Can you guys look over my plans for hardwiring a power inverter?

[Andrew Clope]

I've never set a car up for chasing, but would like to set my truck up and maybe go out a couple times this year and just kind of poke around w my wife, as she's interested as well. I've got a 2013 F-150 and first was wanting to get a power inverter installed. Will be powering one laptop, a few cell phones, camera batteries, maybe a few more things if you guys have suggestions that I'm not considering?

I was looking at either the Whistler or Cobra 800 watt (I think that would be enough). Now, I've wired up car audio before, and I don't see why wiring up an inverter would be any different than an amp. 4 ga from the battery (fused 80 amp I think for 4 ga) to the inverter, and then 4 ga to a seatbelt bolt, or seat mounting bolt.

Is that all that I would realistically need? And would that serve the purpose of what I'd need out of it? Are there any other saftey considerations that I'm not thinking of?

Thanks for the responses, I'm just unfamiliar with inverters and am not sure if they are going to be any different than normal car audio. Also, will 800 watt be okay for the stock charging system?

Thanks!

 

[Dan Robinson]

I used a 750 watt hardwired inverter for 9 years with no issues. I have a 1200 watt one now. It's pretty straightforward, use heavy gauge wire and fuse it at the battery. I'd make sure your inverter is rated well over the load you plan to use regularly, as it will last longer. 800w should be fine. I built a main 12v busbar/terminal strip in the trunk that the inverter is just one part of. I did this because I need the ability to connect other 12v items to the circuit (dashcams, WxWorx, etc). My circuit is fused at the battery and again at the trunk busbar. I have a main power switch for the circuit on the dash.

The problem I ran into with hardwiring is forgetting to turn off the circuit when parking for a long time. I solved this issue with wiring in a buzzer alarm to a relay connected to the ignition-on circuit that powers the cigarette lighters. That setup is outlined in this thread: http://www.stormtrack.org/forum/showthread.php?30112-Battery-drain-defenses

 

[John Fertsch]

Could geta "Priority Start" from galls.com #UP007

 

[Andrew Clope]

Can you define "parking for a long time?"

 

[Andrew Clope]

Okay, so I went with a Whistler PRO 1200W inverter. The run I "generously" measured is 15' from battery, to where it will be mounted. By "generously" I mean that it will be no longer that this. Do you guys think that 4 ga wire will be adequate? Or should I go with 2? Also, what size fuse? The calculator I found says to run 150 amp fuse (sounds like a little overkill, and I'd rather have the fuse pop before the wire melts obviously).

 

[Dan Robinson]

Parking to eat dinner, sit for an hour waiting for initiation, or at the hotel at night. The larger inverters will drain your battery fast if you leave them running when the engine is off. The buzzer is my reminder to turn the circuit off - since installing it, I've never had a drained battery incident. Prior to that, I had to make many embarrassing requests for jumps.

 

[Andrew Clope]

I gotcha Dan thanks, just didn't know the timeframe. It looks like the one I purchased does have a shutoff (maybe they all do).

 

[Justin Wilcox]

Im in the same boat kind of. I bought a 400 watt inverter but never wired one. Yet I know practically everything about car audio. Right now I have 0 ga from my batt to a distribution block in the back. Then two runs of 4 ga, one going to a 4 channel amp and the other is free since I removed the other amp. Im wondering if I can just connect the free 4 ga run and the ground to the inverter from the distro block and mount it in the back. Does anyone see anything wrong with doing that?

 

[Rob Herman]

You might also want to consider fusing BOTH the + and - leads to the battery. That's what I found out when I Googled the topic.

 

[Tyler Allison]

I run two wires to the inverter from the battery. Off the positive _and_ negative sides. And I put fuses on both sides as close to the battery as possible. You don't want the wires in the cabin melting...you want the wires under the hood melting.

