Planning for the first road trip in the Model S



Before taking delivery of my Model S I had some range anxiety, but since taking delivery it has rarely come up. I charge daily to 90% in my 85 kWh Model S and drive about 100 miles a day commuting, running errands, etc. I return home with about 140 miles of range left every day which is enough to do it all again without charging. There have been a few longer round trips where I did about 180 miles round trip, and one intentional (but not required) visit to a Supercharger, but none of my trips have required charging en-route or destination charging.

As the end of the summer approaches I have two road trips coming up. One to NJ, about an hour east of NYC, and another to PA about an hour northeast from Pittsburgh. The NJ one is this week and is the subject of this post. The PA one is the subject of a future post.


EVTripPlannerThe first thing I did was look at the distance. There are a few routes that I could take but the travel distance is about 244 miles. If I range charge i’d have 265 miles of range but those are rated miles which are not the same as actual miles. Your actual mileage may differ from rated mileage due to terrain, traffic, air conditioning, pit stops/detours etc. These numbers were close enough that I was already convinced i’d need to charge along the way and that wasn’t a big surprise to me. I also needed a safety margin.

Recommendations for a safety margin vary. Here are 3 popular options and what I would be able to use if I started at a 90% charge of 240 rated miles:

  1. A fixed amount: 50 miles – Can only use 190 rated miles
  2. Only plan on using a fraction of rated range: 2/3 – Can only use 160 rated miles
  3. Maintain a safety margin percentage: 25%  – Can only use 180 rated miles

So somewhere between 160-190 rated miles i’m going to need to charge. I could stretch that a bit with an initial range charge if needed.

Note that all these safety margins are pretty conservative and experienced owners cut these margins way down and/or vary their margins based on the time of year/weather.

Next I looked at Supercharger locations along my route. There are a many ways of doing this, i’ll just mention two:

  1. Google maps – Enter your start and end addresses and then type “Supercharger” and have Google find Superchargers on the map along your route. Pick a good one (or more if needed) as waypoints.
  2. – This is a cool site put together by an enterprising 16 year old. With this site you enter your start and end addresses and some car information and click the “Route through Superchargers” button and it gets you to your destination through superchargers. Its not perfect and it can add more stops than needed so check the work and adjust as needed. One great benefit from the site is it predicts how many rated miles you will use and reports both actual and rated miles used.

I used EVTripPlanner and found that while it wanted me to hit the Milford, CT Supercharger and the Darien, CT Supercharger, I would have plenty of range to skip the Milford, CT Supercharger. From my home to the Darien Supercharger its 147 miles and the tool estimates 161 rated miles needed. That’s well within the most conservative of the safety margins above starting with a 90% charge.

From there it was only 93 miles to my destination or 102 rated miles estimated and no more charging would be needed to get there.

But the planning doesn’t stop there.

How much to charge

IMG_2598With an ICE car, when you fill it up it fills quickly, doesnt really slow down as you fill and generally you fill it all the way. EV’s are different. EV charge rates taper off quickly as they approach the 100% mark which can add significant time to your charge. Also EV’s charge faster from near empty than they do from half full.

When you look at charge times and rates on Tesla’s site, those are generally ideal conditions with a perfect Supercharger to current specs, nobody sharing a portion with you and charging your car from empty. You will likely need more time to charge than those estimates.

So from the section above, I start with 240 rated miles on a 90% charge. I drive to the Darien Supercharger and use 161 rated miles. I have 79 miles of rated range left. Not enough to get me to my destination and the reason for my stop. The planner estimates 93 miles needed with no safety factor. Safety factors are generally added to standard (not rated) mileage. I need to add some safety factor so lets take the 2/3 approach. 93 x 3/2 = 140 miles of rated range needed to arrive at my destination. So I need to add 61 miles of rated range at the Supercharger to get to my destination and have a good safety margin.

Sometimes you may need to charge more than you think – plan for the return.

Tesla claims 170 miles of rated range added in 30 minutes, but as we’ve mentioned they’re overly optimistic with this. Even so, planning for a stop of about 30 minutes is very reasonable and thats after driving for a couple hours.

So i’ve got myself there with a safety margin with a short Supercharger stop along the way, but i’m still not done.

Destination charging

ChargepointUnlike our homes as EV owners, our destinations will rarely have a decent charging setup. Unless you’ve “gifted” charger setups to the people you’re visiting (several have done this), you’re likely to find some pretty poor charging infrastructure at the destination.

In my case as far as I know the best i’ll see at my destination will be a standard 110V 15A plug that provides about 3 miles of rated range per hour. I’ll definitely poke around when I get there to see if I can find a better outlet that I can reach, but I need to plan for the worst.

If I charge the minimum at the Supercharger to get to 140 miles of rated range, drive and use the estimated 102 miles of rated range i’ll arrive at my destination with 38 miles of rated range left. On the way home I need to go back the same route and I need that 140 miles of rated range for the distance plus safety. Oops — I can’t get home.

Destination charging is important.

So I need to add 102 miles of rated range while i’m there. More if I plan on doing things with my car while I’m there like showing it off with test drives, going to dinner, etc. Lets say I need 50 miles to use while i’m there, plus the 140 to get back to the Supercharger. I need to add 152 miles of rated range. At 3 miles/hour thats 51 hours of charging. For a 3 day weekend it almost means I can’t use the car while there as it needs to be juicing up the entire time.

So now I had to look at options:

  • Find a Supercharger near my destination – NJ only has one and its more than an hour away. No good.
  • Find a faster charger nearby – A local college has a J1772 reported at 30A/240V which would give 18miles rated/hour added. But i’d have to leave my car there or sit there for the charge. Better, but not great.
  • Charge more at my Supercharger stop on the way down and arrive with more left.

The best option seemed to be stopping a bit longer at the Supercharger on the way down and charging up more. I’ll charge back up to 90% (240 rated miles), use 102 rated miles to get to my NJ destination and have 138 rated miles left. If I don’t go anywhere while there that’s plenty to get back with a safety margin. If I want to drive around while i’m there I only need to charge enough for that. I figured about 50 miles, so thats only 16 hours of charging or 2 decent nights. That’s doable.

