Temperature and Battery Charging

 

Battery Temp and Charging Rate

If you’re new to electric cars you may have heard terms like ‘cold gate’ or ‘rapid gate’.  What do they mean?  Both terms reference how battery systems operate for charging.  Li-Ion batteries operate best in a narrow temperature window, which closely matches temperatures that are comfortable for people.  When hot or cold, these batteries can perform poorly. When charging the vehicle, systems are designed to limit the charging current to protect the battery and help ensure a long life for the batteries.  The restrictions impact DC fast charging the most as this is when the most current is trying to go into the battery pack.

Cold Gate refers to when the vehicle battery pack is below optimum operating temperature.  Specific to my Kia Niro, if the battery pack is below 77 degrees Fahrenheit the vehicle will limit the charging power allowed.  There are several different charging curves based on the state of charge and the temperature.  The other day I went to evaluate the 10% to 80% charging speed, a very typical range for a road trip.  The target is to arrive at a charger around 10% and charge at the highest rates to be the most time efficient.

 

The time to charge in this session was 50 minutes from 11% to 80%.  Not bad, but here is a chart that shows the speed at which Elektra was charging at each point.

 

The chart shows that it started charging at 54kW and charged at this lower rate for 13 minutes before jumping up into the 74 and then 77kW peak rates of charge.  As the pack fills, the rate also slows.  In this case, at 60% the rate drops from the upper 70’s to about 60kW, and then at 75%, the rate drops to 38kW, and again at 80%, the rate drops to 26kW.

I would love to do a full side by side comparison with the new Mach-E.  It has a bigger battery pack, but higher peak and sustained charging speeds.  However, above 80% the Mach-E only charges at 12kW.  On a long distance trip, I think both cars would do about the same amount of time, especially if there are long stretches that require charging the batteries to higher than 80%.

In the above example, I could see that Elektra actually ran a heater to help warm the battery to reach peak charging speeds.  I am still working out at what percentages and what temperatures the battery pack heater will run.

Since battery temperature is so important to charging speed, I would recommend that car companies add a battery temperature gauge to the meter display.  Many new electric drivers may not take the time to learn about this impact and not understand why the car is not charging as fast as possible.  A simple gauge showing the battery temperature below or above preferred operating range would inform the user why the battery is not charging quickly.  Also, more companies need to implement the battery conditioning features from Tesla.  If you select a supercharger station as the destination in the Tesla navigation, the car will start to condition the battery (actively heat or cool) so that it is at the optimum temperature for charging at arrival.  In the meantime, I may look for a hack on the Kia to run the battery heater more so I can achieve more charging time at the fastest speeds.

For me, the battery being cold is my main concern, but most car battery packs are also thermally cooled, so when they get hot the system can run to cool the battery as well.  Unfortunately, that is not the case for the Nissan Leaf.  That battery is only heated and cooled by the air around it. 

This brings me to Rapid Gate.  The process of DC Fast Charging introduces heat into the battery pack.  Most people would be familiar with batteries getting warm while charging.  In the case of the Leaf charging and driving create heat, and in warm conditions the battery pack will warm to the point that the vehicle charging system will slow the charge rate to protect the batteries.  Thus, the Nissan Leaf which starts with slow charge rates can be limited to even slower rates once the battery is hot.

 

Meijer - West Ann Arbor, MI

 

Introduction

Welcome to my Charging Site reviews.  One of the reasons I decided to start a blog was to share information about Electric Car Charging locations.

Business/Location Name	Meijer
Address	5645 Jackson Rd. Ann Arbor, MI 48103
Network	Greenlots
Station Details	2 - 50kW Stations, 4 - Level 2 Stations
Cost	$0.30 per kWh

This was the final stop on our recent I-94 corridor charging site investigation trip.  This site is on the west side of Ann Arbor, MI and can be found at exit 169, Zeeb Rd. The chargers are at the local Meijer store, relatively close to the highway.  This stop and many of the newer Meijer locations is managed by the Greenlots EV charging network.  Greenlots is directly affiliated with the Shell Oil Company, showing how the gas companies are trying to keep up with the switch to electric.

