Need help with wiring options for 3000W inverter
 

Hey everyone. Happy new year to y'all!

I'm finally getting around to adding several AC powering options to my 2008 Ltd. V8.

I plan to add a couple AC sockets to the passenger compartment, mostly for laptops. And I plan to add 4 sockets to the cargo/trunk in the back. I'm a photographer, and I plan to use 2 of them for full-time battery chargers, and the other 2 for gear while camping or other things needed occasionally.

I have not yet picked out an inverter, but I know I'll go with a 3000W (constant), pure sine vice modified, with built-in overload, over-heating, over-and-under voltage, and fault protection.

The broad plan here -- based on my research, not any real knowledge of electricity -- is to install the inverter along with three 200-amp fuse block/fuse kits (to allow one for a second battery and one for a battery isolator). (Yes, I'll have an electrician work closely with me on the install.) The extra battery would be a 100Ah VRLA AGM to help maintain voltage if I'm running heavier than usual loads, and to reduce the risk of overheating. The isolation relay would be to help prevent drainage of the main battery.


2 Questions:

1. Any thoughts on the best place to install the second battery? I don't see a lot of room even in the engine compartment. Where else have people put them?

2. I am not interested in having cords and things around the car running to wherever the inverter is installed. I want to install an AC socket directly into the door or cargo panels. What is the best way -- within electrical codes and without compromising anything in the truck -- to accomplish this?

Maybe something like this for the outlets? My only concern would be shielding the connections on the back but that's not hard.

https://www.amazon.com/uxcell-Panel-.../dp/B008X0WM5U

I'd look to see what you can buy from a marine or aviation supplier. Figure if it's good enough to run power in a boat or plane, it'll hold up in an SUV.

I know there were a few other posts about auxiliary batteries but this was the bracket I found on a quick google search.

2003 - 2009 Toyota 4Runner Auxiliary Battery Tray – Off-Grid Engineering

I'm sure you could make something similar for less, or you could go to your local pick-n-pull junkyard and walk around to find a car with a nice battery tray/battery box. I've used other vehicles OEM parts (battery cables, fuse blocks, etc) more than I'd like to admit but the price is right, the quality is there, and there is plenty of variation between manufacturers/models.

Here's one more I stumbled upon that might work.

2005 - 2015 Toyota Tacoma Dual Battery Tray

Here's an alternative suggestion. Rather than spending the bucks on a big inverter/battery setup, perhaps consider some DC/DC power supplies for the items you have. Here's a link to a supplier for about every laptop out there:

High Reliability Auto to Laptop DC/DC Converter for all computer models

Inverters are terribly inefficient and expensive. Changing that 12VDC all the way up to 110VAC then plugging in the laptop supply (knocks it back down to about 19VDC) wastes a lot of energy in the process. Having this universal power supply too means you can easily jump to your friend's vehicle rather than having a specialized power system in your rig alone.

Sounds like you have other loads that will require 110VAC but for most personal electronics these days (laptops, tablets, phones, cameras, etc) there's a low-voltage equivalent charger that will do the trick.

With that said....I run my fridge in the cargo area off an AGM battery wired in parallel through an isolation relay to the main starter battery. Only when the truck is "ON" are the two connected to prevent my "house" battery from ever draining my starter battery. This is accomplished with some 6awg cable and anderson powerpole connectors along with several fuse holders and associated blocks and such. Luckily...the fridge runs on 110VAC by default. When I'm at home or in a campground with power, I plug in the available power source. This runs the fridge and a charger that tops off the rear AGM battery only. There are tons of build threads where people have all kinds of intricate electrical setups. Take your pick.

My next little project will be to add some USB ports, a cigarette lighter socket, and voltmeter panel to my setup in the rear so I can charge my phones and other gear from the house battery when the vehicle is off. The wiring is pretty simple but I'm having a hard time figuring out where I want to put the ports so they're accessible but not in the way or likely to get damaged. I added a pair of USB charging ports to the center console about a year ago. They work great but that area between the shifter and armrest seems to be a less than optimum place for loose cables to be dangling. So far I've broken one USB cable but luckily it appears to not have damaged the ports.

Good luck

This would be a pretty rad piece to use for exactly that purpose.

Blue Sea/ OGE Auxiliary Power Outlet System with Voltmeter – Off-Grid Engineering

Just found it while perusing their website after seeing the dual battery tray.

https://cdn.shopify.com/s/files/1/12...G?v=1541030519

3000 watts / 12 volts = 250 amps
Estimated wire size = 1/0 AWG

That’s a lot of inverter to have on a 12v system… and none of that takes into account surge or peak loads.

Laptop, camera and equipment charging can often times be taken care of with a much smaller inverter. Larger the inverter, higher the idle load consumption, and generally inefficient with smaller loads.

Having done setups like this many times, I would start by identifying how much power you actually NEED so you can size the inverter correctly.

3000 watts is a lot of demand for a 12 volts system… if you want to run something that large, it makes a lot more sense moving up to a 24v or 48v system. Its more efficient, smaller wire sizes, and charging can be taken care of using a DC-DC. For example 3000 watts / 48 volts = 62.5 amps. You can use a very manageable 8 AWG size cable to wire the entire thing. Not to mention, you will probably find more options and better pricing on 24, 36, and 48v 3k watt inverters when compared to 12v.

