Nissan Leaf: 4 months down

I’ve now been driving my 2013 Nissan Leaf for about 4 months. A couple of notes:

Battery Capacity

I lost a bar of battery capacity around 18,000 miles. This puts the car probably near 2.5 years old, and is indicative that the car spent a lot of time in the heat down in Georgia with its previous owner (and likely the previous owner didn’t go out of his way to use the battery in long life mode). The LeafSpy app currently reports battery State-of-Health at 82% with 19,000 miles.

I think one of the more annoying things about EVs is that the range is specified on Day 1, whereas the average range you’ll see as an owner of a leaf for 5 years will be closer to 80-90% of that figure, dipping to 70% at the end of the pack life. This is much more of an issue with an 85 mile range car than with the new 110 mile leaf or a 200+ mile range vehicle.

LeafSpy

I got a Wifi OBD dongle and the LeafSpy app, which has enabled me to access detailed statistics about the car including tire pressure, exact State-of-Health of the pack in %, cell balance, pack temperature sensors, etc. It also allowed me to configure the car to unlock when I engaged park instead of waiting until the vehicle was fully shut off (the only problem is that if I absentmindedly shut the car off without putting it in park first, the doors don’t unlock).

On a related note, I have gotten the car into the “Engine Power Limited”/”Turtle” mode now. It engages at 5 GIDs worth of power as reported by the LeafSpy app, though the indicators for capacity inside the car have long since deactivated at that level of charge

Service

I brought the car into the dealership for a voluntary recall relating to some doodad freezing and they appear to have updated the software. Among the changes, I can now shift into drive sooner after turning the car on and the car makes a different jungle noise when starting up (yay).

Biggest Grievances

Overall, I love the car, but as an engineer there are a few points about it that really irk me.

Drivetrain

The car’s handling of power versus accelerator and brake movements is designed with the first and foremost goal of making people who used to drive automatic transmission ICE vehicles feel at home. I understand why this was done, at least in the primary Drive mode. It applies a bit of regenerative braking to make the car feel like an ICE car when you take your foot off the gas, it creeps forward when you remove your foot from the break.

Nissan also introduced a “B” or increased regenerative braking mode. I really love this mode because it allows you to operate the car most of the time without having to use the brake pedal. However, this mode is still engineered to make drivers of automatic transmission ICE cars feel at home rather than trying to make the mode work as it should.

If I’m going 60 MPH and I release the accelerator in B mode, it will apply maximum (30 kW) regenerative braking. However, as soon as the car hits 45 MPH it starts to inexplicably reduce the amount of regenerative braking that it applies, all the way down to around 8 MPH where the car stops applying regen and will instead apply power to the wheels to keep it coasting forward. It’s obvious that if I whale on the brake pedal that it can apply 30 kW of regen all the way down to below 10 MPH, but instead of applying maximum regenerative braking in the regen mode, the engineers instead opted to still require you to press the brake pedal to get maximum regen. Even more frustrating is that the car won’t apply max regen unless you brake quite hard with the standard pads. This also makes no sense: the EV should prioritize regen — no brake pads should be applied until 100% of regen is in use. This increases the efficiency of the drivetrain and reduces wear and tear on the car.

Recommendation: Provide a settings menu to configure the handling of the car in D and B mode. I want to be able to disable the creep in both modes, use D mode to apply no regenerative braking at all when the accelerator is lifted off the floor. I want to use B mode to apply 100% regen available at all speeds so that I can slow the car to a stop without touching the brake. Bonus points for either retooling the brake pedal to engage maximum regen before using the mechanical brakes or providing a separate control that can be used to apply only regen.

Battery Capacity

Gas vehicles indicate tank capacity by a gauge, which makes sense because it is measuring a level of liquid sloshing around a tank. The EV, in comparison, has the cool capability to tell you nearly exactly how much energy is in the battery down to the Watt Hour.

So the Leaf can tell your exact efficiency in Miles/kWH and it knows the amount of kWH in the battery at all times yet the 2011/12 Leafs literally gave only 12 rough “bars” to indicate available charge and the “guess-o-meter,” that thing you have in your gas car that roughly estimates miles till empty and is usually relegated to the back page of some dash menu.

