Auxiliary battery wiring

[arod2051]

I have a 2014 GX460 premium

I want to put an auxiliary LiFePO4 battery in the rear cargo area. I’ve read a few posts and watched some 4Runner vids on running wire to the rear cargo area from starter battery <-> inline fuse <-> BCDC <-> aux batt.

I’ve also read a few posts about the 120V (100w) inverter and it’s utility, or lack thereof.

Questions:
I was wondering if I can cut the 12v wiring to the rear inverter and connect to a BCDC <-> aux batt <-> fuse block -> new inverter.
Additionally, I have the premium model. The luxury model has the power 3rd row seats. Is the wiring harness the same between luxury and premium and does that mean I can use those unconnected lines for an aux power solution?

Goal:
1) less wiring, 6awg or 8awg
2) I can replace the limited utility inverter with one of my choice running from an aux battery
3) Add more 12v receptacles

Drawbacks and concerns:
- Is the current cable feeding the inverter capable enough to feed the a 1225D BCDC? If I read the fuse block diagram correctly, it is fused at 15A, which is cutting it really close.
- I would have to full time carry an aux battery for those AC and DC ports to be live. But if I can fit a battery under the wing of a drawer system, I would do this anyway.



Edit: corrected info on fuse for inverter, added question about power seats for luxury model.

 

[giovanni]

I can't answer whether the Premium has the wiring for 3rd row, but I can provide some input on using that 3rd row power for aux battery purposes.

1. It is always live, so you need to think about how that behaves. In my case, I set my DCDC to shut off when the supply battery voltage drops below some threshold. I watched the voltage with the car running / charging and with it shut off and the Renogy DCDC charger that I bought just happened to shut off when the engine shuts off so this works for me without worrying about draining the start battery.

2. The power seat circuits are individually fused (left, right) at 30A each. However, the wire size feeding them is substantially less than recommended for continuous, low voltage drop 30A use. So I connected the two circuits in parallel and used that combined feed to power my DCDC 30A charger. I carefully watched for overheating wiring and have not noticed any.

3. I have a 1000W inverter that I put 100A Anderson connectors on, so I can plug it in the aux battery side of my DCDC charger, so it only pulls from the LiFePO4 aux battery. Works great.

 

[arod2051]

I can't answer whether the Premium has the wiring for 3rd row, but I can provide some input on using that 3rd row power for aux battery purposes.

1. It is always live, so you need to think about how that behaves. In my case, I set my DCDC to shut off when the supply battery voltage drops below some threshold. I watched the voltage with the car running / charging and with it shut off and the Renogy DCDC charger that I bought just happened to shut off when the engine shuts off so this works for me without worrying about draining the start battery.

2. The power seat circuits are individually fused (left, right) at 30A each. However, the wire size feeding them is substantially less than recommended for continuous, low voltage drop 30A use. So I connected the two circuits in parallel and used that combined feed to power my DCDC 30A charger. I carefully watched for overheating wiring and have not noticed any.

3. I have a 1000W inverter that I put 100A Anderson connectors on, so I can plug it in the aux battery side of my DCDC charger, so it only pulls from the LiFePO4 aux battery. Works great.

Giovanni,

I think it was your post that made me think of alternate wiring options. I know you made a change already, but did you take pics of the 3rd row seating power wiring harness? I am going to remove mine and remove the side plastic to see what options I have available.

 

[giovanni]

Just went out and took a couple of pictures of my harness tie in - this was just a "see if it works" version, so will clean it up and route the wiring better now that I know it does.

The seats each have one connector going to them. All I did was use a multimeter to figure out which wire was constant hot, cut it upstream of the connector and splice in my blue wire. The blue wire connects both left and right 12v wires, and to my Anderson connector. I have my aux battery, for now, in a Pelican case that I can move around as needed.

The attached pic of the Pelican case shows only one battery, but I have 2 now. I will, in the future, put one of those batteries in the truck and have it always plugged in, and the other in a case that I can take out.

My reason for doing it this way is that I wanted to charge my aux batteries while doing "day drives" while camping, and then be able to recharge or add to my camper battery capacity at camp with no unnecessary engine or generator run time.