Planning Complete

Supercharger Map 082014If I did my planning well the return trip will be uneventful. That’s because I thought about the return before I started the trip. If I had only planned for the trip down it could have gotten trickier.

Another angle to consider is detours along the way. On our way down to NJ we have a favorite Sushi place we like to visit in CT. Thats a bit off the route and will add a couple miles. Being the planner, I also looked at the case where the Darien, CT supercharger was offline/broken when I arrived. What would I do? Fortunately there’s another one on the Northbound side of I-95 and then more only a few miles away on the Merritt parkway in a pinch. Unlike MA and NJ, CT is pretty blessed with Superchargers!

This will be my first real EV road trip. Next to the the epic 12,000 mile trip taken by the Recargo folks and many other road trips that are happening daily this is a tiny and simple trip. For me, as a new owner and still struggling with range anxiety, its been eye opening thinking about the options and things I have to consider that I never once thought about in an ICE car. With an ICE car I drove until I needed gas and then it was easy to find and fast to get. With an EV a little more planning is needed, but thanks to the growing Supercharger network “filling up” my EV along the way is a minor inconvenience.

Oh, and did I mention that the Supercharger use is free?


EV Basics – Whats a kilowatt hour?



EV Display UnitsAs many of us take the plunge into the joys of owning an electric vehicle we’re exposed to some terminology and measurement units that we may not be very familiar with. What is a kilowatt hour? How does it differ from a kilowatt? Why do I care?


First, let me say that some of this may be specific to the US in terms of the units we see on bills, on our dash, and on our bills. Most drivers in the US have their units set to miles vs km and so far we’re all still paying in US dollars. I’m also over simplifying all the science in this to get to the basics so please cut me some slack if you already know all this!

We all should probably already be familiar with kilowatts (kW) and kilowatt hours (kWh) because our electricity bills are reported in kWh. Your EV is using units that have been on your electric bills for years so this terminology and unit of measurement is not new to us but may be something we haven’t paid much attention to in the past.


Depending on the EV display you may see watt hours (Wh) or kilowatt hours (kWh) in some places and watts (W) and kilowatts (kW) in others. The kilo or k is a standard prefix meaning a thousand. So 1 kWh is 1,000 Wh. If you own your EV long enough you may just get to the next level, megawatt hour (MWh) which would be a million Wh!

Now for the fundamental definitions:

kW is a measurement of power and kWh is a measurement of energy.

Energy is about how much fuel is contained in or used by something over a period of time. kWh, calories, joules and other things like that are all units of energy and you can convert between different units. A slice of pizza has 285 calories which is 0.33 Wh of energy. Energy can be converted and change form. We can convert that slice of pizza to heat by burning it. The fuel is the pizza, but don’t try converting it in your EV!

Power is the rate at which energy is generated or used. kW is a unit of power. When you accelerate you’re using power and when you decelerate with regenerative braking you’re generating power. The Model S dedicates half the speedometer display to the unit of power on the right side. There you can see how many kW you are using (indicator is orange) or generating (indicator is green) at any instant in time. This is good to see, but you can’t easily convert this into cost — for that you need to measure it over time to convert it into a unit of energy.

Power is similar to your speed. 50Mph is your speed, but you have to maintain that for an hour to go 50 miles. Similarly, 40kW is how much power you’re using but you have to do that for an hour to use 40kWh. If you spend half that hour at 40kW and the other half at 20kW you’ll end up using 30kWh. Power usage is constantly changing and will also include things like your heater or A/C use.

Energy is power over a unit of time.

As another example, a 100W (100W of power) bulb used over 1 hour is 100Wh of energy used. If you use that 100W bulb for 8 hours every day, it will consume 0.8 kWh per day. After 30 days, it will have consumed 0.8kWh x 30 = 24 kWh. After 365 days it will have consumed 292 kWh. Your EV is the similar but it can both use and generate power over periods of time. The difference or net power used (used – generated) is what you see reported on your EV displays.


EV Charging Units

When charging your EV you’re loading energy back into your battery so you’re storing kWh for later use. EVs report charging in different ways. The natural way to report charging is kW and kWh added. So a charge rate of 6 kW is storing 6kWh up for every hour of charge. If you’re adding at 6kWh/hour and charge for 2 hours you’ll have an extra 12kWh added at the end of your charge.

While we like to think in terms of miles, not all miles are the same and there are hills and weather and other factors that vary for each mile. A kWh stored is always the same — it comes down to how you use it. This is why the purists show and measure kW and kWh for charge rate.

Purists show and measure kWh for charge rate.

The Model S offers the kW and kWh display option, but many owners choose to display charge rate in terms of miles of range added per hour, i.e. 16 mi/hr. There’s an assumption being made here about how many miles you can drive on a Wh and that assumption needs to account for charging efficiency. Tesla uses different math for this conversion depending on the situation.

Tesla varies charging efficiency assumptions in different situations.

In Tesla’s online calculator they assume 300Wh/mile average use and a 90% charging efficiency. My own measurements show the average Wh/mile usage to be bit higher (306 lifetime average) and the charging efficiency to be a bit less (81% last month).

Now you may be wondering how all this relates to volts and amps. This gets us back to the basics. Given volts and amps you can calculate watts by multiplying the two together. W = V x A. So if you’re at a public charger and its charging at 199V and 30A like the picture above, you’re charging at 199V x 30A = 5,970W or about 6kW. That doesnt mean you’ll have 6kWh added after an hour of charging as charging efficiency needs to be factored in.

The Model S is reporting this as a rate of 16 mi/hr. Lets check that math:  5,970W/300Wh/mile standard assumption = theoretical 20 miles/hr charge rate. But that doesn’t account for charging efficiency. The Model S is reporting 16 mi/hr so its assuming an 80% charging efficiency (16/20) under these conditions.