Leaf owners quickly discovered that the car would tell you exact battery charge through the OBD port and hacked meters to display the real number onto their console with duct tape. In the 2013 Leaf, Nissan, equipped with all the wonders of modern technology, provided an entirely arbitrary percent scale into the dash menu, leaving the near-useless guess-o-meter displayed prominently, and 1/3 of the heads up display dominated by the worlds most useless “tree meter” which literally illuminates a small forest as you drive to make you feel good about yourself.

Here’s why this is terrible: the guess-o-meter basically assumes you will be driving the same exact way for the entire trip. If you drive half the trip on a state route at 40 mph and half the route on an interstate traveling 70, the guess-o-meter will reliably be off in its estimate in both directions because it will assume that the rest of the trip is to be made during the same conditions under which you start out.

Even more infuriating, in the spirit of “fog of war” the leaf stops telling you how much power it has left when it gets down to 5% remaining charge in the battery pack. The only way to know at this point is to plug in a duct tape OBD meter.

Recommendation: provide a meter for kWH in the battery pack, ideally either replacing the guess-o-meter or the tree meter or at a minimum in a software update for all previous leafs. Bonus points if it’s configurable (the user can select %, kWH, or guess-o-meter next to the bars).

Charging

You cannot open the charge port while the car is on. Rather than allowing me to pull up to a charger, plug in the charger, and have that action disable the drivetrain, the leaf requires me to shut off the vehicle before charging. Only after charging I may turn the vehicle back on in a “Drivetrain disabled” mode which allows me to use the climate control and radio. It’s really annoying, especially since an entirely electric software-driven car there is absolutely no reason why this isn’t feasible.

Entertainment System

The entertainment system feels like I’ve reentered the dark ages. Honestly it’s better to make cars that can slip in Android tablets into the dash than make these archaic resistive touch screens that display blocky unscrollable and confusing menus. For instance: the leaf has a spare SD card slot. You’d think that you could load music onto that spare SD card and play them through the entertainment system, but you’d be wrong. Further, the entertainment system can only read MP3 files off any USB attached storage. How difficult could it be to implement FLAC support?

Quick Charging

Quick charging is great, however there are no Quick Chargers convenient to getting from Boston to Portland. With a single quick charge off I-95 north in New Hampshire, this would be easily doable. Without one, I’ll be required to drink beers at a brewery while I wait for my car to charge outside for two hours.

 

World, meet Fergus! My 2013 Nissan Leaf SV

Earlier this summer while I was toiling away in Seattle, I asked my dad a crazy question:

What would you say to car sharing a Nissan Leaf and your Passat?

Needless to say that was the beginning of a very slippery slope. By mid-August when I returned we had visited a used car dealership in southern MA to take a look at our options. We decided that this was to be a year long experiment. Continue reading World, meet Fergus! My 2013 Nissan Leaf SV

24 Bit Audio

Take a look at this article on the myths and truths of 16 vs 24 bit audio:

http://www.head-fi.org/t/415361/24bit-vs-16bit-the-myth-exploded

So yes, I am justified in running my console in 24 bit. 24 bit or higher is important when mixing because if the audio comes in only up to a quarter of the usable dynamic range, you still have 22 bits of range to work with. In addition, when summing, it’s important to have greater latitude (but that’s mostly within the effects processors themselves). If you tried to do the same stuff with CDs, you could end up with less than 16 bits of range especially if you begin applying effects. Using additional bits in mixing allows you to ensure that you maintain an even level of quality in the final product despite variations in source levels and processing. But all ye enjoy ye CDs.

Particularly interesting is the point about dither. When you put the dither in the frequencies that humans don’t hear as well (15-20k), the randomization of the quantization errors still achieves the same effect but it’s less noticeable.

Definitely worth sharing to the audio nerds though. Of course, sampling rate is not covered here and that’s a different discussion 😉

The Shannon-Nyquist theorem guarantees complete reproduction of the input signal given a sampling rate at greater than twice the maximum frequency. This is true for a discrete signal, however that doesn’t account for quantization and in the digital world would require infinite precision of the ADC. Obviously that’s not possible. Hence the dither.

Research on the DSC 1832 Series Alarm System

3/11 – Updated the smoke detector wiring per HSC tech support.

The DIY alarm system is not a new idea, and there are plenty of wireless “ready to go” systems where you just plunk the old thing down and it’s ready to go.

