me, this is an ideal location because its centered in the vehicle, which will help with weight distribution. I know i will eventually have a bumper and winch up front and would like to keep weight in the front of the vehicle down to a minimum. Ideally, Id like to be able to have the battery be lithium for the weight savings. I wonder if anyone has done something like this before.

The goal ultimately is to add 100ah of power to the Tundra for accessories, fridge etc. Additionally, powering the system would be done through some sort of solar (eventually).

 

How many passengers do you have on the regular? If you aren't opposed to removing the smaller rear seat there are all kinds of possibilities for platforms and accessories. Some have put fridges in there and the like, and I don't see why you couldn't do a battery plus other goodies there. It also has the advantage of being able to use the seat mounts to secure it all.

 

Thats a great idea, but wouldnt work for my case. Currently, no passengers, but I got rid of the rear seats in my FJ to build a platform for my dogs and promised myself id keep the interior of my Tundra intact.

 

The bonus to the small seat and such is that it can all be readily reversed, but I do understand the sentiment.

Edit: I do understand the sentiment. Damn fingers have a mind of their own.

 

Just be careful what battery you put in because some will off gas when charging and/or discharging.

 

Battery in the cab seems like a bad idea. My 2nd battery is in front of the passenger wheel well in my bed. This seemed a good spot to me because it’s out of the way in front of that wheel well, and it’s helping to counter all the weight on the driver’s side of the truck: primary battery, steering column, driver, fuel tank.

Link to my setup

 

Great input everyone.

 

Awesome setup! If i didnt use my truck regularly for work, I would give something like this a go. A big reason for wanting everything to be in the cab is that i dont have to mess with it coming in and out of the vehicle during the different "setups". Definitely drawing some inspirations though.

 

I hear you. My house battery has been in the way when I haul plywood for a home project. But it only makes it stick out of the bed a few more inches though. I have hauled mulch as well with a tarp covering the entire bed, hanging over the rails, front of the bed, and tailgate. That keeps the battery box from getting funky. Otherwise, I don’t really notice it’s there.

 

I think some LiFePO4 batteries are narrow enough to fit behind the back seat and you could place several of them in parallel to reach your desired AH.

 

I have a 2nd Lithium battery that powers everything but it is in the bed of the truck. Have it in a battery box and it is recharged via solar. You can check it out in my build thread....starts around here.

https://www.tundras.com/threads/the-wallygator-chronicles.65203/page-2#post-1984024

 

Here's the old mans setup which is located in the bed. As others mentioned not sure I love the idea of it in the cab.

 

I wouldn’t suggest a battery inside the cab. I’ve actually seen instances of this where acid gas corroded the inside of the cab over time. Who knows what it did to the driver.

 

OP doesn’t want to remove seats so not much help, and not sure what’s required to carry different types of batteries. No room in the bed, so this is what I did to safely carry an AGM battery in cab. Battery is mounted behind the refrigerator on a mount that replaced the rear passenger seat, mount is removable/seat can be reinstalled. Battery hold down/box is securely attached in a sealed battery box, and AGM battery is vented to outside underneath the truck. Always try to park in the shade, mounting solar panels to the truck didn’t seem useful, so installed a plug for solar on the bed side and use portable panels.

House battery box



House battery accessory fuse panel


Starter battery - isolator mounted on side of battery


Solar charge/accessory power port for house battery

 

If you’re not worried about hitting rocks you can always mount/weld a battery box on the frame under the cab. There’s room and someone here has done it

 

OP that's the one thing you have to consider with the battery inside the cab....heat. Batteries don't like it hot and it's not good to charge them while they are.

 

Again, great info/input from you guys. Certainly giving me ideas. I think what i will ultimately do, is mount a slim battery behind the smaller seat, in its own sealed box. Then I will run some sort of vent tube to the exterior of the truck to avoid any gas venting. Other than trips, the truck sits parked in the garage or in a shaded carport so im not super concerned with heat. Theres nothing ill be able to do to avoid that during trips but ive found that if you try to account for every single scenario when it comes to mods, you'll never be happy so you just gotta send it. This mod is wayyyyy down the list as im still running the OEM battery and have essentially a stock truck but i love to hear peoples ideas way in advance before i start to piece things together.

 

You can fit a small battery in the engine bay up on the passenger side near the cab air inlet/firewall.

You’ll have to fab up a mount but that’s not too hard

 

Hello, good info here. I am in the process of trying to find a good place to mount mine. Just replaced my OEM starting with a AGM, group 27.

