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My install of Xantrex PROwatt SW 600

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cinergi

Active Member
Sep 17, 2010
2,176
42
MA
The laptops I use require more power than available via a small inverter on a cigarette lighter outlet. I even tried wiring this into the cigarette lighter outlet and, while I didn't blow any fuses, the outlet got too hot for my tastes. I hadn't gotten around to fully-installing the inverter (wire it to the 12v battery) until today because of the complexity of routing the wires through the firewall and generally taking the car apart to get "under the hood" ...

I was inspired by this thread as it showed me a way to get the wires over. Long story short, I decided to drill two holes and run #4 wire (the unit will draw up to 55 amps) from the battery into the passenger compartment and mount it there. I took some photos (below). Here's what I bought to achieve all this:

To drill 1/2" holes for the grommets for the #4 wires: Amazon.com: Neiko® 10193A Titanium Step Drill Bit Set, 28 Sizes, SAE | 3-Piece Set: Home Improvement
Lugs (used 1/4" stud for Xantrex and positive battery terminal and 3/8" stud for negative battery terminal): Amazon.com: Install Bay Copper Ring Terminal 4 Gauge #14 25 Pack - CUR414: Car Electronics, Amazon.com: Install Bay Copper Ring Terminal 4 Gauge #38 25 Pack - CUR438: Car Electronics
Grommets: Amazon.com: Cal Hawk AZGA125 Rubber Grommet Assortment Set Electrical Gasket 125 pc: Home Improvement (used the EWG-26-3/8 x 1/2)
Fuse holder: Amazon.com: DB Link AGUFH1 AGU Fuse Holder: Car Electronics
Hammer-crimp tool: Amazon.com: NOCO D800 Blue Hammer Indent Crimping Tool: Automotive
80-amp fuses (as recommended by Xantrex): Amazon.com : DB Link AGU80 80 Amp Gold AGU Fuses : Vehicle Amplifier Fuses : Car Electronics
#4 wire: 4 AWG Premium Extra Flexible Welding Cable 600 VOLT COMBO PACK - BLACK+RED - 15 FEET OF EACH COLOR - Made in the USA!: Amazon.com: Industrial Scientific

I also bought heat-shrink tubing and a mini butane torch from a local hardware store. I used some screws I had lying around to mount the unit to the carpet (which is backed by relatively thick plastic).

Some notes:
  • I had to oil up the wire to get it through the grommets. It's a very tight fit
  • I took apart the frunk as shown in the referenced TMC thread above
  • I took off the front passenger wheel and well to gain better access to the firewall for drilling
  • The drilling was quite easy - the metal isn't very thick
  • In the interior, I took apart the panel under the glove box, the carpet panel and side panel of the center console, and the door sill
  • I'd taken apart the frunk twice prior to understand what I was up against so I could order the parts I needed

Images coming next post

- - - Updated - - -

Wheel removed, wheel well material removed; grommets installed in new holes and wires run through them
IMG_2940.JPG

Close-up of installed grommets and wires (wheel well view). I drilled the holes right next to the sunroof drain
IMG_2941.JPG

Passenger footwell with wires coming through. Note that the panel below the glove box and the door sill have been removed. The carpet's been move aside a little
IMG_2942.JPG

Close-up of installed grommets and wires (passenger footwell view)
IMG_2944.JPG

Wider shot of passenger area
IMG_2945.JPG

Frunk taken apart; wiring rough-in
IMG_2946.JPG

Finished product
IMG_2949.JPG
 
No, I connected to 12V. No desire to mess with 400 volts or get an inverter that deals with that kind of input voltage (which is likely more expensive).
As for direct DC -- it's more than just my laptop (which is a work laptop -- so no choice there) but personal laptop and other lower-power 120v equipment as well. It's always nice to have a 120v socket in a car (that's why you see it as OEM in some newer cars). The ~100 watts I could pull from the 12v lighter socket just wasn't enough for the power-hungry laptop (and I wanted a better AC output than those cheapie lighter-socket-inverter)
 
I connected to the 12v battery terminals. Somewhere in these forums was a post of the DC-DC specs which showed it was capable of way more amps than this thing would ever pull. I put an 80A fuse in my run. The specs of the battery are posted elsewhere in here, too. The only unknown is the AWG of the wires from DC-DC to the battery but visual inspection was "they're big enough for what I'll be doing" -- e.g. I don't plan on pulling 55 amps (even though I sized the install that way).
 
It is best to put the inverter close to the battery. The 12v side has high amps while the 110v side has 1/10 as many. At 12v, the wire resistance adds up quickly causing voltage drops. Keeping that wire short minimized the voltage drop. The high voltage wire should be protected with a GFI at the inverter and can be run to were you need an outlet. You can get outlets and other supplies at a Marine or RV suppliers. Some inverters have remote controls that can be located near the outlet.
 
I would have mounted the inverter near the battery (and actually plan to do so when I have a moment...) however it's nothing to do with current or voltage, it's just that I don't want the whole box visible in the passenger compartment, I plan to install a wall outlet flush mounted instead.
 
Yeah I debated mounting it inside the frunk and running a 120V line instead. But then I'd need to make sure I didn't pack the frunk in a way that would interfere with its airflow etc. Ultimately having the unit there in the passenger footwell area turned out to be OK with me (and I didn't need to deal with remote control and whatnot)