Electric Costs UnitsOn your electric bill, costs are expressed in price per kWh. So $/kWh. Your electric company may break it down by distribution vs generation, time of use, etc. and then have a different cost per kWh on each and the pricing seems complex but you can simplify this.

To figure out your total cost per kWh just take your total amount for the bill and divide by your total usage for the same period. That does include the various service fees, taxes, etc. but in the end you’re paying the electric company that total amount for those kWh you used however they’re adding it up. This average rate varies greatly throughout the country and world.

When you have those averages you can look at your kWh used on your EV and calculate the costs for your trips etc. But beware of those charging efficiency losses.


EVs display all the usual numbers you’re used to like miles travelled, speed you’re traveling, etc. But they also report how much power and energy they’re using. Power is like your speed and energy is how fast you’re using or regenerating power. Added to the complexity are the various differences in charging stations in volts and amps provided and then the conversion factors and efficiency losses in converting back into power and energy.

While there are a number of terms and a few simple formulas to get used to, the average EV owner often ends up better informed and more aware of the actual costs of driving and energy usage than many drivers of gas powered cars. Thanks to the extra information, EV drivers often drive more efficiently than drivers of ICE cars — even in powerful cars like the Model S.

EV drivers often drive more efficiently than drivers of ICE cars

Infinite Mile Warranty


Infinite Mile WarrantyThe big news today was that Tesla announced that the Model S drive unit warranty has been increased to match that of the battery pack. For those of us with the 85 kWh Model that means it  now has an 8 year, infinite mile warranty on both the battery pack and drive unit. Not only did Tesla do this for cars they’ll be making in the future but they made it retroactive to all 85 kWh cars they’ve built.

Yep, I just got a warranty improvement on my drive unit.

Original Warranty

Owners will find Warranty information in the “Quick Start, Roadside Assistance, Safety, and Warranty” document on the “My Tesla” portal. These docs don’t seem to get updated so my original warranty is still there, but with this new announcement its been superseded in part by the announcement.

Before the announcement the warranty had multiple warranty conditions:

  • Basic Vehicle Limited Warranty
  • Supplemental Restraint System Limited Warranty
  • Battery Limited Warranty

Since the drive unit was not called out specifically, it would have fallen into the Basic Vehicle Limited Warranty which provides for coverage of the drive unit under normal use for a period of 4 years or 50,000 miles (80,000 km), whichever comes first. For me that would have been less than 2 years of driving.

New Warranty

While we haven’t seen the official “legal” warranty terminology, its likely to be something like “Battery and Drive Unit Limited Warranty” where the same 60kWh vs 85kWh language is included as well as the limits:

  • 60 kWh – 125,000 miles (200,000 km)
  • 85 kWh – unlimited miles/km

I’ve previously heard comments that the drive unit should be able to do about 500,000 miles, but a number of very high profile drive unit failures have people concerned. Elon has come out and said that a good number of “drive unit failures” were not actually failures but overly conservative service people doing their jobs to do the best for the customers. In many cases a simple $0.50 strap would have done the trick.

Elon’s answer to all the FUD surrounding drive units and how long they’ll last? The unlimited mile warranty.

This is brilliant. Obviously Tesla has studied this problem and knows if its real or not. They also know the true quality and life of the drive units which is far beyond what most people could possibly drive in 8 years. So in one quick stroke Tesla squashed the main concern — what will a drive unit cost to replace when the original 50,000 mile warranty runs out?

Even with my high mileage, I won’t get to half of the estimated 500,000 miles the drive unit should really be able to do and now I no longer need to worry about mileage on my battery or my drive unit. 8 years is a long ways off and I usually replace my cars after 200K miles/7 years.

As they’ve done with every aspect of building, selling, and servicing the car they’re changing the way warranties are done. What would our world be like if more companies behaved as responsibly and quickly as Tesla?




New Summer 2014 Tesla Model S features


I ordered my Model S in March 2014 and took delivery at the end of April. I saw some posts recently about some changes to the Model S and collected the list of things that changed in the Model S in the last few months.

Color Change

I went with the “Grey Metallic Paint” color and absolutely love it. Some people call this “Dolphin Grey”. Tesla just changed the definition of “Grey Metallic Paint” for some reason and now its a darker grey. I haven’t seen one in person yet and would love to line mine up next to the new color. From what i’ve seen and heard i’m going to like the original/lighter grey better.

Grey is the new black.

Below is the best comparison picture i’ve found with the one I have on the left. The grey on the right is very dark and almost black.

New Grey

Interior Changes

Headliner DashThere’s a new option on the order page that separates the Alcantara headliner from the Alcantara upper dashboard trim. The second option is new but doesn’t change the price and requires the Alcantara headliner.

I wasn’t interested in the headliner, especially at $1,500, but I find it interesting that they thought it important enough to break this out as an option.

Another interesting change is the parcel shelf was an extra charge ($250) when I bought my car and it’s now included for free. I would have liked it for free but it wasn’t worth paying for to me.

It would be nice if Tesla offered this shelf to current owners for free when they did an annual service. Right now it remains a $250 purchase post-delivery at the Tesla accessories store which is just a silly price for it.

Feature Change

On the Tesla Motors Club forums there are reports of a new feature available on new deliveries, an Ionizer:

IonizerIonizers reportedly clean up particles that get in through open windows and doors. They emit positive and negative ions that attach to airborne bacteria, viruses and molds, theoretically neutralizing them. Toyota and Volvo among others offer this in their higher end cars. There are those that disagree that ionizers are beneficial though.

New owners are reporting seeing this new feature available on their cars when running v5.12 of the firmware and its not something that is an option during the ordering process. According to the reports there’s extra hardware in the car to support this so I don’t think existing owners like myself will magically get the ionizer when they get updated to 5.12 and the reports on TMC seem to confirm that.

Ionizers can easily be added to cars without this feature though. You can buy one for about $15 and plug it into the 12V outlet. Amazon and many retailers have many options to choose from.


