Build Easy Auxiliary Lithium Battery for your Crawler

I posted the this is my 304YOTA Build thread as well.

Long story short, my girlfriend is deathly allergic to bee stings, like she’s been told she could have 15-30min to get to a hospital allergic. It got me thinking about communication on the trail outside of Ham. After installing Starlink on my Toyhauler, I figured having a Mini Starlink on a crawler would be a good idea. But how to power it and not drain the starting battery. I’m not a fan of dual LA batteries, and lithium technology has progressed quite a bit, and come down in price.

I have a LiTime 100ah house battery in my Toyhauler that works perfect, so I decided to pick up one of their more advanced Group 24 100ah battery with Bluetooth and Self Heating. The Bluetooth allows for instant monitoring of the battery on you cell phone, so no shunt or Bluetooth module etc. the Heating allows the battery to self heat so that it can charge in below freezing temperatures.

I also picked up their new 40amp DC-DC Charger / Solar Controller, and an AuxBeam Switch Panel to control the accessories.

The DC-DC charger is a very simple hook up. It has 2 inputs and 1 output, all connected with Anderson Connectors. It self activates and switches between Solar or DC, and isolates the Starting Battery, and has a function where it can back charge the Starting Battery if it gets depleted.



I wanted everything to be easily accessible, So I decided to mount everything behind the Passenger seat of my 83’ Pickup. First I laid everything out, then started drilling and cutting.




The back I made a large opening to allow the charger better cooling. The slot allows for the wiring to enter the switch panel from the back.


I used 1/4” RivNuts and 1/2” spacers to mount the panel.


Then made up my 8awg cables and mounted everything up.






Set Battery Type, and the Charger handles the rest from there. No on/off switch needed. When it senses the alternator it switches from solar. If there is no solar it puts itself on standby when the vehicle is not running.

My original plan was to mount the battery under the bed, but I’m glad I decided to mount it in the front of the bed.

A simple battery box attached to the bed with 4 1/4” RivNuts and a lashing strap held the battery firmly in place.



I surrounded the battery, top, bottom and sides with heat shielding. Power and Charge Wires come up through the bed.


For the Starlink mount I went with 1 1/2” Ram Ball mounts. Total for the 3 pieces was pretty expensive, about $100, but I didn’t see any better options. The mount that clips to the Starlink fits it very secure, no fear of it popping off. The extension arm allows for easy positioning of the dish when in camp.




Side not, the Starlink mini has an internal router, so the only thing coming off of it is the 12v 18ga power. Friends said they could connect well over 150’ away.

I also hooked up my ARB Fridge that I bought and never used. The fridge is awesome, I won’t be going back to a cooler.




The end goal is to also have the Stereo and Rock Lights hooked up to it so I can use them non stop and not run down the starting battery.



The app makes for easily monitory the battery. My truck sat Friday night to Sunday morning without starting, and with Starlink running non stop and the fridge set to 24°, the battery only dropped to 48%. With the 4amp charger, it only took about 1 1/2 hours to recharge.

Here is a view of the app screen.

Nice work on the install and wiring.

but I don't see a subwoofer.

I use a small motorcycle battery as an isolated battery setup. cheap smart isolator. Runs my high power camping auto system for a long time, and all the lights and whatnot.

rattle_snake said:

Nice work on the install and wiring.

but I don't see a subwoofer.

I use a small motorcycle battery as an isolated battery setup. cheap smart isolator. Runs my high power camping auto system for a long time, and all the lights and whatnot.

Click to expand...

Oh there’s a sub lol, 2 8’s all Bluetooth.