Accessibility

The chargers here were not at the Meijer gas station as we first thought.  They’re ocated on the far right hand side of the parking lot as you are facing the Meijer.  The site is only 0.5 miles from the highway.  The straight in parking works well for Elektra, but means that vehicles with rear charging points, like the BMW i3 in the photo, need to back into the charger parking spots.  This arrangement also blocks the ability to charge while pulling a trailer.   It is nice that the chargers are near the front of the store, but being at the far edge of the parking lot means that these spots will surely remain open for those in need of a charge.

 

Amenities

Meijer is one of those one stop stores with a little of everything you need.  The Meijer gas station is very close with the basics.  The all-important food options: Arby’s, Taco Bell, Panda Express, Wendy’s, Starbucks and Burger King.  Nearby shopping includes an AutoZone, and a CVS.  There is no covering for the chargers, so they could easily become icy or blocked by snow in the wintertime. 

 

Concentration

The 2 DC Fast Chargers and 4 Level 2 outlets are plenty for this site.  Those travelling and using this site will likely not face any problems with finding an available charger at this site.  I would like to see more chargers along the I-94 corridor, but this is more of a shopping stop than a road trip stop.

 

Location

This is an excellent multipurpose site.  The closeness to the highway makes for a good road trip stop, and being a large shopping center makes for a convenient charging stop while shopping (especially on the Level 2 chargers that are free for the first hour).  Being on the western edge of Ann Arbor travel into or out of the Ann Arbor/Detroit area is well supported by this site.

 

Speed

These Tritium DC fast charging units can do up to 50kW charging.  This is good for the existing Bolt EV and other older EVs that have smaller battery packs and slower charge rates.  Newer EVs all have faster charging and larger batteries.  As an example with the new Mach-E charging at 100kW for some other stations, if that vehicle were to charge here, it would take twice as long.

 

Summary

What would a charging adventure be without issues at least one stop?  We pulled up to the chargers, and I parked in front of the right hand side charger.  Plugging in, I opened the Greenlots app to start the charging session.  After selecting the charger, I was confronted with a spinning circle showing authorizing, and then eventually it timed out and the charging never started.  So, I moved over to the next charger, and tried again.  Unfortunately, the same error presented itself on this charger as well.  I called the charge network provider and in less than one minute, I was speaking with a helpful gentleman from Greenlots.  He was able to get our charger reset and initialized our charging session.  While I was on the phone with him, an BMW i3 driver arrived and plugged in.  We informed him we were on the phone with Greenlots and also requested to reset the other charger for him.  In a short time period, we had both vehicles successfully charging.

With Elektra charging, we headed inside the Meijer for a restroom break and electronics section investigation.  This Meijer had no music for sale, we could not find Vinyl, Tape, or even a single CD for sale.

 

 

What I paid for this stop:

Total Cost: $3.87

Total kWh: 12.89

Time: 17 minutes

Average Charge Speed: 45.49 kW (Calculated)

Cost per kWh: $0.30

 

Total Score (Max 44)	Score Percentage	Accessibility Total	Amenities Total	Concentration	Location	Speed
24	54.5	4	8	6	4	2

 

Trip summary:

Total Paid: $14.46

Total kWh: 52.18

Total Miles: 244

 

Jackson County Airport

 

Introduction

Welcome to my Charging Site reviews.  One of the reasons I decided to start a blog was to share information about Electric Car Charging locations.

 

Business/Location Name	Jackson County Airport
Address	3606 Wildwood Ave Jackson, MI 49202
Network	Red E Charge
Station Details	3 - 50kW Stations, 2 - Level 2 Stations
Cost	$0.35 per kWh

I decided to investigate another I-94 corridor charging site in Jackson, MI.  The site can be found off the Airport Rd exit. The chargers are at the Jackson County Airport, a bit of a distance from the highway at this exit.  This stop is the first site I’ve visited that is not a ChargePoint network site. 

Instead, this site is operated by a company called Red E Charge.  They claim on their website to be “Michigan’s largest public EV charging network”.  Red E Charge doesn’t have their own application for a smartphone like most other charging networks.  Each charger has a QR code that links you to their website to start charging and pay for your charge.  Speaking of payment, at this site the rate is $0.35 per kWh.  Unlike ChargePoint, which typically has been charging by time, many networks will charge you for energy you actually use.