 

[Jeff Snyder]

Fusing the positive cable/wire is most important, IMO, since a short to ground (e.g., something on the vehicle's body pinches the positive wire through the insulation) will cause very high current draw and could easily overheat/melt/ignite the wire. A mishap with the negative wire (as in something metal on the car rubbing or piercing the insulation and contacting the wire) is likely to be less potentially-significant since your vehicle's body is grounded to the negative terminal of the battery, which means you'd essentially just be adding another ground point. In any case, it's very important to put a properly-sized fuse as close to the battery as possible to reduce the possibility of shorting the wire between the positive terminal and the vehicle's body (or anything connected by a conducting material to the vehicle's body and therefore to the battery's negative terminal). If you put the fuse in vehicle cabin, the run of wire between the battery and the cabin is not fused, which means an electrical short could end up starting a fire. I think the fuses on my cables that connect to the battery are fused within 18 inches of the battery. This assumes that your individual devices are fused themselves, so you're putting in fuses here to protect to the cables/wires and not the devices connected to those cables. Every inverter I've had (only been 3) has had a built-in fuse intended to protect the inverter itself, so the fuses I'd put in-line on the cables would be to protect the cables themselves.

I would suggest upgrading the wiring under the hood, at least the cable between the negative terminal of the battery and the vehicle (I think my car was grounded by a relatively high-gauge wire with a terrible connection).

I always put larger cable in than will ever be necessary for a given load because I only want to do the installation once (in my case, it usually requires removing much of the dash, removing seats and carpet, etc.) and the cost is usually limited compared to all of the other costs associated with chasing. I think I have 2 awg cable from the engine compartment to the trunk, where I have a fused power distribution block that has smaller gauge wires (each fused appropriately for the load and wire size) connecting individual items such as the inverter.

 

[Andrew Clope]

I have a couple questions now that I've run everything. I've got a Whistler 1200 watt inverter. I ran 4 gauge wire from the batt + (fused w 150 amp fuse 6" from battery) to under the rear seats to the + lug on the inverter. I then ran 4 gauge wire 16" away where I took a die grinder and ground the paint under the carpet down to bare metal. This is where I grounded the inverter. I also grounded the small case ground for the inverter here as well.

First off, is this safe? I've seen some people on this forum say that you should NOT run the ground all the way back to the battery, and others are saying that I should. Which is correct?

Also, when I first started the inverter up with the switch, it turned on displayed 14.5v from the battery and 0000 watts coming out (since nothing was plugged in). I plugged my laptop into it, and nothing. Plugged my iPhone into it, nothing. Then I removed the AC adapter end on the iphone charger cable and plugged the USB end into the USB charger on the interver, this worked and began charging the phone. When I re-installed the adapter and tried plugging it into the inverter, it wouldn't charge. I sent it back and asked for a replacement as it appeared as though the outlets were DOA.

Do you guys have any ideas?

 

[Jason Russell]

Should have stuck a multimeter in it and tested voltage.

Also, Apple 120v chargers don't work well (or at all) with modified sine inverters. Other brands of power adapter also have issues with modified sine. If it works but gets really warm, you're overworking the adapter circuitry that filters line noise to the laptop.

Whistler inverters can be hit or miss, but you should get a red warning light should anything be wrong. Generally you're good as long as you get good power and ground.

Here's my setup.

I ran it similar to yours with a ground point to the chassis under the inverter. I used a 150A circuit breaker at the battery, a 100A fuse at the inverter/amp splitter and a 80A fuse at the amp/amp splitter. Everything works perfectly with 4GA cables. The circuit breaker makes life easier since I can disconnect the power with the push of a button, beats the heck out of finagling a fuse on a battery cable.

Oh! Did you read the instructions concerning the case ground? That's not supposed to be touched to the 12v negative side of the car- it's provided for an earth ground spike should you be using power tools or extension cords outside.

 

[Dan Robinson]

I'm not sure I would trust a breaker completely as the main protection of the circuit, but that's me. A breaker has the small chance of a mechanical failure. If it somehow failed, the whole car will go up in flames. A fuse at the battery might be more inconvenient to change out (I've blown mine a couple of times while working on the circuit), but a fuse is always going to go if there is a short somewhere.

 

[Jason Russell]

I've seen bad experiences with high amperage fuses too. Namely, the fuse holder catching on fire from heat generated where the fuse didn't seat well/corroded in the holder.

I could go with double protection and add a fuse, but more connections = more resistance.