Best option for tapping into rear battery

[mikerorke]

What's the best option for making your own connections with the rear battery? When I took off the positive terminal cover, there appears to be an open terminal available (yellow arrow) - is that preferable to attaching directly to the terminal (red arrow)?

 

[mikerorke]

Quick update here. Went ahead and connected to the open terminal (yellow arrow above). According to the red terminal cover, this is a fused (200A) output. I added my own 40A breaker just to be extra safe. Compressor works great and much easier to access power through the upper door with the jack behind it.

 

[PixelMagic]

Thanks for posting this and for the clear pictures!

Do you have a link to the parts?

 

[Don]

A winch install Youtuber said that there was a current sensor on the battery positive. I presume in the fuse box. So wiring a high current device to the fuse block instead of the battery is probably correct. Toyota likely wants to engage the hybrid to 12V charge controller when high current load is sensed on that little battery.

I plan to do the same takeoff as Mike for my compressor and probably a rear receiver winch. Although with a bigger breaker if I use one.

 

[mikerorke]

A winch install Youtuber said that there was a current sensor on the battery positive. I presume in the fuse box. So wiring a high current device to the fuse block instead of the battery is probably correct. Toyota likely wants to engage the hybrid to 12V charge controller when high current load is sensed on that little battery.

I plan to do the same takeoff as Mike for my compressor and probably a rear receiver winch. Although with a bigger breaker if I use one.

It is interesting that they left a high current terminal totally open. I wonder if this is used for something on other versions of the vehicle or maybe shared with the GX550

 

[Don]

It is interesting that they left a high current terminal totally open. I wonder if this is used for something on other versions of the vehicle or maybe shared with the GX550

I hate to be wildly optimistic, but they may have considered that some crazy owner would modify the vehicle. Yes, even without written approval of senior Toyota engineering management.

But I do note that they did not include a nut. Probably as a silent head shake of disapproval.

 

[Ed1]

@mikerorke , what type of port did you wire? It's not really visible from that angle in the final photo.

 

[mikerorke]

Thanks for posting this and for the clear pictures!

Do you have a link to the parts?

4GA cable connecting battery positive to 40A breaker: Amazon.com
40A breaker: Amazon.com
6GA 'pigtail' with anderson plug: Amazon.com

 

[mikerorke]

@mikerorke , what type of port did you wire? It's not really visible from that angle in the final photo.

Its a standard 50A anderson plug - they are usually grey but also come in red. It also has a black dust cover on the end which makes it look odd. I cut the battery clips off my compressor power cable and wired them to an anderson too for easy hookup without having to remove the plastic tray to get to the battery panel

 

[Don]

A 2GA setup might be desirable if a winch on the receiver might be used. This setup would use more than a 40A breaker

Winch Power Cable | Quick Disconnect | 7 Ft

 

[mikerorke]

A 2GA setup might be desirable if a winch on the receiver might be used. This setup would use more than a 40A breaker

Winch Power Cable | Quick Disconnect | 7 Ft

Yeah - for a winch I think you want to connect directly to the battery like the Dissent Off-road folks did in their YouTube video. Sine my compressor claims to only draw 20A at most, the 40A breaker should be good.

 

[EOD Guy]

Quick update here. Went ahead and connected to the open terminal (yellow arrow above). According to the red terminal cover, this is a fused (200A) output. I added my own 40A breaker just to be extra safe. Compressor works great and much easier to access power through the upper door with the jack behind it.

Nice looking install!

I use those C/B a lot and would like to offer you a small piece of advice. Those little rubber caps tend to fall off, leaving the terminal exposed. I actually cut them off now. I use these from Amazon, hard to slip over the stud but will not accidently slip off either.

 

[mikerorke]

Nice looking install!

I use those C/B a lot and would like to offer you a small piece of advice. Those little rubber caps tend to fall off, leaving the terminal exposed. I actually cut them off now. I use these from Amazon, hard to slip over the stud but will not accidently slip off either.

View attachment 10087

Great advice - I will do that. Thanks!

 

[Don]

Yeah - for a winch I think you want to connect directly to the battery like the Dissent Off-road folks did in their YouTube video. Sine my compressor claims to only draw 20A at most, the 40A breaker should be good.

I don't think Dissent was comfortable about how to connect the winch. But you are right that even a smaller winch would pull more than 200 amps under high load.

the dissent winch wiring