 

 

Accessibility

This station is on the southeast edge of the airport parking lot and is not readily visible since it’s about 2 miles off the highway.  The parking spots are diagonal, making the reach of the already short cables likely to be more of a stretch to vehicles with plugs on the sides.  This was no problem for Elektra with her front charging port.  The airport has a nice sized parking lot, so it’ unlikely that a car that was not charging would be parked in these spots.

 

Amenities

There’s not much to speak of in the way of amenities at this stop.  Stopping here would likely be for a restroom break or to charge your car.  There are no overhead coverings for the chargers, so they could easily become icy or blocked by snow in the winter-time.  There are a couple of options for stops from the highway exit to the chargers, but once you’re at the chargers, nothing in a walkable range.  Also, there are no standard automotive amenities at this stop.  No washing windows, airing up tires, or accessible trash cans to be had here.

 

Concentration

The 3 DC Fast Chargers and 2 Level 2 outlets are sufficient for this site.  Those traveling and using this site will likely not face any problems with finding an available charger if choosing this site.

>Level 2 Charger - A couple of Enel X networked chargers<

 

Location

I don’t think this is a great location for a charging site.  It’s a bit off the highway, and not even noticeable from the main road.  This site may help some travelers on the I-94 corridor, but I don’t see it being a heavily used location.  I may be wrong, and this location may end up being very popular.  I will hope so, since diversity in the charging networks will help to maintain competitive pricing and service.

>No noticeable road facing signage.  You wouldn’t know this was here if you were not looking for a charging stop<

 

Speed

These Tritium DC fast charging units can do up to 50kW charging.  This is good for the existing Bolt EV and other older EVs that have smaller battery packs and slower charge rates.  Newer EVs all have faster charging and larger batteries.  As an example, with the new Mach-E charging at 100kW for some other stations, if that vehicle were to charge here, it would take twice as long.

Summary

I will likely not be using this stop again unless there were a critical need to charge while traveling this part of the I-94 corridor.  The distance from the highway, the lack of amenities and the lower speeds make this a less than desirable stop.  

Since this is my first time charging with a Tritium charger, I was surprised by how loud the high pitched hum was that these chargers make.  We could hear the charger from halfway across the parking lot.  I definitely wouldn’t want to sit and listen to that noise the whole time I am charging.  Fortunately, on this day the weather was nice and we could get out and explore the area allowing us to get away from the noise of the chargers.

 

What I paid for this stop:

Total Cost: $2.55

Total kWh: 7.28

Time: 9 minutes

Average Charge Speed: 48.53 kW (Calculated)

Cost per kWh: $0.35

 

Total Score (Max 44)	Score Percentage	Accessibility Total	Amenities Total	Concentration	Location	Speed
15	34.1	3	0	6	4	2

 

Johnny's Markets - Marshall, MI

 

Introduction

For today’s review, there will be a 2 for 1 review.  I’ll be sharing information on two sites within 10 miles of each other.  Both have similar layouts and features.  Also, these sites show that the electric charging infrastructure is being built up quickly.  The first site has only been open a couple of months, and the second site is less than two years old.  (Google Street view images from 2019 show the chargers were not there)  Up first is:

 

Business/Location Name	Johnny's Markets
Address	104 Winston Dr Marshall, MI
Network	ChargePoint
Station Details	2 linked 62.5kW Stations or 125 from one station
Cost	$0.20/min

 

This Johnny’s Markets stop is at exit 36 of I-69, in Marshall, MI.  This site serves the northeast to southwest corridor from Port Huron, MI to Coldwater, MI.  This site is only 70 miles away from the site of my previous PS Food Mart review.  The basic layout here matches the standard layout with a couple of chargers at a gas station with a convenience store.  This time, we are at a Shell gas station just off the highway.  In fact, you can see the entrance ramp sign in the site picture below.

