Real EV Charging Rates from the Bay Area

So the 2005 Toyota Sienna needed to be replaced, and I got a 2017 Nissan Leaf. This particular model is an S trim (read cheap) in Red. So now that I’ve made the leap into electric vehicles, it is time to determine what the options for charging are. I’ve had the car for about 2 weeks as of this writing, so I am definitely not an expert. So there may be some inaccuracies in the information below.

Fortunately at work I have free EV charging, so knowing how the public charging works is part intellectual exercise, as well as a preventative in the case where I really need it. Right now I don’t have an EV charger at home (and neither do I have solar).

For reference, my Sienna would run at about 16 mpg, and I would get around 350 miles for a full tank of gas of around 18 gallons. So a full tank would be around $80. More on this later.

Charging in the South Bay area of Silicon Valley has a few options, with a charging option usually being within a few miles. The most popular options are Chargepoint, EVgo, and Volta. Some cities (eg: Palo Alto) and some stores (eg: Best Buy) have free charging (typically through Chargepoint). There are also some interesting charging deployments coming up through companies like Powerflex, where the Mountain View/Los Altos school district is deploying charging for school staff with discounted rates after hours for the public.

Different public companies have different ways of charging. Chargepoint is typically charged at a rate per hour, pro-rated against usage. EVgo charges per minute. Blink apparently charges per kWh for their chargers. I’ve had a quick play with charging at both Chargepoint and EVgo stations, so the following represents how I see charging working. The sample space is small (three charging sessions), but the numbers seem to reflect what I’ve been seeing implied with blogs.

So let’s start with Chargepoint. I’ve used Chargepoint at Best Buy, City of Sunnyvale, and Cupertino Rotary club. The Sunnyvale Best Buy charger was broken, the Chargepoint would detect and start, but would never deliver any power. It is marked as Free, so it might be a good option if it worked. It might be that the charger locking head was broken and so was unable to “lock”, and so would fail. Interestingly, Chargepoint didn’t notify that there was a problem.

The other times I’ve used Chargepoint it worked as expected. You swipe, plug in, and the charging starts. You go do what you need to do and come back, and be on your way. In both these cases, the systems where 6.6kW rated units. According to the Chargepoint app, one provided 6.0kW, the other 6.5kW. Since Chargepoint charges per hour (or part thereof), a poor charger choice could make quite a difference. In these two cases, I was there for just under an hour and had around 6kW added to the car. This is equivalent to about 20-24 miles. Not bad for around $1.50. Both City of Cupertino and City of Sunnyvale both charge $1.50/hr for charging.

Now EVgo is a bit different, they have DC chargers, capable of delivering about 40-50 kW. I charged for just under 8 minutes at an EVgo station, costing $2.10 (they round down, which is nice). They delivered 5.8kW of power in the 8 minutes.

DC chargers generally only deliver power to 80% of full, so there are some unusual behaviors that happen on the way to 80% that are actually quite important. In the case of EVgo, I was monitoring the power with the Leafspy Pro app on my phone as it was charging. The image below is a screenshot.

As you can see the initial charging power (green & blue line) was around 46kW for the first few minutes, and then began to drop off as the system approached 80% (red line). This is not unexpected, but it does have an impact on the overall power delivery for a session. The initial rate was 46 kWh, the final rate was around 41 kWh, and the average was around 43kWh.

The table below tabulates the costs as rates for the different charge rates that I used.

Cost/kWhCharge Rate
DC 5.816
Level 2 5.403
54 $0.25
ChargePointLevel 26.97 $1.5964 $0.23 6.53

By comparison, the PG&E charge rate is $0.22 for Tier 1 or $0.27 Tier 2 for the base E-1 rate plan, or for my bill (which includes the Silicon Valley Clean Energy Electric option) it comes at around $0.21 or kWh. So with my current usage, the a good Chargepoint Level 2 charger will be cost equivalent to my plugging in at home with the E-1 rate sheet.

I’ve applied for the EV-A rate sheet from PG&E, even without the EV it would actually save me about $10 over the course of a year. With the EV-A rate sheet, PG&E provide Peak at $0.49, Part Peak at $0.27 and Off Peak at $0.13 during Summer. During winter, it is $0.34, $0.21, and $0.13 respectively.

The three options that I haven’t used yet are Blink (apparently $0.49/kWh for DC fast charging), Powerflex (apparently $0.15/kWh with a mix of DC and Level 2), and Volta (apparently Free).