Tesla continues to quietly evolve the options and configurations of the Model S. I wish Tesla had an owners or private newsletter to keep us informed of the advancements and changes and how things may or may not affect existing owners. It will be interesting to track the features and price changes over time and see how the Model S grows up. While some of the changes above would have been nice to have, i’m a very satisfied owner without them and have zero regrets.

5 tips to maintain your EV battery


Battery Pack innardsElectric Vechicles get us independence from gas and gas prices and remove all sorts of unnecessary engine parts, noise and maintenance. But they also bring in a new technology with advanced Lithium-ion battery packs that need some special handling.

Here are the top 5 things you can do to extend the life of your battery:

1. Never charge your battery to 100% and let it sit.

Most EVs have an option of a “Standard” charge or a “Range” or “Max” charge. By all means, do the maximum charge when you need it, but do it right before you start using the battery for the trip. Most EVs have charge timers to help you plan for this. If your EV doesn’t have that, do an overnight standard charge and then charge the last 10-20% in the AM before departure. Leaving a battery pack at max charge for even relatively short periods of time can reduce its life. As a rule of thumb, try never to let your battery sit at maximum charge for longer than 8 hours.

2. Never let your battery sit at a very low charge state for an extended period.

Leaving your battery in a discharged state for an extended period will also reduce its life. Most vendors protect batteries from becoming completely discharged as that can effectively “brick” the battery to make it completely useless. The general rule of thumb is to plug in and charge whenever you can. That doesn’t mean going out of your way for a few kW of charge, but it does mean plugging your car in nightly and maintaining a reasonable charge level.

What is a low state of charge? Under 30% charge is generally considered low and a state that you should probably not let your car sit in for an extended period. Also beware that EVs lose charge state even when they sit unused. With the Model S, it loses about 1% of its charge per day.

3. For daily use, charge to your vendors 90% limit or less

While you may be able to time your max charges and departure times well, daily charging to 100% is stressful to your battery. This is why most vendors offer “standard” or “normal” charge levels that don’t provide the maximum range quoted for your vehicle. If you don’t need the max charge then don’t use it. Generally lithium-ion batteries do best when they operate in the 30% to 90% range for state of charge. Much time spent above or below that range will lead to a shorter pack life.

4. Don’t store your EV fully charged.

If you’re going away on vacation or for a business trip the best thing for your car is to set the charge level to 50% and leave it plugged in. If you’re leaving your EV at the airport or somewhere where you can’t leave it plugged in beware that you’re going to lose some charge per day. Charge to a level where you can get to the airport, let it sit for the trip and then still have charge and margin to get home. Don’t let it sit for days at the airport at a 90% charge state if you can avoid that. Still, sitting at 90% is better for the battery (and you) than sitting at 10% and coming back to find the battery completely discharged.

5. Periodically fully charge your battery.

While lithium-ion batteries are designed to minimize the “memory” issues of older technologies, battery packs in EVs are more complex and are often comprised of multiple individual batteries — as many as 7,000 cells in the Model S. Battery balancing is about maximizing your battery’s capacity to get full capacity out of it increase the battery’s life by evening out the charge distribution. Modern EV battery packs include a automatic battery balancing component, but you can help too. While you may never need the maximum range that your battery can provide and you may never take long trips, a periodic range or max charge is helpful to your battery’s management system. I’d suggest doing this about once every 3 months or so and keep in mind that after you fully charge you should not let it sit, that would be a violation of battery management rule #1.

Disclaimer: Since we’re dealing with expensive components and i’m no expert I want to point that that fact. Read the manuals for your EV, search your EV forums, develop your own rules and be consistent and adjust as needed. The rules above are general rules for any EV that will likely extend the life and health of your battery but your own mileage (range!) may vary.

Should Model S owners be concerned with their battery pack version?



Prior to and since delivery i’ve heard discussions on the Model S battery packs and A vs B versions and various owners concerned about which battery pack they have. I did some research to better understand what’s going on here.

Battery Pack Information

The first place to start is by getting your battery pack information. There’s a sticker on the battery pack under the car that is visible from just behind the front right (passenger side) wheel. The sticker (mine), looks like this:

Battery Pack ModelThe first and most important part of this information is the size of your battery. You can figure this out by looking at your range too, but its another good confirmation that you got the battery that you ordered. The next piece that has any potential use is the model of the battery. Thats the last letter at the end of the part number. So for the case above, this is a D battery pack.

Battery Pack Differences

The main difference between battery packs has been reported between the A and B battery packs. An improvement to the cooling system of the battery pack was made starting with the B packs that allowed for faster Supercharging. Those with A battery packs can only Supercharge at a maximum of 90kW while those with B battery packs and later can Supercharge at 120kW or possibly higher.

TMC has a Wiki tracking the battery part numbers and the basics are as follows:

  • 1014114 is a new 85 kWh pack
  • 1020422 is a new 60 kWh pack

There are also other part numbers out there and the community hasn’t yet nailed down what they designate. Some part numbers may be refurbished versions versus new versions. Just recently KmanAuto had a battery pack replacement on his 60kWh Model S and he got a part number not yet on that Wiki page which may indicate that it’s a refurbished 60 kWh pack.

Barring formal information from Tesla, the working theory is that the battery pack versions A, B and D, are the equivalent to model years in some cars — they’re evolutions of the same thing and each is better than its predecessor. Superchargers capable of greater than 120kW are just starting to pop up. The 100th Supercharger, recently installed in NJ, was a 135kW Supercharger.

From the forums, D batteries began shipping sometime in the second half of 2013 and are still the latest ones being installed. If you have a D pack you’ve got the latest.

If you have a D pack you’ve got the latest as of the Summer of 2014.

So far there have been no reported experience differences between the B battery pack and the D battery pack in terms of charge rates or performance but the current theory is that the B pack may be limited to charging at 120kW while the D pack may be able to go to 150kW when Superchargers support it. While the C pack was mentioned many times I never found a report of anyone with a C pack.


