Wednesday, December 11, 2013

First week with the Volt

We're around 10 days in, and we've had enough time now to form some general observations about the cost.

On the highway, as a pure hybrid, the volt gets around 32 mi/gal. Not bad, and that is a worst-case scenario for a hybrid. This really only impacts us when we go on a long trip, but it is almost 10 mi/gal better than the van, and 5 mi/gal better than the old Passat.

As a pure EV, we seem to be getting just under 2.2 mi/kW-hr. That's spectacularly bad for an EV. The Fit EV (which we have dubbed the Blueberry in a nod to Psych) gets 4 even with my lead foot driving style. Tesla claims 3 for the Model S - even with its ginormous battery. 2.2 mi/kW-hr is just over 70 MPGe.

Chevrolet, in their informational data shown either on the web or in-car, shows a downright obsession with MPG - which they calculate by dividing the odometer reading by the amount of gasoline consumed. They do keep a cumulative kW-hr intake that you can view on a charging detail page, but the prominent placement of MPG seems intended to fool you into believing that electric miles are somehow free.

We live in Santa Clara. We have perhaps the lowest electric rates in California. Even so, the top tier is 10.2 ¢/kW-hr, which is the equivalent of $3.41 per gallon in energy equivalent terms. That's cheap, yes, but hardly "free." Now, granted, some charging stations - like the ones we have at work - are free, but this is going to be the wife's car, and she's likely to do the overwhelming majority of her charging at home.

So what are the final numbers? In terms of money per mile, the Fit EV is 2.55 ¢/mi. The Volt as a pure EV is 4.63 ¢/mi. On the highway, as a hybrid, with $4/gal gas, it's 12.5 ¢/mi. Of course, that's purely the cost of energy, and it assumes all kW-hr are 10.2 ¢ and all gas is $4/gal.

Clearly, "don't believe the hype" would be overstating it. As an EV, the Volt is almost 3 times less expensive per mile than it would be as a hybrid. But I do think that Chevy's pushing straight MPG is a bit disingenuous.

Tuesday, December 10, 2013

What is the plural for "Hydra?"

There are now two Hydras in the world.

We got my wife a Volt, so we are now a two EV family. And instead of installing a second charging station, I built us a Hydra. We spent a week moving the plug back and forth, but I was always nervous that I'd forget to charge one of the cars. And if it was the Blueberry, that would be a particular problem (that's our name for the Fit EV).

There were no particular surprises, but a couple lessons learned:

1. The new Leviton cables don't have a proximity wire in them. That's not good for Hydras, though they do still work. The new cables are also thicker, so they probably require a CG-17 instead of the 16 from Polycase. I don't know if it was that it is cold tonight or the cables are new, but they're quite stiff.

2. I simply must remember to watch out for protrusions near the edge of the internal panel. Two standoffs wound up colliding and I had to use a Dremell to cut them off.

3. I cut myself stripping the outer jacket. It wouldn't be a Hydra if I didn't bleed making it I guess.

4. I had originally used a right-angle plug for the i2c LCD connector, but that hit a standoff for the LCD, so I had to bend it up.

5. The new box I chose from Polycase has much more room inside, but at the cost of, well, being bigger.

I had intended to take a bunch of pictures to make a tutorial on building a Hydra... but then I got into actually building it and forgot.

Sunday, December 8, 2013

Questionable consequences

I recently bought a toaster oven and immediately took it apart. It is now a surface mount reflow soldering oven, but that's been covered in detail elsewhere.

As I was cleaning stuff up in the garage, I ran across the instruction manual for it.

So what?

This little snippet caught my eye and made me chortle:

LOL. Or what, exactly?

I kind of get where they're coming from. The surfeit of ambulance chasers we've grown in this country during the 20th century has made CYA an all too familiar manta anymore. And that's kind of a shame. But when I took the first screw out of the back of that oven, I knew right then that I was abrogating the manufacturers warranty and taking complete responsibility on my own.

I thought that the demise of Heathkit and the move in the electronics industry to surface mount spelled the end of the electronics hobbyist. But the hackers adapted and overcame, and now anyone with a very modest investment can create things virtually indistinguishable from commercial products, thanks to the likes of Eagle,  OSHPark and the Arduino project.