So with the EV-A rate plan it is considerably cheaper to charge the car at home off-peak vs a public charger. Powerflex is not local to me, but intriguing and useful in a pinch, and Volta stations tend to be fairly busy (free of course is always in demand). Blink seems to have a charging model that would be a last resort.

With all the per hour charging systems, you really want to ensure you get the best bang for your buck, so you should make sure you know which chargers deliver the highest power. A good Level 2 can provide 6.6kW, but a poor one can deliver considerably less. Knowing the good Level 2 chargers can give you an effective 10% discount on pricing. With a DC charger, it looks like you want to do the same, knowing that the stakes are even higher.

Finally, public charge stations that charge per hour, really are intended to move you from empty up to something safer, but you shouldn’t expect that they should fill your car up. For DC, you definitely start getting power limited at around 65%, and with Level 2, I’d expect you can go higher, but you’d find the charge rate would begin to drop off for the final trickle charge.

If in the end, I don’t have charging at work, I’ll likely charge at home and be comfortable knowing that home charging provides very attractive pricing with the convenience of a full car first thing in the morning.

I’m likely to go Solar before the end of the federal tax credit, so then it will completely change the equation. I’m paying close to $2000/year for power, so with the new Tesla Solar pricing (around $8000 for a 4k unit), it will likely pay itself off within 5 years, even up front.


Career Stages of A Typical Software Engineer

This is a repost of a long form response to quora question (What are the typical stages in the career of a software engineer?) which itself was derived from an answer – Matthew Tippett’s answer to What does this mean for a software engineer: “You are not at a senior level”?. Adapted and tweaked for the new question, now tweaked for the blog.

Each company will have its own leveling guide, ask your HR department or search your intranet. It should go through a clear set of expectations for each grade and the different attributes that each grade should possess. Your manager may not even be aware of them – but they should provide a basis for you to understand the career progression.

Flat organizations will have only 3 or so (Jr/Mid/Senior/Exec), other organizations will have many (Assoc/Eng/Snr Eng/Staff Eng/Snr Staff Eng/Princ Eng/Snr Princ Eng/Dist Eng/Fellow). Apply the following to your company and don’t expect direct portability between companies.

Grade Levels

First, we’ll go over a hypothetical set of grades – generally well rounded against a lot of companies – some will have different titles, but will generally have a a common set of attributes.

The Career level is arbitrary but what you’d expect the middle of the curve people to be operating at. Individuals will peak at a particular point and will then progress slower. Realistically, most good people will peak at what I am calling a Staff engineer. Some will get frustrated with the leadership aspect of the senior grades and peak at Senior Engineer. The management ladder equivalence is also arbitrary, but should serve as a guide.

  • Junior/Associate Engineer/New College Grad – Assumed to know nothing, can code, have minimal understanding how business work and what a professional life entails. Hand held or teamed with a more senior engineer to help get an understanding. Career level 0–2 years.
  • Engineer – Assumed to be able to work through tasks with minimal supervision. Will come back and ask for more work. Not expected to identify and fix secondary problems. Not expected to drive generalized improvements or be strong advocates for best practices or improvements. Quite simply a “Doer”. Scope is typically at a sub-component level. Career Level 2–5 years.
  • Senior Engineer – Beginning to be self directed. Expected to be able to work through small projects and foresee issues that may come up. Likely expected to mentor or lead sub-teams or development effort. Scope is typically at a component or subsystem level. Career Level 5–10 years – equivalent to a team lead.
  • Staff Engineer/Architect – Runs the technical side of projects, leader and mentor for a team. Holder of a high bar for best practices, quality and engineering workmanship. Scope is across a system, or across multiple subsystems. Career Level 10–20 years – equivalent to a manager.
  • Fellow/Distinguished Engineer – Runs the technical side of an organization. Interlopes on many projects, defines the strategic direction for the technology. Career Level 15–30 years – equivalent to a director or VP.

It’s not about the code

Hopefully it becomes clear from the descriptions that pretty much from Senior Engineer and up, the technical role includes increasing amount of leadership. This is distinct from management. The leadership traits are about having your peers trust and understand you direction, being able to convince peers, managers and other teams about your general direction. Being able to deliver on the “soft” skills needed to deliver code.

Amazon’s Leadership Principles actually give a pretty good indication of some of the leadership needs for engineers.

There is a tendency for organizations to promote based on seniority or time in role, or even worse, based on salary bands.