 

[THEOZMAN]

For Any one that will attempt to use the 3rd row seat power for accessories. I am starting to make connectors that allow you to have power leads without cutting and splicing into the OEM wiring harness. I will be creating a post soon about it.

 

[giovanni]

I'm interested and will take 2!

 

[r2m]

Okay, so this may be more than you want, but if you go to my build thread: Builds - R2M 2013 GX460 Overland Build - https://forum.ih8mud.com/threads/r2m-2013-gx460-overland-build.1104719/page-2
Starting at post #28, I went a little different route. I have both my batteries in the factory battery tray and ran 1/0 AWG wire to the rear for a 3000 watt pure sine inverter and power panel with 2 USB 5 VDC ports and a 12 VDC socket with volt meter.
So your first question is, "Why a 3000 watt inverter???"
When we go camping, I like to cut a split my own wood. I used to carry around a 16" bar gas/oil 2 stroke chainsaw. I just got tired of the smell, leaks, having to do the "oil-gas" mix all the time and the constant pull starts when it's cold. Now I have a great little electric chainsaw, I always keep a 100' of heavy gauge extension cord because I'll never haul firewood more than that to my rig in the woods AND... Just pull the trigger and it will ALWAYS start!!
Also, living down here in So. Cal. we occasionally get power outages, either wind storm, over use during heat waves, fires, whatever. With this inverter, I can just about power my entire home! Or at least keep both the fridges (kitchen and garage) running and still be able to watch TV with a light on until power comes back on!

 

[arod2051]

For Any one that will attempt to use the 3rd row seat power for accessories. I am starting to make connectors that allow you to have power leads without cutting and splicing into the OEM wiring harness. I will be creating a post soon about it.

Do you have PayPal?

JK, really interested to see this.

But, seriously, will this work for Standard and Premium models that don't actually have powered 3rd row seats?

If 'yes', what is your PayPal?

 

[giovanni]

Okay, so this may be more than you want, but if you go to my build thread: Builds - R2M 2013 GX460 Overland Build - https://forum.ih8mud.com/threads/r2m-2013-gx460-overland-build.1104719/page-2
Starting at post #28, I went a little different route. I have both my batteries in the factory battery tray and ran 1/0 AWG wire to the rear for a 3000 watt pure sine inverter and power panel with 2 USB 5 VDC ports and a 12 VDC socket with volt meter.
So your first question is, "Why a 3000 watt inverter???"
When we go camping, I like to cut a split my own wood. I used to carry around a 16" bar gas/oil 2 stroke chainsaw. I just got tired of the smell, leaks, having to do the "oil-gas" mix all the time and the constant pull starts when it's cold. Now I have a great little electric chainsaw, I always keep a 100' of heavy gauge extension cord because I'll never haul firewood more than that to my rig in the woods AND... Just pull the trigger and it will ALWAYS start!!
Also, living down here in So. Cal. we occasionally get power outages, either wind storm, over use during heat waves, fires, whatever. With this inverter, I can just about power my entire home! Or at least keep both the fridges (kitchen and garage) running and still be able to watch TV with a light on until power comes back on!

I had the same scenario with the chainsaw ... but my solution is a dual 18V battery chainsaw. I can cut plenty to clear a roadway or build a fire, and I carry a charger with me.

 

[arod2051]

Just went out and took a couple of pictures of my harness tie in - this was just a "see if it works" version, so will clean it up and route the wiring better now that I know it does.

The seats each have one connector going to them. All I did was use a multimeter to figure out which wire was constant hot, cut it upstream of the connector and splice in my blue wire. The blue wire connects both left and right 12v wires, and to my Anderson connector. I have my aux battery, for now, in a Pelican case that I can move around as needed.

The attached pic of the Pelican case shows only one battery, but I have 2 now. I will, in the future, put one of those batteries in the truck and have it always plugged in, and the other in a case that I can take out.

My reason for doing it this way is that I wanted to charge my aux batteries while doing "day drives" while camping, and then be able to recharge or add to my camper battery capacity at camp with no unnecessary engine or generator run time.

