DIY Camper Electrical Build (feedback wanted)

Hey folks,

I have been living/camping out of my Tacoma seasonally for the past few summers and fall and it is time to upgrade the power system.

I decided to start with a system that runs off my alternator with the ability to add solar later if needed. Here is a crude drawing of what I plan to do. I would love to hear people's thoughts and feedback and if I am missing anything major. This is probably a very simple task but this is something I haven't done before.


I plan to post photos of the build and updates on how it is working!

Thanks,
Steven
2010 Tacoma V6
6 Speed Manual

 

If you’re running auxiliary circuits you might want to read this OP, probably the best guide of its type. https://www.tacomaworld.com/threads/diy-build-and-install-a-bussmann-rtmr-fuse-relay-block.399454/
Not my cup o tea but there are also threads on adding solar as well as a second battery.

 

I have a run that long in my truck (~18') I used expensive but efficient 00 gauge wire. IIRC there would be a 3% drop over that length with 00 gage at 13 volts.

 

Wow that is quite the in-depth post. thanks! definitely some good bits of info I will use.

Wow 00 that is a beefy cable, I will have to do some more research. I am planning on using 4awg currently but I definitely had concerns with the length of the cable. any links to info on cable efficiency?

-Steven

 

Voltage drop depends on current not voltage. Ohms per foot times feet times current. 18’ of 00awg cable at .0779 ohms per thousand feet has a resistance of .0014 ohms. The voltage drop at 100A would only be .14V, barely 1% of 13V. Good for a winch connected to the battery but seems excessive for anything powered by a battery. To get to 3%(.39V) you’d have to be drawing closer to 300A. That’s a fair amount of money and weight penalty(~7lbs of copper). If 3% drop at 100A is your max you’d be about there with 3 or 4 awg(.19 or 24 ohms per thousand feet). Up to you though.
source
https://www.powerstream.com/Wire_Size.htm

 

Since having both batteries in the back of my cab, I looked at how could I ensure that I would be getting the little to no voltage drop between my winch and batteries and between my alternator and batteries. It was nearly 11 years ago so I have no idea of what my assumptions were at the time, I just knew I wanted a efficient path for electrons to zip through. I do think the breakers on either end of it are 200 amp).

I remember something like this:

200 amps


150 amps

 

That makes more sense to include the round trip for the voltage drop.