Wiring up my AWD lifted Toyota Sienna - please tear apart my first ever wiring diagram before I burn it down

[carmensandiego]

Hi everyone,
I've been lurking for a while but this is my first post!
My boyfriend and I are building up our 2013 AWD Toyota Sienna. So far, we've installed a 3.5" lift, insulation and the subfloor. Now I've been put in charge of the electrical planning. I've never done any electrical work before, so tear apart this diagram before I burn our van down

Note: the diesel heater is intentionally bypassing the low voltage protection - the heater can melt down if the power is disconnected before it can complete it's 10 min cool down cycle.

I do have a couple questions:

1.) How do I size the ground wires? Same size as the corresponding positives?

2.) Should I be using a bus bar instead of attaching 3 wires directly to the battery terminals?

3.) Does anyone have recommendations for a good/cheap battery monitor?

Thank you!!

 

[HRTKD]

Positive and negative wires for the same device should be the same size.

Sizing wires is based on length, voltage and expected amps. Plug those three numbers into the calculator below to get the gauge you need. The goal is to have less than 3% drop.

Interactive Wire Size Calculator

Battery Chargers, Inverters, Solar Components, and Wiring Supplies for Boats, RVs, and Off-Grid Applications.

baymarinesupply.com

Ideally, for a tidy wiring arrangement, a set of common bus bars are recommended. The fuse on the positive wire from the battery will go between the battery and the positive bus bar.

I'm not a fan of using an ANL immediately downstream of the battery. A Class T fuse is a better fuse for that position.

I don't see a shunt in your diagram. How are you planning to know the state of charge of the battery? Good and cheap aren't always found in the same product. There are a few members using a cheap hall monitor. I use a Victron BMV-712, but that's more expensive than you're looking for.

The direct connection to the battery from the heater is unusual, but I understand why you're doing that. The problem with that connection method is that it bypasses your battery monitor which will confuse it into thinking it has more Ah remaining than it really does. You're not going to bypass the low voltage protection found in the BMS that is built into the battery. So you may not get the end result you're looking for unless the Victron Voltage Protect is set fairly high.

No solar panels?

 

[carmensandiego]

After some further review, this is the final wiring scheme. All wires to the left of the fuse box are 2AWG and all loads to the right are 12AWG. The longest stretch is from the car starter battery to the house battery ~22ft.

The Renogy charger give me the option to add solar panels to the roof of my van at a later time if I decide I want to expand, but I don't currently have a fridge or many high consumption devices.

I'm undecided on what to use for a battery monitor. I'm thinking of going with the Renogy battery monitor which plugs into the Renogy charger with a RS485 communication port but I haven't fully committed to it yet. My battery can also connect to my phone via Bluetooth which lets me monitor the health of the battery and each of the 4 cells.

 

[Sea]

View attachment 48253

After some further review, this is the final wiring scheme. All wires to the left of the fuse box are 2AWG and all loads to the right are 12AWG. The longest stretch is from the car starter battery to the house battery ~22ft.

The Renogy charger give me the option to add solar panels to the roof of my van at a later time if I decide I want to expand, but I don't currently have a fridge or many high consumption devices.

I'm undecided on what to use for a battery monitor. I'm thinking of going with the Renogy battery monitor which plugs into the Renogy charger with a RS485 communication port but I haven't fully committed to it yet. My battery can also connect to my phone via Bluetooth which lets me monitor the health of the battery and each of the 4 cells.

So @carmensandiago, did you get the build done? How is it working? Wondering b/c I have a 2017 Sienna hoping to put a house battery in.