Applying this to Yourself

  1. Ground yourself what your level means to you, the organization and your team. There may be three different answers.
  2. Introspect and ask yourself if you are demonstrating the non-management leadership aspects of a team leader or junior manager? Do you show confidence? Do you help lead and define? Do you demonstrate an interest in bringing in best practices? Do you see problems before they occur and take steps to manage them?
  3. Consider where you are in your career.

Your Career is a Marathon

A final thought, although you indicate a few years in the industry, I’ve seen engineers gunning for “Senior Engineer” 3 years out of college and staff engineer 3 more years after that. My big advice to them is what the hell are you going to do when you get to 6 years into a 40 or 50 year career and realize that you’ve peaked or you have some serious slow grinding for the next 20 years. I’m concerned about good engineers who become fixated on the sprint to the next title and not the marathon of their career.

Exploring Cognitive Engagement in Amazon’s Six Page Narratives

In a previous post, I discussed the Evil Genius of Amazon’s Six Page Narrative, exploring via a Quora post how the document is structured and why it works so well.  In Jeff Bezos’ Financial Year 2017 Letter To Shareholders, Jeff covers the Six Page Narrative and goes into the heavy polishing that a good Narrative provides.

In the Six Page Narratives that I have read, reviewed or discussed, I have always been frustrated with the tendency for authors to not use standard mechanisms to ease the cognitive load of the reader.  For example, below is a typical paragraph that you might find in a Six Pager.

Based on our review of the customer surveys, we can see that the US has customers preference as Product A – 10%, Product B – 40%, and Product C – 20%.  EU interest is Product A – 20%, Product B – 50%, and Product C – 10%.  Finally, JP customers have a preference of Product A – 40%, Product B – 20% and Product C – 15%.   Consequently, we will be focusing on Product A and Product B.

To me, this is clearly tabular data that should be structured in a way that walks the reader through the data providing support for the argument.

Geographic Region Product Preference
US 10% 40% 20%
EU 20% 50% 10%
JP 40% 20% 15%

As can be seen, there is a clear worldwide preference for Product A and B.

It is clear that with the narrative format, the information needs to be pulled apart by the reader to clarify and confirm the conclusion.  In the tabular format, the information is presented for simple confirmation of interpretation.

It has always felt to me that the narrative form is unfair and unsympathetic to the reader, forcing mental gymnastics where the gymnastics should not be needed.  In my own writing, I have always found the decision to tabulate vs narrate is a decision primarily based on the information density and valuable space consumed where in some cases every line counts.

Recently, I read Thinking, Fast and Slow.  In this book, Daniel Kahneman gave me that lightning bolt answer to what had vexed me about Six Page Narratives so much.

The Six Page Narratives are typically consumed in Amazon’s infamous Reading Meetings, where you have a number of senior leadership people who take the first 10-15 minutes of a meeting to read a Narrative or PR-FAQ, before discussing.  The senior leadership in these meetings are generally very smart and have years of experience. You want these leadership team to be engaged in reviewing the document and surface areas that the author and their supporting team may have not considered.  You need the reader to be cognitively engaged to be able to successfully provide that extra input.

According to Daniel Kahneman’s book, when a reader is having to do cognitive work to consume some information, they will typically think deeper and more broadly than if they were presented the information in a way that lowers cognitive load.

Assuming that Thinking, Fast and Slow is correct, it puts the onus on the author of a narrative to make a conscious decision as to where that knife edge is between getting reader to think through the problem, possibly gaining deeper insights, or to present the information and allow them to be taken on the cognitive easy course.  Or put slightly differently, how to make the choice between engaging a reader, or simply informing them.

Finding a Product That People Will Buy

This, of course, might be my fatal flaw.

The product I’m creating is a competition to the humble Enamel Pin, but better.  Our products are different but in a good way. 20171022112223_235x

They are full color (with minimal limitations on color), scalable from single badge to 1000 badges.  The image to the right is a series resulting from a collaboration with a designer, Alyssa Harris, a young designer from Idaho.  As you can see, they are full colors, random shapes and can look pretty damn cool.  Due to the manufacturing method I’m using, and the back end code that I use for generating the badges, I can scale pretty easily based on fairly simple input.

The closest analogy to this product is the enamel pin.  These are lapel pins that are carved/stamped out of metal and then painted to give the color.  These have been slowly gaining popularity for a year or two. There is a large number of the pins on Aliexpress, and so within the Pin community there is a hell of a lot of Rick and Morty pins going around.  These are exactly the same pins.  Emojis are also extremely popular due to the familiarity and generally free artwork.   There is a growing number of kickstarter campaigns where people crowdsource funds – sometimes thousands of dollars to get the first batch done.  Now there are also a lot of absolutely amazing designers and pin collaborators out there.