But that’s no fun. Meet the DSC 1832 PowerSeries alarm panel:

A simple kit for the 1832 from the homesecuritystore.com website
A simple kit for the 1832 from the homesecuritystore.com website

Continue reading Research on the DSC 1832 Series Alarm System

Iced Americano from Costa: Not an iced coffee

As at least one reader of my blog knows, I’ve been spending some time in the UK over the past day. To help with the jet lag and grueling tour schedules, I accompanied my somewhat British friend to Costa, the British “Starbucks Equivalent.” (We always need more Starbucks…that’s why there are boatloads of Starbuckses in Britain.) Continue reading Iced Americano from Costa: Not an iced coffee

No More Wall Warts: The DC-DC Buck Step-Down Converter

A few months ago I saw this little gem on eBay and snagged it for something like $3.50. After a month (gotta love Chinese envelopes) it showed up at my door.

dcdc2

My mom asked, appropriately, “What the hell is that?”

To her, probably nothing. To me, however, a very cool gadget.

If you’ve experimented with electronics, you’re probably aware of the really annoying fact that all these devices require different voltages and currents and practically no two are alike. If you’re exceedingly lucky, your device will take a standard 12V 1A center positive wall-wart, available in droves. Or maybe a 5V 1A supply (those are also common).

But a lot of the time, you end up with equipment that requires odd voltages. That’s where this device comes in handy. Plugged into the input, I have a 19V laptop transformer that I got for $6 on Amazon Prime for a friend (I thought I lost her adapter, I later found it, ended up with it). Clipping off the annoying connector revealed two beautiful red and white wires which I stripped and tinned. Many of these adapters have coaxial arrangements of the cables (this one has one of those little plastic cylindrical enclosures. Maybe that’s where it changes from coaxial to double strand?).

Basically this converter consists of a simple switching circuit with a built in inductor. Two filter capacitors on the input and output stabilize the voltage. By switching very quickly between charging and discharging the inductor it’s able to maintain a steady voltage across the outputs which is stepped down from it’s input. The max voltage it can produce is 2V less than the input or something like 26V, whichever comes first. It can supply something like 2.5A.

Basically, for $10 I have a 2.5A fully adjustable power supply. A tiny screw allows fluid adjustment along a very wide range. When combined with a 19V supply at 3A, it’s capable of supplying most every gadget I have in my collection with the necessary voltage. Is it stable as the dickens?

No.

It tends to jump a little high after I dramatically reduce the current draw (releasing the PTT of a radio). But all in all, not bad for $10. And you can always attach a gigantic capacitor across the outputs for stability (check out the MIT Flea Market if you’re interested in gigantic cheap capacitors for arc welding or other uses. be careful though they’ll burn you into a fried chicken if you’re not careful).

Here it’s powering my Turnigy Accucell 6 universal battery charger to give my radio batteries a boost. I have a 25 Amp supply but for charging at 1A current, that’s a little wasteful (not to mention huge).

Bottom line is that I would highly recommend perusing eBay for one of these things. The screw sets the output voltage which doesn’t change as input voltage varies, and these are supposedly 95%+ efficient.

The Andre seal of approval is bestowed upon this Chinese gizmo.

Batteries for Breakfast: Getting my battery charger NOT to fry my batteries

I’ve been playing a lot with the EFJ 5100 series portable radios. The radios are excellent units by my standards (I will admit to not yet having used an XTS 5000). I have a couple of original EF Johnson battery chargers for the 5100 series. They’re moderately strange looking items, allowing you to place the radio in as normal for charging on the rear battery contacts, but also a slightly unconventional method of strapping the battery to the charger.

efjcharger

Continue reading Batteries for Breakfast: Getting my battery charger NOT to fry my batteries

Das Telephone Line Tester (Wilcom Model T303B)

Yesterday at the MIT flea I happened upon this gem, a little bad boy from Wilcom called the “MODEL T303B SIGNALING SENDER.” What is it do you ask? I have no idea. What does it do? It beeps. How much did I pay for it? $7.

Wilcom Line Tester
Wilcom Line Tester

It’s dated 03/1983 Manufacture and appears to have been owned by GE. Continue reading Das Telephone Line Tester (Wilcom Model T303B)