Despite opening up their patents, Tesla battery technology is a pretty much a mystery to most. While not necessarily the most efficient on the market, Tesla does have a lead in the size of the batteries and their Supercharger network and charge rates are an important key to Teslas success. Tesla is not forthcoming on the capabilities of the various versions of its battery packs and leaves its user community (and even Tesla Service personnel) to figure out what they can and can’t do with their battery in terms of charge rates, charging profiles and other attributes.

At a Supercharger your charge rate will vary due to a number of factors. One may be related to your battery pack, but more likely it will be related to the limitations or current state of the Supercharger or if you’re sharing a section of the Supercharger with a fellow Model S owner.

If you bought a Model S in later 2013 or 2014 you’re most likely using the latest and greatest battery from Tesla. Should things ever go wrong with your battery you may end up getting a replacement one. There have been reports of older “A packs” being used for refurbished parts which could lower your Supercharging rates. You do not want a replacement pack that is older than the one you had and the Service Centers don’t appear to be stopping this from happening. Just to be safe, check your battery model and version and take a picture for your records.

Check your battery model and version and take a picture for your records.

Model S Navigation Controls


In a previous post we covered the Model S map and navigation displays. In this post we’ll focus more on the navigation controls Tesla provides for the Model S. Only those that elected to get the technology package (about 85% of owners) get turn-by-turn navigation and navigation controls.

Searching for Destinations

Best Nav SearchSetting a destination comes down to one of three approaches:

  1. Voice Search
  2. Typed search
  3. Pick from your Places

Before you ignore the voice search option like I did when I got my Model S, let me tell you that the voice search on the Model S is the best i’ve had on any device. It’s got the power of Google’s voice recognition behind it and the full Google maps database so it’s incredibly good at understanding and finding what you’re looking for. It’s so good that even with complex names or places I always enter directions by voice even though I generally shun voice commands on all my other devices. It saves time and is much faster and safer than trying to type in the search items.

The voice search is the best i’ve had on any device

To activate voice navigation, press and hold the voice command button on the top right of your steering wheel and ask “Navigate to” or “Where is” or “Drive to” and then the rest of your command and then release the button. A very common early owner mistake is pressing and releasing the button before speaking.

A very common early owner mistake is pressing and releasing the button before speaking.

Note that “home” and “work” are special words that use your designated home and work addresses as the target destination. The “to” part is optional as well so you can just press and say “Navigate home” to always get home from wherever you are. Even simpler than trying to click your heels three times. As a special bonus, if you haven’t set your home or work address, the Model S will detect frequent stops and suggest that you set your home or work address for future use.

The other search approach is to type your query into the search box. Like any tablet the big keyboard pops up and you can enter any terms you want. If, somehow, the voice recognition got things wrong or you want to modify a pre-existing search you can do so here.

When searching for destinations you can be specific and ask for names, you can ask for street addresses, or generic categories. I’ve tried all sorts of different options and always had great success with it. In the search below I asked the system to find a Japanese restaurant:

IMG_4326If only one result is found it will immediately start navigation to your location (most notably with the “Navigate home” type command). If multiple results are found they provided in a scrollable list sorted by distance to travel. Pressing on any of them will immediately start navigation to that destination. If your map zoom level allows it, the possible destinations are also shown on the map and you can press on any of those to have extra controls like marking them as a favorite, or calling the destination if it has a phone number. It would be nice if you could inspect possible destinations from the search list rather than having to find the icon on the map.

Saved Destinations


NAV DestinationsThe Model S has a fairly rich set of saved destinations accessible from the “Places” button. This area not only lets you save favorite locations and set your home and work addresses but also saves recent locations and searches which is really convenient. Thoughtfully they let you remove individual destinations from your history or searches with the edit button in case you had a top secret meeting somewhere. Note that in all these pages edits are individual operations. You can’t clear ALL your searches or favorites or destinations nor can you delete multiple at a time.

The favorites section of Places is the most broken and dysfunctional. At the top home and work destinations always appear. After that its a list of all saved favorites. The order they’re presented in is undecipherable. It is neither alphabetically, distance or recently used sorted. As such it makes finding a favorite a real pain. Also, unlike my old MDX, you can’t create categories for your favorites (folders if you like). I used to have categories like “Doctors” or “Kids”. Because of how broken this part is I rarely use and resort to the recent destinations as a more useful option.

The favorites section of Places is the most broken and dysfunctional.

Helpfully, Tesla has included all Supercharger locations in its own section and this is logically sorted by distance from your current location. This is a great and useful addition that i’ve only unfortunately enjoyed once since there are no Superchargers in my state. For traveling this section would be invaluable and I hope that Tesla keeps it current as Superchargers continue to pop up around the country.

The final section of places is Visited Charges. This is where you’ve gotten a charge from in the past. When you’re low on power and need a familiar place this would be helpful. One thing I thought was cool is that there’s a place my care reported itself being charged in California — its first charge. How special! Another charge location it recorded is the delivery center in Watertown, MA along with the usuals of my home, the Tesla Store at the mallthe public J1772 charger I tested etc.


With most navigation systems this would be the section where we’d discuss routes and alternate routes, traffic based routing, finding alternate routes, waypoints, preferred road types and all sorts of things most people take for granted in modern Navigation systems. My 2007 Acura had all of that. The Tesla has no routing options at all.

Once you start navigating it does it’s magic to get you there. The routes it picks are decent in terms of map routing. It will also do the basics of re-routing if don’t follow the directions, but that is all it can do. Even GPS systems that sell for less than $100 can do better than this and routing is the most disappointing area of the Model S navigation system.

Routing is the most disappointing area of the Model S navigation system.

Owners have been clamoring for the basics to be added since the Model S started deliveries, but for some the expectations are even higher than that. Model S owners want routing that takes into account the state of charge (SOC) of their battery, terrain, weather, possible charge locations along the way, etc. That may all sound complex, but it’s something an enterprising 16 year old has put together on his own. Why can’t Tesla do this?

Once guidance starts the directions are shown on the 17″ screen and the dashboard display and as we’ve covered previously the display part of routing and navigation is well done.


NAV SuperchargersThe Model S has great options and ability to find target locations to navigate to. It has some weaknesses around managing favorites and a few other small things that would be nice to have.