I have the Genesis universal single battery kit. Has a tray/and electronics.
Wondering about either under seat (worried about leaks/fumes/etc) AGM is sealed though...
Attached to frame. Trying to locate a heavy duty box to use has not been successful. Thinking about having a friend weld up a custom on to bolt on... I think I would prefer this, but it is also the one that seems to need the most prep/fab work.
Or in the p/u bed. Reluctant to do that since it sticks out some when tucked into the space by wheel well.

Also, it just occurred while typing, I still need to mount my truck bed tool box. I could put the 2nd battery in that...

Those electrical/battery experts... Does the 2nd battery have to match specs? I believe the type of battery has to match or is highly advisable. As in an AGM with another AGM... The Genesis kit is sized for a group 34. The specs are slightly different for a group 27 and group 34.

 

If you are going to mount a tool box, you really should install it in that. Make some space over on the driver side for it to make it easier to run the battery cables for yourself. If you have a buddy who can weld maybe have him build you a bracket of some sort the battery can sit in so you can properly secure it within the box. Consider a way to keep the battery covered so none of your tools bump into it and cause it to be damaged or arc between the posts.

A second battery does not need to match the size of your first battery, but it is advised to match the type (although you dont have to do this if you have the right type of voltage regulator). If you already have an agm, get another one of those, since they can be cycled pretty low as well. Make sure you use proper cable sizes and remember the further you run the cable the thicker you want it so you lose less current over the length.

Hope this helps

 

I will be switching to a lithium battery soon because costs are going down, you can use up to 80% of the battery (vs 50% for AGMs), and during that 80% the voltage is constant. With non-lithium batteries the voltage levels will creep down as it is being used.

Got my eye on this one, which has the same dimensions as my group 31 secondary AGM:

$280 LiTime 12V 100Ah Self-Heating LiFePO4 Lithium Battery with 100A BMS Low Temperature Protection, 1280W Load Power with 4000+ cycles and 10-Year Lifetime Perfect for RV Solar System Home Energy Storage

https://www.amazon.com/dp/B09BR4MYBV/?coliid=I10XFWLBHSD1KI&colid=1DIVQE7G9K3VU

 

I’d go with SOK. A little bit more but at least you can swap out the cells if one craps out on you but your bms is still good. The amp time and renogies are sealed and you’ll have a hard time getting it put back together once cracked open. Plus they have every feature like heat (for your winter rubicon trips), high cutoff etc etc. I’m debating up switching mine over if there’s a BF sale. Check out will prowse on YouTube. He’s reviewed almost every LifePO4 battery ever made

 

I like that kid, he's funny AF when he just laughs at the cheap stuff. He did a review and the SOK and AT are basically the same thing, same parts, which is why I'm looking at the AT.

 

Got it! I’ll have to go back and watch that one. Thanks for the tip

 

I like how excited he gets geeking out on this stuff.

Some of the guys on the RV forum I'm on have been using the Weize 100Ah Lithium based largely on Will Prowse reviews of it and nobody has anything bad to say about it.

I'm about to pull the trigger on 2 of them for my trailer. $350/ea on Amazon.

$198 Weize 12V 100Ah LiFePO4 Lithium Battery, Built-in Smart BMS, Low Temperature Protection Group 31 Deep Cycle Battery for Trolling Motor, RV, Solar, Marine, Camping and Off Grid Applications

https://www.amazon.com/dp/B09F2LLMY3

https://www.youtube.com/watch?v=-c6A1THDaeU&t=14s

 

I may pull the trigger on this for my kayak trolling motor battery.

 

I had a small xs power battery (almost mower sized) in my 08 as a back up to my system. I had 2 3k amps and a 4 channel. Only other thing was a big 3 done to the truck.

 

Check if it has an IP rating (water/dust resistance) since it’ll be near water - I haven’t been able to find it. That’s a deal breaker for me as my battery is exposed underneath the truck.

 

This is what I did as I have a Weatherguard chest mounted in the bed of my '07. I have an MTM "Ammo Crate" repurposed as a battery box that holds a 75 Ah AGM and a relay/fuse panel. it's bolted to the chest and bed and has venting. My battery is on the passenger side to help balance out some of the Tundra lean.

If I was starting 100% over or didn't have a chest, I'd look at a battery box under the bed of the truck. There are some pretty good voids in front of and behind the rear fenders and you can mount to the frame. I'd also be much more comfortable mounting a Li-Ion battery there vs inside the cab.

 

My first thought, and as many others have stated, is what a bad idea.

Why not dual battery under the hood where it's less of a hazard and route a protected/enclosed terminal block inside the cab?