Fuse block location question

[tacomasolar123]

Hey folks. New to the forum and first time posting. I'm looking to set up an aux battery for my tacoma. I've purchased a 206ah sok and have decided to take out a backseat and mount it behind the passengers seat in a fabricated battery box. The main load is going to be a dometic fridge that will also reside in the back seat, however I'd also like to run power to the bed of the truck, which has a shell and a sleeping platform. The main question I have is where is the best place to put a fuse block (blue sea). Most of my appliances will be in the bed, and will be low amperage. I've done an audit and come up with no more than 25 amps at a given time coming from the bed (fan, leds, seat heaters for bed, etc...). So, should I run a cable to the bed and have the fuse block be far away from the battery, or should I run the individual appliance cables into the cab? I'm using xt60 connectors on the appliances to be able to do quick disconnects. Just wondering if there is a best practice?

Since it's so low amperage, I've also thought about just running a single cable from a busbar in the bed to the fuse block in the cab and putting it on a single 30 amp fuse in the fuse block. This would allow me to fuse the mppt (thinking victron 20 amp mmpt for 200w of solar in series) in the fuseblock well. Anyway, I'd love to hear some thoughts about what is considered best practice.

Thanks,

Steve

 

[rmaddy]

It will be much simpler and cheaper if you minimize wire runs. Putting the fuse box in the bed means you don't need to run a pair of wires into the cab for each load that's in the bed. Run a single pair of wires from the cab to the fuse box in the bed and you're done. You don't want to have to run another pair of wires between the bed and cab months later because you decided to add something in the bed. Much easier to simply run to the fuse box in the bed. And to help with future proofing, use larger than needed wire to the fuse box. That will save a lot of work in the future if you add something and realize the original wire can't handle the amps or there is too much voltage drop. Assuming about 20 feet of wire round trip between the fuse box and battery/bus bars, 6AWG would be good for 25A-40A. 4AWG would be better if over 20 feet round trip. If under 15 feet round trip the 6AWG would be good up to 50A.

It's simple enough to fuse the charge controller separately without using the fuse box in the bed.

 

[tacomasolar123]

Thanks @rmaddy. That makes a lot of sense. I see that you also have the 206 soks. Do you happen to know if they have low voltage disconnect as part of their BMS? Or do you have to purchase a separate component?

 

[rmaddy]

The SOK does have LVD as part of its BMS.

See the following thread. The first post has the spec sheets for the SOK 12V 100Ah and 12V 206Ah batteries.

SOK LiFePO4 specs: 100Ah vs 206Ah

The SOK website lists basic specs for each of their batteries. But, apparently the only place you can currently download detailed spec sheets is the SOK Facebook Group. I've attached the spec sheets for their two original 12v batteries (100Ah and 206Ah). Specs sheets for their two newer...

diysolarforum.com

 

[rmaddy]

What year is your Taco? If it doesn't already have one, you should add a lock to the tailgate. I had a '15 with a topper and added a lock to the tailgate. It was setup to automatically lock/unlock along with the passenger door.

 

[tacomasolar123]

It's a 2021. Just got it and I'm building it out. The tailgate locks manually with the key, so it's not synced up with the button on the fob. I think I saw somewhere that they make kits that connect it to the rest of the doors, so I might invest in that at some point. Still have to figure out a way to lock the topper glass from the inside.

 

[rmaddy]

The manual tailgate lock is fine. My '15 didn't even have that.

Careful locking things from the inside. Plan for the worst. Imagine a fire starts from a short or something. You need to be able to open the topper and/or tailgate very quickly and get out. At least have a fire extinguisher in the bed by the tailgate. Does your topper have side windows that can be opened from the inside?

 

[tacomasolar123]

Thanks for all the good pointers. I'll grab a fire extinguisher for sure. And it does have windows that can be opened from the inside.