The glaring omission in the Model S navigation system is around routing options and abilities. In my old 2007 Acura I used waypoints all the time, mostly to get me around known bad areas or traffic and then to get back on track. With the Model S doing the same thing is much more cumbersome and, frankly, unsafe. If you’ve spent any time watching Tesla videos from the popular people like Bjorn Nyland in Norway you’ll find that most have a second GPS system stuck on their dash to fill in for the huge limitations of the Model S’s navigation system.

It is a shame that a navigation system with so much promise and raw capability is so limited in what it has delivered to the owners and this is the main promise of the 6.0 software update that has been promised for many months. Will the 6.0 update address all the navigation shortcomings? Will it also go beyond and bring capabilities that no other car navigation system on the road today provides? Elon has hinted it will do the latter. Meanwhile most of us are just hoping to get on par with other systems as soon as possible.

Super-advanced navigation would be nice, but most of us are just hoping to get on par with other systems as soon as possible.

Elon, are you listening to your customers?

Model S Navigation Displays


By now I was hoping to be reviewing the Navigation updates that Elon has been promising are coming in the 6.0 firmware update for the Model S. But after watching 5.9, 5.10, 5.11 roll out over several months without the NAV updates we may be living with the current system for a bit longer. The current NAV system is not bad and does have several great features to it, but it could be better and is below par for the industry in several areas.

Tesla’s navigation system is below par for the industry in several areas, but it does have several great features.

In this post i’ll cover the displays and their use and in a follow up post i’ll get into more details around navigation.

Google Maps Display

NAV DisplayThe most obvious and frequently pictured portion of the Model S Navigation system is on the 17″ screen where the map can be shown in either half screen (huge!) or full screen mode (mind bending!).

In half-screen mode you can put the map on the top or the bottom of the display. I prefer the map on the top as it keeps the map closest to the windshield and my eyes have to travel less distance from the road. I don’t find the map distracting and for me the viewing height in this position is very reasonable.

The map shown is a Tesla-modified and co-branded version of Google Maps. As you’d expect you can zoom in or out by pinching/reverse pinching or with the +/- icons. You can also drag to move the map around, you can twist to rotate the view and otherwise interact with the map. If you’ve used Google Maps on a tablet or smart phone its very much the same experience and the way maps should be experienced. Try moving around on a map with the arrow keys or big dial on a Mercedes or BMW. Those systems are tiny and archaic by comparison.

Tesla’s map is the way all maps should be experienced.

Like Google Maps, the Tesla version offers both satellite and regular map views. Press on the globe icon and you get a satellite view. This is really cool for exploring areas or understanding your terrain better. The maps are a little more sluggish in satellite view but are are generally only painful when you’re moving quickly and the map is zoomed out. One trick is to set the map in north up mode when in satellite view to reduce the number of screen updates and improve performance.

Set the map in north up mode when in satellite view to improve performance.

When in heading up view an extra compass icon appears on the map indicating which way is north. You can also tap that icon to switch back and forth between heading up and north up views.

The Model S has both day and night modes for its two displays. Beware that if you’re in the satellite view and the displays switch to night mode it will kick you out of the satellite view into map view — Google’s satellite pictures are all daytime pictures and the Tesla engineers thought you wouldn’t want to see that at night. I would have preferred it just left the daytime images or that they would have made that an option. If you want the satellite view back on at night you just have to re-press the satellite view icon and you’re good for the rest of the night.

Also like Google Maps, there’s the ability to show traffic along your route. With the stop light icon clicked your streets will be overlaid in green, yellow and red (and solid and dashed) lines indicating how bad the traffic is. Thats a useful visual guide, but unfortunately thats the limit of the traffic interface on the Model S today — more on that later.

Destination DisplayAt the top of the display are a number of controls:

  • A button to take you to saved/special places
  • A search box to find new places
  • A button to bring your back to your current position or switch between heading up or north up modes of display
  • And a flag icon to show you your destination information.

In the settings area, under Apps/Maps, there is exactly one setting related to the map — “Map Magnification” which has a 1x or 2x option.  When you have it set to 2x it lets you zoom in twice as far as 1x – in other words at maximum zoom things are twice as big on screen.

For those that have the technology package (about 85% of owners), when navigating, a popup navigation display comes on top of the map on the left side. This can’t be hidden, but the directions that are shown are scrollable — just drag your finger up and down on the directions and you’ll see all your turns.

While related to the Navigon system below, this pop up turn guidance is also where you can control the volume or turn voice navigation off if you don’t want the helpful voice telling you about each turn to take. Unlike other systems, there are no levels that you can set for voice directions other than volume — its all or nothing with the Model S. This is also the area where you can cancel navigation.

At the bottom of the box is the remaining distance, time and estimated time of arrival (ETA) at your destination. These numbers do not take into account traffic and no information is shown relative to your destination and your range — you’re left to do that math on your own.

Voice guidance is all or nothing with the Model S.

Note that there is no option to control the display points of interest (POIs) on the map.  The only POIs they display are for super chargers and for locations you’ve used previously to charge. Tesla makes up for that with an excellent search interface which we’ll cover later but I always enjoyed being able to display POI categories on the maps in my cars in the past.

Navigon Display

Navigon DisplayWith the Model S, Navigation comes with the technology package. Without the package you get the Google maps part, but you don’t get the turn by turn directions or voice guidance. Google maps only work when your car has internet connectivity (wifi or the built in cell service) so if you go out into the wilderness you could get lost. The technology package brings in a second navigation component, a version of Navigon by Garmin licensed by Tesla, that can produce directions and maps even when there is no network connectivity.

When you have a destination entered (more on that process later), a second display becomes active automatically on your dash served by the Navigon component. This is a small section of a map that shows your route with turn by turn guidance. There’s absolutely no control over this display — there are no preferences related to this display, you can’t zoom in or out and you can’t even stop it from popping up on your dash. Once the display is up (always on the left side of your dash), you can switch away from it to another display (like Media) but next time you start navigating somewhere it will pop back up again.

