second 12 volt battery - 2020 edition

That would be best practice, as otherwise you only have the 125 A fuse link between you and the converter, and the 140 A fuse link between you and the battery. In the worst case of a short to ground in your inverter or your wiring, both of those could dump on you in parallel.

Any wiring and equipment you add ought to have a fuse of its own, as near as possible to where you tap it, sized for what your added equipment and wiring can safely handle. The job of the car's fuse links really is to put a sane limit on the worst-case current the downstream branch fuses have to be able to break.

A multimeter is a good thing to have around in any case, and it will give you a rough idea whether you've found a usable ground point or not ... as in, if the spot is painted and the conductivity genuinely sucks, a multimeter will tell you that. They don't really have resistance ranges low enough to show differences between ok, good, and better ground points; that can be done with specialized gizmos that use large test currents and measure very small resistances. Probably most people don't need one of those knocking around the house.



If you want to do a test there, I would put one meter lead on that bolt you're testing, and the other just on the nearest actual ground point that you find. (Look for little clusters of usually white-with-black-stripe wires joining together at a screw.) One of them, of course, is where the negative battery cable attaches to the body, though probably there's one or two closer to your chosen bolt.

Again, you're trying for as isolated a measurement as possible of the resistance from your chosen bolt to the car body, which is your path forward to the DC/DC converter where the power is coming from. If you stick your other meter lead on the negative battery terminal, you're unnecessarily making a combined measurement of the bolt you care about, the near-the-battery ground point, the cable from there to the battery, the battery clamp....

 

My understanding is that welding cable is the most flexible.

 

When I find myself wanting a nice fat wire made up for something, I typically just walk into the local automotive electrical place in town. I say I'd like it this long, red please, ring terminal this diameter on this end, that diameter on that end, and two minutes later he hands me it, done, in finest floppy welding cable with the heatshrink tubes still cooling off at the ends, and he rings me up and I take it home and put stuff together.

Could I do it myself? Sure, if I had around the cable and all the sizes of terminal and crimp dies and heatshrink and so on. But, you know, it takes Mark two minutes and the price is fair and it's beautiful.

 

Wait a sec ... look at those goofy handles on the CFX 28.

It fits in there with the handles on, but my oh my ... those add, like, 39 mm ... on each end. And they're bolted on.

A CFX3 35 says it's 694 mm long, compared to 620 mm for a CFX 28. Does it have goofy handles on the ends too?

It appears to. I wonder, if somebody wanted a CFX3 35, and removed the goofy handles, and just bolted on some webbing strap loops instead, would it slip into that space?

It's also 398 mm across, to the CFX 28's 342. But that doesn't look like the limiting factor, if you're free to slide the passenger seat forward a little bit.

 

At first, I wondered about removing the handles. But then realized how difficult it would be to move without the handles. As it is, it's pretty heavy for one person when it's filled with food. Doable, but heavy. As far as the width, the passenger seat already needs to be slid forward to make it fit nicely. Not all the way forward, but enough to not give a passenger there comfortable legroom. That's fine if you travel alone. If traveling with a second person, I put the refrigerator into the storage box in the back. But then you can't sleep in the car.

 

Nylon webbing from the fabric store. Grommets. Bolts and washers fitting the original threads. Could go to town and leather-wrap the webbing loops if you wanted.

Probably easier to lift with decent strap handles than with the goofy spring-loaded ones....

 

Any concern that the fan is on the side and its wedged in pretty tight?

 

I would say no, as the fan openings are fairly low on the unit; one ends up aligned with the space beneath the passenger seat (which even has its own air supply, if you have the HVAC on 'floor' or 'face/floor'), and the other aligns with the clear space below the rear seat and has a straight shot to the battery fan intake.

Hmm, so the CFX3 35 handles aren't quite as bulky, I take it? If it had handles sticking out 39 mm like the CFX 28 does, by my arithmetic it'd be 4 mm shorter with those puppies removed.

 

That matches the 694 mm figure I had looked up.

 

Right. The fan is on the left side, and there are tiny vents on the rear, and bigger ones on the right side. So care does need to be made to make sure there is some clearance on the left (fan) side. Otherwise the fan will just blow into the padding under the rear seat.

 

Clear space below the rear seat? Not on my Prius. There is no clear space below the rear seat, much less a straight shot to the battery fan intake. Under the rear seat is a carpeted wall. So care does need to be taken such that the front passenger seat is far enough forward to give air space between the refrigerator and the rear seat.

As you said, the right side of the refrigerator has vents which sit low enough to allow airflow from under the front passenger seat, and yes, the car vent blows under the seat to the back, so that's not an issue. The small vents in the back of the refrigerator are also not an issue, unless one forgets and jambs a sleeping bag down there!

 

I guess what I meant by "clear space below the rear seat" was that the upper surface of the seat cushion projects farthest forward. If that's against the side of the fridge, there is clear space lower down where the vent opening is.

 

Right you are! With the seat folded down (and the head rest removed), there is ample space between the frig and the bottom of the rear seat.

There are another couple of places the frig fits:
- Sideways in the back in the box (with the cover removed). That's where I most often put it. The retractable cover then hides it nicely.
- Another location is on top of the back cover, up against the rear seat. To fit, the retractable cover needs to be popped out. This allows you to use the space next to it to sleep, or for "other business" as needed (with a Habitent for privacy). The wood is my table, which is here to add strength when I sit there.



There are places I've tried where the frig does NOT fit:
- It does not fit on the floor of the front passenger seat
- It does not fit in the box in the back when aligned front to back - the hatch won't close
- Don't put it on a seat, it's not level

 

They offer it for sailboats though, say it works heeled up to 30°.

Car seat's probably never over that far, even on a beam reach.

 

You are correct. I learn new things here all the time. I'm thinking that the seat is not a very stable location. It will fit on the front seat tipped up a bit, in front of the front passenger seat, as well as in the rear box tipped up (on a 2x2) such that the hatch can close. I still wouldn't put it in one of these locations.

Glovebox?

 

Hey @geedub or @Terrell, have you ever seen a CFX28 blink its interior light, a nice steady obviously-deliberate blink, about 1 Hz, from the moment you open the lid?

The small four-language paper manual that came with (English/French/Spanish/Portuguese) does not say anything about that. The sixteen-language manual downloadable from their web site says it's a signal you had the lid open too long:



Only I'm talking about sometimes just opening the lid and seeing the interior light flashing right away, like maybe it thought the lid was open when it wasn't?

Somebody else has reported the same thing and didn't seem to ever get any clueful response from Dometic (other than "your light's flickering? We'll send a new light." No, guys, it's not "flickering", it's an obvious programmed flash that means something.)

I haven't even managed to spot how the thing is supposed to tell when the lid is open or closed yet.

Edit: briefly refrigerating my phone while recording video shows it sure 'nuff isn't recognizing that the lid is closed; the light keeps blinking in there the whole time. But sometimes it's fine. Something flaky about the lid sensing, I'd guess.

'nother edit: there is one exact spot on the front right corner of the lid where you can stand a nutdriver on end because of the magnet that's inside the lid there.



... and of course one corresponding spot inside the front lip of the enclosure where if you hold a magnet there, the light goes out. (And resets, and doesn't blink.) But the lid hinges have some freedom to shift left or right, and when the lid is shifted over leftward, the magnet doesn't seem to align with the switch so well.