It’s not required, but it means you’ll have a fully charged EV with you when your RV reaches the destination.
A car alternator ranges from maybe 40 A to 120 A or so. A 60A alternator at full output would be 720 watt. That should be good for a charging rate of 2~3 miles per hour (2~3 miles range gained every hour), which is enough to be useful.
So what’s the downspout for?
I’m on my phone and can’t see the pic too well. But could it be a motor to apply power to the rear wheel(s)? A homemade FWD to AWD conversion (maybe there’s another one on the other side)?
Being pretty ignorant of all things electrical and mechanical, I can’t spot the difference between an alternator and a motor. And as far as the tube thing… I got nothin’.
This, exactly. I believe the Bolt (which I believe this is) does not have an ICE to provide motive power (like the Volt does). The whole idea of an RV is that you are completely self-contained. If you don’t have water, electricity, sewer, hook-ups you can survive a day or two. If you have an EV for your dinghy vehicle, that could find yourself without a way to charge it. While not a perfect solution, this provides a solution.
I’m not saying that this has to be the only possible use, only that of all the ideas floated so far, it seems the most likely. You would likely have to contact the owner to find out this is correct. The biggest argument against seems to be, not that it wouldn’t work, or that it is too complex, but that there are ways to do a better job. That may well be true, but that doesn’t mean it wouldn’t work.
He’s got a 50 gallon fish tank in the back that he’s been tending for years and he needed a way to drive it across country while keeping all the pumps and filters, etc. working.
A couple of points –
One, that doesn’t look like any modern alternator I’ve ever seen, it could be an obscure alternator but if you’re doing this why not get something that you can find at any junkyard or parts store? Alternators look like softballs with slots in them for cooling. If anything, that looks like an old school 6V generator, although I’m sure there are modern 12V generators in the same form factor.
It also doesn’t look like any AC compressor I’ve seen, AC compressors tend to have larger pulley and cast housings. This being a custom rig, though, all logic is out the window.
Two, as many, many people have pointed out, if you’re towing this thing behind an RV you’ve got a giant energy source that you can use to charge the thing via cables. There’s no reason for a complicated, risky mechanical setup on the rear wheel. Your RV is going to have a big effin’ alternator, and if that’s not big enough for you I’m sure upgrades are a few hundred bucks away. Just run some thick cables back to the Bolt and charge it that way.
I know nobody’s really stipulating that the owner understands the laws of thermodynamics or the KISS principal, but I shudder at posts that even give the concept the time of day.
Personally I think it’s something else, something brilliant that nobody on the internet has thought of.
I lean towards Team You because 1: this seems like excessive wear-and-tear on your unproven contraption to just leave it all connected while you zip around town under your own normal power sources. Wouldn’t you disconnect your tow-charger when not in tow?
Actually it could be a crude 4WD system. The Bolt is only available as FWD. Maybe the owner lives on an unpaved, steeply inclined road, and needs a little push on the rear wheel to make it up the hill when the road is slippery.
I don’t see why they need to be related. The kind of person who installs a non-standard modification on a car is the kind of person who installs several.
You might as well just declare this “art” then and say it could be decorative.
That also crossed my mind. The owner might just be doing it for the lulz, like people who put ridiculous rear spoilers on cars.
Good points, I was going to post something similar after searching for images. It doesn’t look like any motor/generator/pump since there’s no air vents. This could just be a gearbox for something else under the bumper. There’s also wear marks suggesting it may have had a larger pulley/sheave at some point. This contraption is still way too complicated for measuring wheel speed though, which was brought up in the Reddit thread. That hose looks a lot like a railroad air brake hose, although the fitting on the end doesn’t seem quite right, but it’s close.
A railroad air brake hose is a compressed air hose, right? So maybe the belt-driven device is a compressor that supplies compressed air to… something on the car, and when the car is at home, that something is hooked up to a compressor in the garage through the hose?
I’m still betting on “owner is ignorant of physics, and thinks this contraption is going to give him more useful energy than it’s costing”.
Is it possible that’s a charging cable coming off an alternator, and the guy uses it to charge something on a trailer? It would certainly be more efficient to draw power directly from the battery, but this setup doesn’t exactly scream efficiency.
I don’t see a tow hitch though.
Or those wind-up keys I used to see on the backs of Volkswagen Beetles.
Oh, and if we’re going to be entertaining the “it’s art” explanation, let’s not also forget the “object of possibly religious significance”.
Yeah, I peered pretty closely at it and reached the same conclusion, although it’s a reasonable thing to consider. Also, towing something with a Bolt seems like a bad idea, just on the general grounds that you don’t want to tow stuff with a dinky little car. Note that electric has a certain advantage for towing junk, though, simply because of the low end torque an electric motor has. This is why locomotives are diesel-electric - trying to drive the locomotive directly from a diesel engine would require a gearbox to start the train. But the electric motors powered by the diesel driven generator can manage without a gearbox.
See post #38.