This second display is pretty quirky. At times the graphics, fonts and other items can look dated or poorly done, and at other times you’ll see graphics that don’t make a lot of sense or look like they were incomplete. Then every once in a while it will surprise you with great images. Generally I use the 17″ screen more for my turn information than the dashboard one. Fortunately so far the two guidance systems have both provided identical results — it would be a real mess if they gave different recommendations.

Fortunately so far the two guidance systems have both provided identical results

One thing I really like on the Navigon display is the way they do exits. They make an exit sign that is pretty darn close to what you’ll see at the exit with a bunch information on it:


NAV ExitThey even have different pictures for day vs night. If you look closely at any of these special exit displays you’ll notice that the image is actually an overlay on top of the navigation map. Look in the top left, top right or bottom right of the display above. The images are rectangular but the map fits in the odd Tesla curved space so you get some quirky edges around these displays. Also, the image underneath is active and moving. That seems unfinished to me but its a minor nit.

One of the more quirky displays is related to telling you how many lanes are going straight versus veering off when your directions are to continue straight.


NAV LanesThe graphics and impression are underwhelming and the way this little image pops up and goes away also looks incomplete/flawed at times. If I could i’d disable it.

Display Summary

NAV MapThe maps on the 17″ screen and how you interact with them are best-of-class. They’re pulling from the immense and constantly-updated Google maps database and have a wealth of information. There’s no other car on the road with this size or quality display or a map that you can interact with in a natural way.

The maps on the 17″ screen and how you interact with them are best-of-class.

The turn-by-turn guidance map is less than what you’d get if you bought a $100 Garmin or other independent GPS system. You have less control over what it displays, the images are poor at times, and its just generally inferior to an independent guidance device.

Combined together you have a decent system that works well together for displaying map and route information. There are notable gaps in areas like POI display and control over display options (like when that dashboard guidance pops up or what it shows). The odd thing is that the Navigon engine is capable of a lot more than Tesla has enabled so perhaps we’re only a few software updates away from some improvements in this area. I do know that the turn-by-turn visual guidance in my friend’s Mazda 6, a char 1/3 the cost of my Tesla, is much more impressive.

Overall the map and guidance displays are better than what i’ve had in the past and long-gone are the days of buying a “Map Update DVD” for $250 just to get an already stale map update. Tesla’s real challenge comes in the area of navigation control and guidance which i’ll cover in the next post.

Does Tesla have better battery technology?



I bought my Model S for many reasons, but battery efficiency was not one of them. The question of whether Tesla has the best battery technology or not has been nagging at me since i’ve been learning more about Tesla and EVs in general. I set out to try to answer that question and was surprised with what I found.

Initial Comparison

I started by making a list of only 100% electric cars, what people call Battery Electric Vehicles (BEVs). I wanted to cut out the hybrids and other types as their batteries would be smaller and they would be less dependent on the quality of the battery. I ended up with 10 cars in my list. All the cars in the list use Lithium-ion batteries as they’re reportedly the highest energy and power density combined of any energy-storage medium. Each vendor uses various tricks to get their best efficiency including how they lay out the batteries, how they heat/cool them, how they set min/max charge levels, etc. 

Next I used a number of online sources to collect the basic information on battery size, EPA range, MPGe rating,  max charge rate, etc. I came up with the following table:

EV Batteries Small

 Note: the RAV4 EV had a Tesla-provided battery pack. The car and pack arrangement have ended production.

Initial analysis

One thing that immediately jumps out is that all the range per kWh results look somewhat similar. The worst is the RAV-4 but the others are all within 30% of the best — the Tesla Roadster. Second place in this efficiency measurement is the Smart Electric Drive. Some other things stand out from this data:

  • The Tesla Roadster, with its low weight and relatively large battery, is much more efficient than the Model S and was the most efficient car in this group.
  • Second place in miles/kWh is the Smart Electric Drive. Another low weight small car — Smaller, lighter cars lead the pack on miles/kWh efficiency.
  • No surprise to anyone, the Tesla’s all have the largest batteries and furthest range of any EV.
  • Also not a surprise, battery size directly correlates with range.
  • The Model S is not the most efficient car in terms of converting kWh to miles driven.
  • The Model S is also not the most efficient car in terms of MPGe ratings.
  • The larger the battery, the larger the charge rate the vendor seems (needs?) to support.
  • Tesla has the largest battery packs on the market, at least 2x any competitor.

From this data it seems perhaps Tesla has an edge in size and/or charge rate but not efficiency the way its measured here. But I suspected there was more to it than this and I wanted to dig deeper so I expanded my research to add some more data.

Perhaps Tesla has the technology edge only in size and/or charge rate

Expanded Comparison

There are some things that weren’t factored into the earlier data. Like how many people or how much cargo you’re able to move with those kWh. You can make an extremely efficient electric bike but its not very practical for moving your family around or hauling groceries. What does the data look like if you try to account for weight or cargo capacity?

EV Batteries 20140716 With this additional data we start to see different leaders. The larger batteries add a lot of extra weight of their own, but still, the Model S is more efficient at moving a pound of weight over a mile per kWh than any other EV. Other vendors aren’t too far off with the Ford Focus Electric in second place followed closely by the Mercedes B-Class.

The Model S is more efficient at moving a pound of weight over a mile per kWh than any other EV, but not by a huge margin.

Moving weight around is nice, but that needs to translate into utility. Looking at how efficiently the EVs move a cubic foot of cargo space Tesla also comes out on top. Interestingly, in every efficiency category I found the 60kWh Model S beats the 85 kWh Model S. Like weight, some competitors are not far behind like the Mercedes B-Class at 71 vs 98 for the Model S 85.

The Model S is also the most efficient at moving cubic feet of cargo capacity per kWh/mile than any other EV, again not by a large margin.


Collecting the data and reviewing it took longer than I would have liked. In raw efficiency terms the Model S doesn’t have an edge on competition. When you factor in utility you can see a bit of an edge in the Model S, but that utility alone is not likely going to justify the price difference between the Model S and the close competitors.