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What a simply superb response to a request. You actually went out to take a pic. This I very helpful. I would have started searching near the front side of the cargo area.

 

[THEOZMAN]

Do you have PayPal?

JK, really interested to see this.

But, seriously, will this work for Standard and Premium models that don't actually have powered 3rd row seats?

If 'yes', what is your PayPal?

I am not sure if the ones without the powered seats have the wiring and I would assume not. If you have a powered ones these will work.

 

[THEOZMAN]

I'm interested and will take 2!

Cool. I will PM you!

 

[arod2051]

I am not sure if the ones without the powered seats have the wiring and I would assume not. If you have a powered ones these will work.

Theo,

I think you are right. I went ahead and removed my third row seats and removed the driver‘s side rear plastic. This is what I found.

the top connector, right below the bright red thing, looks like a ground bank (with a really cheesy ground connection.
The 2nd and 3rd connector looks connected to nothing and it hanging onto a bracket. I’ll undo it tomorrow when there is light out. But they don’t look like the connector that giovanni posted earlier.

A closer shot

 

[THEOZMAN]

If the connectors exist, they would be on the floor of the trunk kind of by the big grommet. It would be a 25 pin connector with 4 of those wires thicker than the rest.

 

[Acrad]

If it is determined power connectors are "not present" on non-power folding 3rd row models this mod would only be available on:

- All 2010-2013 models

- '14-'21 Luxury Models

- '21 Premium model w/Premium Plus package

 

[arod2051]

If the connectors exist, they would be on the floor of the trunk kind of by the big grommet. It would be a 25 pin connector with 4 of those wires thicker than the rest.

Indeed, I believe the Premium model, and presumably base model, does not have the fun connector we need.

 

[THEOZMAN]

Indeed, I believe the Premium model, and presumably base model, does not have the fun connector we need.

View attachment 2571360

Thanks you for Checking!

 

[arod2051]

For completeness, I took off the side plastic on the passenger's side. I was hoping the input to the inverter driving the 120V outlet was easy to find and I can make use of that.

Suffice it to say, it's not easy to find. I spent more time removing plastic than it would have taken me to run wire from the starter batt to the location of the BCDC. Lol.

Now, I need to solve the dilemma of 8awg vs 6awg. I am going to run the wire down the channel where the step trim panels are. I am worried about space. I am going to run a current return path down for gnd as well. I feel chassis gnd is pretty good on these 460's, but if I can fit it, I'd rather have 8awg+return path than 6awg+local chassis gnd. Or, the best would be 6awg+return path. Need to test fit.

Any experience out there to help the inexperienced on this?

 

[THEOZMAN]

For completeness, I took off the side plastic on the passenger's side. I was hoping the input to the inverter driving the 120V outlet was easy to find and I can make use of that.

Suffice it to say, it's not easy to find. I spent more time removing plastic than it would have taken me to run wire from the starter batt to the location of the BCDC. Lol.

Now, I need to solve the dilemma of 8awg vs 6awg. I am going to run the wire down the channel where the step trim panels are. I am worried about space. I am going to run a current return path down for gnd as well. I feel chassis gnd is pretty good on these 460's, but if I can fit it, I'd rather have 8awg+return path than 6awg+local chassis gnd. Or, the best would be 6awg+return path. Need to test fit.

Any experience out there to help the inexperienced on this?


View attachment 2571910

I would run a 4 gauge wire from the get go. with 4 gauge you can add 1000k inverter in the future and in general just future proof anything you may throw at it. I looked into utilizing the inverter wires for power but the size was too small to be anything useful.

 

[arod2051]

I would run a 4 gauge wire from the get go. with 4 gauge you can add 1000k inverter in the future and in general just future proof anything you may throw at it. I looked into utilizing the inverter wires for power but the size was too small to be anything useful.

Theozman,

I am connecting the starter batt to a BCDC 1225D. From there, the AUX batt that it charges will have 4awg wire to a fuse block, where I expect to power the world!

Do you think I still need 4awg to the BCDC? It feels like there are already limiting nodes beyond the wire.

Although, the outside diameter of 4awg is not that much bigger than 6awg. I have 4awg lying around. Let me check the fit.