Inverting to AC is my last resort... waste of energy going from DC to AC and the back to DC to charge your portable devices. You might as well just get a DC-DC step down converter and charge your gear directly off a DC source.

That's more or less what I had in mind too, but I was leaning towards using a few of these:

West Marine Blue Sea Systems Dual 120v AC Outlets

Bt my question is more about installing it. Whatever outlets I use, how should I wire them to the inverter? What is an acceptable way of wiring them? i.e., safe, within the electrical code, and not compromising to anything else in the vehicle

I prefer clean installs, OEM looks, no visible wires or power strips, and direct-to-source wiring (thus no tapping into existing lines, hence the plan to wire straight to the battery). So I'll take the time and spend the money to do it "right" rather than hacky. But while I've got an idea now of how to wire the inverter and fuses and the extra battery, I'm not sure how to wire the outlets I'll put into the paneling to the inverter itself.


dt

I like it! I was thinking about voltmeter options too, so that might be a good one to try.

Ill give you a bit of a head start when it comes to inverter selection...

I have a 12 volt 500 watt version installed in my Silverado specifically for things like you mentioned. Even 500 is more than I need, I could have went with the 375 for my use case.

Victron VE Direct Inverters

These are excellent, pure sine, and efficient small inverters. I have plans to install a 24v version in my 4Runner which is powered by a custom made 24v lithium battery bank.

Maybe my numbers were wrong running up the totals. What's your estimate of the maximum constant power needed from an inverter for the following --- noting that I don't want to run the system always at the limits. I'd like some "breathing room" in the power supply.

(Note I already have a full-time hardwired power line for driver's cell phone. It taps into the cig lighter line, and has the constant power mod. I have excluded that device from the following)

These are the kinds of devices I was thinking of.

1. Up to two 17" laptops (90 watts each) plus 4 tablets and/or phones, all plugged in for simultaneous use by passengers
2. Winch (don't have one yet - but need to plan for adding one soonish)
3. On-board ARB air compressor
4. Four Canon LC-E6 chargers (each one spec'd to 100 to 240 VAC, 50 / 60 Hz at 115 to 210 mA). These will need to run even with the car off.
5. Canon 1D or 5D camera, plugged in for constant power supply while shooting in cold, arctic, or long-exposure conditions where battery use would deplete rapidly. * I have both AC and DC options for the camera. Must be powered at all times.
4. Portable heater (1500 watts).
5. Exterior lighting -- all OEM lighting replaced with LED, plus an LED light bar, four spot & accessory LED lights, and LED fog lights front and rear.
6. Iridium 9555 satellite phone vehicle docking station/charger (10-32 Volt DC / 12 VDC). Must be powered at all times.


One other question -- I need to replace my primary battery. It's a POS aftermarket battery I bought in an emergency outside Tahoe when the OEM battery finally went out. 3 years later it's already failing. It's gotta go.

Can I simplify this whole setup by replacing the primary battery with a single large, heavy duty, probably marine-grade battery? Or is a dual battery with isolator still the preferred option here?

At what point do I need to worry about overtaxing my alternator?

3000 watts is a crap ton of power, even if you only used half of it at 1500 watts, that is still 125 amps DC continuous. You are going to be in immediate need of a new high output alternator. Stock, even with the engine running at high idle, you will be using more power than you are making with the stock alternator.

An inverter that big might use an amp just sitting there doing nothing. Just leaving it on with nothing connected to it you could kill a battery in 2 days. This is why I opt for small inverters, the idle load is very low if you buy decent stuff.

Even you tried to run that heater using a top-of-the-line deep cycle battery, say 100Ah deep cycle (50Ah usable), you would get at most 20-25 min of runtime before you consider it 0% state of charge, taking much longer to recharge it. Pushing it any more you are either going to blow fuses or damage the battery. It’s not a realistic load for a 12v car setup without a serious battery bank. Higher voltages 24v min, 48v preferred.

Ditch the 1500 watt heater… buy a gas powered indoor safe Mr. Heater unit. Its cost effective. Even with a high output alternator, running an engine for power makes for a terrible inefficient generator. If you want to use gas, buy a Honda or Yamaha 2000 watt inverter generator for camp use. I have one of those too.

Many of the other items like a winch, air compressor, sat coms, and lighting are all direct DC loads. Nothing to do with the inverter. The rest of it could be powered with a 500 watt Victron without a problem.

Take a look at this thread, looks like some good options in there that would work for your application as well! I tagged you but just wanted to make sure!

Ross4runner build thread (aka Sparky)

3000W is doable I guess with a 300A alternator and a Big Three wiring upgrade. I'm guessing that would have to be done as a start, then you slap in the fuse blocks and aux battery.

Where to install that physically large inverter, maybe 16x10x6 dimensions?

This. A 5-600W inverter will run everything besides the heater just fine.

It can be done, and what you said is a very minimum requirement to make it happen. Most alternators don’t hit their output ratings at idle either. You will most likely need to install a high idle switch like seen in diesel and tow trucks.

Also agree with the size thing, its physically large if talking about a REAL 3k watt inverters, not the junk stuff which is often times advertise the peak rating.