From the data, my main conclusion around battery technology is that for the Model S, battery size (and range) is the key differentiator by the largest factor. This may not accurately reflect the difficulty and intellectual property around building batteries that are >2x larger than the competition or supporting the necessary higher charge rates, physical layouts, etc but it is what is visible to the consumer. There also could be huge business benefits in terms of costs in choosing to go with special packaging for 7,000 Panasonic batteries vs building a specialized battery pack that we’re not able to get data for.

Personally, I bought the Model S because it is the only EV currently on the market that can handle my mileage. The EPA ranges you see above and often quoted are under pretty ideal conditions. Add some cold weather in, drive a bit faster than 55 MPH, or otherwise change those calculated factors and your actual range limit could be quite a bit lower than the numbers quoted. The discontinued RAV-4 EV was the closest competitor by a decent margin and that couldn’t do my normal day of 100 miles round trip commuting. The others are much further off.

The Model S isn’t the most efficient EV on the market, but for some people range is king. For those that don’t need the range, it’s going to come down to picking an EV that can comfortably handle their needed range and fits their style. One thing that Tesla has done very well is deliver a complete package — competitive battery technology, a nicely styled car, leading driver interfaces, etc. That all comes at a price that is difficult to justify if you’re moving to an EV to save money alone, but sometimes the total is more than the sum of the parts.

The Model S isn’t the most efficient EV, but it provides the most range and utility in the EV market.

Driving the Model S costs you more than you think



kWh UsedWhen you fill up a normal ICE car you know exactly what your costs are for the fuel. With an electric vehicle it is not that simple. There is a charging efficiency factor that comes into play which means that that energy that your car may be telling you that it used could be quite a bit lower than your actual usage.

A while back I wrote about installing an EKM Digital Submeter on my NEMA 14-50 outlet to measure actual power usage of the Model S so I could compare that to the reported power used. I had just had the meter installed and collected some initial data about the charging efficiency based on a very short interval. Now I have more data and the loss is larger than I originally expected.

Model S charging efficiency is worse than you may think.

Test Setup

I charge at home 99% of the time. So far in 3 months, 7,500+ miles i’ve only used a SuperCharger once and a HPWC (at the Tesla store) twice. At home I have a NEMA 14-50 outlet installed by a licensed electrician. I’m using the factory supplied mobile connector as the connector/cable between the outlet and the car.

Added to that outlet is an EKM digital sub meter to measure actual draw from the outlet. That meter is accurate to within 1% and does not add any measurable load of its own.


On the “anniversary date” of taking delivery of my Model S I record a bunch of pertinent information and then reset the Trip A setting. Before driving the next day I record the reading on the EKM meter. That way i’ve got the mileage and the Tesla reported power usage over the period driven and the the actual kWh used to get back to the original charge state (90% for me).

This process will let me see a bunch of information I want to track over time:

  • Monthly miles driven
  • Monthly kWh used as reported by the Model S
  • Monthly kWh used as reported by the EKM meter
  • Monthly Average energy used

I plan on using this information to look at how average energy used changes as the months/temperature changes and perhaps as the Model S gets more miles on it. Unrelated specifically to the car, but useful in other analysis is my current “all in” cost per kWh from my electric company and the current local gas price i’d be paying if I had purchased another Acura. Those will both change over time too.

While I don’t drive consistently on any given day (test drives, special trips and the like), the numbers will average out and my driving style is not likely to change much after over 30 years of driving (yeah i’m getting old but the Model S makes me feel young again!). I also drive pretty consistent patterns of commuting with a lot of miles to the same places which helps average out the special trips to locations with different terrain/conditions.

Basically, while the conditions aren’t perfectly stable over time, the averages and data from this real world testing will be pretty accurate.

The Data

The last period (6/21 – 7/21) was my first full period with both the car and the EKM meter. A month of driving and charging, especially with the miles and kWh’s involved is a decent period over which to look at the results versus the 2 days from my prior blog post.

Here’s the data:
Actual Energy June-Jul

In the above table you can see that the Model S reported 728 kWh used during the period but the meter reported 894 kWh used. This means my charging efficiency is only about 82% and electric usage (and cost) is 23% higher than I may have expected based on the readings the Model S provides. For that month this is an extra $26 of charging cost which is a small number but a decent percentage of the total. The good news is that even using this larger kWh number, the savings versus driving my old ICE car for energy alone comes in at $334 — i’m saving $334/month in gas driving my Model S!

My electric cost is 23% higher than I may have expected based on the readings the Model S provides, but i’m saving $334/month in gas driving my Model S!


External research indicates that an average charging efficiency loss in the industry is in the 10-12% range. In the forums of the other EV vendors there are people doing a similar analysis and getting charging efficiencies close to 90% (10% loss) on both the Nissan Leaf and the Chevy Volt. Consumer reports also did a study on the Nissan Leaf and reported 85% efficiency although that test was short term and possibly flawed from that.

Average charging efficiency loss in the industry is in the 10-12% range

Over this one month period of over 2,400 miles i’m seeing an 23% loss using the standard home charging setup that Tesla recommends. Many people quote an 85% charge efficiency for Tesla, and Tesla’s own charging calculator appears to assume a 91% charging efficiency which is quite different than the 82% actual charge efficiency i’ve measured and  significantly worse than the average industry charging efficiency.

It would be great to see a Model S owner do a similar test with a HPWC setup at home to see if that HPWC is somehow more efficient (it likely is) and gives results closer to what Tesla is providing. I’d love to do the test but i’m not quite ready to shell out $1,200 plus electrician costs to get that data — assuming a cost of about $3,000 all in it would take me over 20 years to break even assuming the HPWC improves my efficiency by 10%.

From the results above, my conclusion is that the Model S charging efficiency using the standard home setup is 5-10% worse than other EVs on the market.

Model S charging efficiency is 5-10% worse than other EVs on the market.

Does Tesla have better battery technology, or is this just a battle of size? More to come on that front.


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