Soft enamel pins seem to have stabilized at around $9-12 retail.  So that would tell me that somewhere in the $7-10 range would be reasonable – if the financial side maps up.

So how is Badgly different.

  1. These don’t need to only be pins.  Since they are an unfinished blank when we receive them I’ve settled on pin backs for pins, or magnets.  This allows the same design to be used for Lapel Pins on leather jackets, pinboard pins, hat pins.  The magnet form can be for fridge magnets, cubicle magnets or lockers.  So I’ve got a fairly broad set of applicable options.  On Badgly, the purchase options for all designs is either magnet or pin.  I currently don’t differentiate on price since either one comes down to a few cents.
  2. There is no metal, the badges are made out of sandstone, so they are considerably lighter.  A design for a typical enamel pin will usually have the walls in the design, where the metal prevents colors from mixing.  For the Badgly pins there is no wall, you can have colors right alongside each other without needing any separator.
  3. Since we don’t have a die to cut, a single badge is effectively no more expensive than 100 badges.  For custom designs, this makes the difference between a $15 purchase and a $150 baseline purchase.
  4. Designs are easy.  In the simplest form, it’s an image to simple 2D badge.
  5. 3D. Badgly pins can be 3D, in the simplest form each individual color can be raised or lowered to different heights – providing a very unique experience.
  6. Contoured 3D.  Beyond the straight 2D extrusion, Badgly pins can have any 3D contours you’d like. This is similar to 3D cast pins.  3D cast pins have an entry cost for about $200.

Head over to and tell me what you think.

The Long Slow Path to E-Commerce

I’ve had Badgly open for about 2 months now.  Traffic is slowly building, but as is typical in Shopify stores bootstrapping themselves and coming from nowhere, I haven’t made a sale, yet.  I’m actually completely fine with that for the moment, since it allows me to understand what is going on before I feel I am risking customers.

My understanding of the who e-commerce growth aspect goes something along the lines of…

  1. Have a product that people want to buy
  2. Have a website that organically ranks for people looking to buy.
  3. Invest in social media to grow a following
  4. Invest in advertising to get more people

That, of course, sounds very simple.  Now particularly with drop shipping, there are many thousands of stores that throw a nice face on a product using stock photography, market the hell out of it and as orders come in pass them off to a wholesaler who does shipping and other logistics.  In theory a nice little opportunity for some relatively passive income.

I’m not in it for that.

Based on some experiences previously, I’m creating pins, badges, and magnets using full color 3d printing, finishing by hand.  These are more or less in direct competition with enamel pins, but I’ll get onto that later.  So let’s pull apart my assumptions above and see where the lead.

So next post… the product…

This is a post that is part of me documenting my experience building the Badgly store.  All the articles are grouped together under the Badgly Category.

Learnings from an Online Store

I’ve recently opened an online store for Pins, Badges, and Magnets using 3D Printing technology.  The store is called Badgly and is at go there, the link to the left has a 10% off discount applied. They are mostly equivalent to Enamel Pins, but don’t have the high upfront costs of creating the die and manufacturing them.

As part of this journey, I’ll be documenting my experiences with Shopify, Adwords and building an online presence.  I’m not going to guarantee that my assumptions will be 100% correct, but I hope that my experiences will help others going through the same process.

All the postings will be under the Badgly category.  Feel free to post comments, corrections or insights below.  Some of these posts will be cross-posted to Badgly, depending on the contents – on, I’ll be a lot more open about the frustrations, machinations, and pain that goes into building an online presence.

Meltdown and Spectre Computer Vulnerability Cubicle Magnets

When something bad happens, like Meltdown or Spectre, or Heartbleed, your engineers end up having late nights,  grueling daily update meetings.  At the end of the day when the dust settles, we don’t get a Service Ribbon that shows your involvement in those days of battle.

With the security industry creating well-recognized brands and logos some of the bigger vulnerabilities, we might have those opportunities to make sure those that join the firefight get the tech equivalent to the service ribbon.

At Badgly, we’ve created some cubicle magnets that allow for a commemoration of those days when you lots lunches, nights and weekends to solve some of your companies biggest and burning issues.  We’ve got a set of Vulnerability badges for Meltdown, Spectre, and Heartbleed.  We’ll update this post with images when they get back from the printers.  Some sample renderings are below.

For geekiness points, all the vulnerability badges will be golden-ratio rectangles.  Is there a vulnerability that you’d like to see memorialized?  Post comments below.