Sunday, December 1, 2013

Alternative controller idea... all-in-one backpack

It occurred to me today... I've been trying to reduce the cost of the controller board by shrinking the board. And that works, but the most expensive component is the LCD display backpack.

That got me thinking... Is there room on the backpack form factor for both the backpack's display i2c adapter circuitry and the Toast-R-Reflow controller?

And, sure enough, there is.

The board price goes up a bit - it's now $7.50 each instead of closer to $3 - and you need to add a LCD display ($11 on DigiKey for a monochrome backlit model - the Toast-R-Reflow doesn't really need the fancy RGB backlighting) and a handful of other SMD parts.

The net result is that it looks like I will be able to put complete controller assemblies for $40 each as opposed to $25, and then you need to buy a $30 LCD display backpack (or the $25 AdaFruit shield).

If you feel brave, the board is shared at OSH Park, but the basic controller design hasn't been fully tested yet, so no guarantees, at least at the moment. But if the basic controller design works, then this variant will be my next attempt.

Scarlet's new Chevy Volt

Anyone who lives in Santa Clara really ought to have an electric car. Santa Clara's municipal electric utility, Silicon Valley Power has maybe the cheapest rates in the entire state. The upper tier of 10.2 ¢/kW-hr equates to around $3.40 per gallon of gas equivalent. And, of course, an electric car is about 3 times more efficient than a gasoline car.

But unless you buy a Tesla, it's impractical (at least today) for a family to do entirely without gasoline power. So when it came time to trade in Scarlet's car, we looked purely at plug-in hybrids. Unfortunately, that cuts way down on the choices. It amounts to choosing between Chevy, Toyota and Ford. We wound up going with the 2014 Chevrolet Volt. We went with the cheapest model, which was around $7500 (or so) less than the tricked out version.

What we miss with the lower model is some of the new high tech driving stuff, like parking assist, lane departure warning and (I think) radar assisted cruise control and built-in navigation. The Volt does have OnStar assisted turn-by-turn navigation, but the way that works is that they download the directions as a set of GPS waypoints. The car doesn't actually have a map at all. If you go off-route far enough, it tells you that you need to phone home again to get updated routing. It's good in a pinch, but if you want an actual map, you need to use your phone.

I took a trip to San Francisco. Highway driving is where EVs and Hybrids actually don't do so well. 11 kW-hr of electricity took me just under 30 miles at 75 mi/hr, and the gasoline engine was able to get around 32 mi/gal after that. Not bad, and it sets expectations for the occasional road trip. But apart from those road trips, it's quite likely that Scarlet won't use a drop of fuel, and will get more like 3 mi/kW-hr or so (the equivalent of around 100 mi/gal), again, at a "fuel" cost of under $3.50/"gal".

Oddly, the cabin is configured as 4 bucket seats. Where normally you'd be able to squeeze 3 small folks into the back seat, that's not an option here. However,  the back seat does come with a center console of a sort, and the hatchback area is opened to the back seat. There's also power outlets for both rows of seats, as well as a power port in a little cubby on top of the dashboard (I guess for standalone GPS units?), and the front also has a USB jack nearby used for connecting to the entertainment system (and, yes, it does charge an iPhone with the Lightning cable). Connected that way, it can also control Pandora running on the phone, which is quite nice. Siri works more or less as you'd expect (via Bluetooth), but you must engage her by using the home button on the phone.

I'm not sure how I feel about OnStar. They can place hands-free phone calls for you, but they charge extra for that, and you're not using your phone to make the call (so I'm not sure what the caller ID shows for the people you call), so we didn't opt for that. You can ask them to send down navigation routes, but there's no map. They also have an emergency response system built-in, so they know when the airbags deploy and stuff like that.

The efficiency displays are slightly disingenuous, since they talk about an overall miles/gallon, which they calculate by dividing the odometer by the amount of actual gasoline used. The implication there is that the electricity you "pour" into the car has no cost, which isn't really accurate. Chevrolet salesmen perpetuate this little bit of faulty arithmetic as well. It's true that (at least today) many public charging stations are free, but that's certainly not the case for charging at home.

The only other gotcha we ran into was that by default the Volt is set for a "charging cable theft alarm." What that means is that if you disconnect the J1772 plug without the key being nearby the car alarm will go off. That happened at 10 PM the first night when I moved the plug to the other car, and I turned that nonsense right the heck off.

Anyway, so far it's going pretty well.