 

Accessibility

This station is in the northwest corner of the gas station parking lot.  Taking Michigan Ave (Business 69) east from the freeway exits, the gas station for this stop is located on the southeast corner of the highway intersection.  These chargers are placed off to the right of the gas pump, and thus very unlikely that a car that was not charging would park in these spaces.  However, since the parking is nose- in, there’s no pull through parking for anyone pulling a trailer.  We could tell this site was almost brand new as the concrete had not been backfilled for landscaping as of yet.   Nice for a site like this was some tree cover, beneficial in the summer time for blocking some sun.

 

Amenities

This stop offers much of your standard gas station stop fare.  Window washing, air for tires and trash cans are all within the same parking lot.  Right at the gas station is a Subway sandwich shop.  Other walkable fast food options include: Taco Bell, and Wendy’s.  There’s no covering for the chargers, so they could easily become icy or blocked by snow in the winter-time.  The direction of the chargers will make completely clearing snow from the front of the chargers difficult in winter-time.  If you’re in the mood to do some shopping, be sure to check out what must be one of the few remaining open K-Mart stores just north of the chargers across Michigan Ave.  This K-Mart is a shell of what it once was, but still remains mostly a one-stop shop.  They have a pharmacy, refrigerators, groceries, clothes, luggage and various other items in stock.  There was no electronics section, and the Little Caesars pizza shop inside the store was closed.

 

Concentration

Even for a secondary site like this, two chargers aren’t enough for this site.  On a secondary route like I-69, there should be more chargers available.  This site has room to grow but it will take more to add to this site and currently, site is not well used at all.  If the ChargePoint app is to be believed, I was the last person to use charger #1 at this site 2 weeks ago.  It seems like it charges about one car per day.  For sites like this to make money, they will need to get significantly more traffic.

 

Location

Overall, I think this is a pretty good location for a charging stop.  At about 70 miles from the other charging stop along I-69, this site would serve any electric drivers that are traveling this highway.  This stop supports more highway miles to be comfortably travelled without concern about charging options.

 

Speed

These ChargePoint shared power chargers are a decent solution for now but will quickly become taxed by the next round of electric vehicles.  With more vehicles like the ID.4 and Mach-E coming that can do 100kW+ charging by themselves, combined 125kW stations like this will be strained by just one of these cars, and if two try to charge at the same time, it will result in much slower speeds than possible.  Thus I score this stop as just adequate. 

 

Summary

We enjoyed the quick stop here and the chance to visit a K-Mart was something we don’t get to do every day. 

 

What I paid for this stop:

Total Cost: $1.79

Total kWh: 8.23

Time: 9 minutes

Average Charge Speed: 54.87 kW (Calculated)

Cost per kWh: $0.217 (Calculated)

 

Total Score (Max 44)	Score Percentage	Accessibility Total	Amenities Total	Concentration	Location	Speed
24	54.5	5	7	6	3	3

 

The second stop

Wait, haven’t I been here before?  Yes, this site was the last stop on my “bringing Elektra home adventure”.  If you haven’t read that blog post yet, it’s definitely worth the read.

Business/Location Name	Johnny's Markets
Address	15423 US-27 Marshall, MI
Network	ChargePoint
Station Details	2 linked 62.5kW Stations or 125 from one station
Cost	$0.20/min

This Johnny’s Markets stop is at exit 110 of I-94, in Marshall, MI.  This site serves the east to west corridor from Detroit, MI to Chicago, IL.  This site is about 100 miles away from Detroit and 160 miles from Port Huron, MI the eastern terminus of I-94.  The basic layout here matches the standard layout with a couple of chargers at a gas station with a convenience store.  They’re located at a Shell gas station just off the highway.  In fact, at night you can see the lights on the top of the chargers from the eastbound exit ramp as noted in my previous story.

 

 

Accessibility

This site is on the west side of the gas station parking lot.  You can find the Shell gas station just North of I-94.  These chargers are placed behind the gas station convenience store, and thus very unlikely that a car that was not charging would park in these spaces.  The spacing here could allow for a vehicle with a trailer to pull alongside the chargers, but that would likely block the second charger.  This is a great site for ease of use for a quick on/off the highway charge.

 

Amenities

This stop offers much of your standard gas station stop fare.  Window washing, air for tires and trash cans are all within the same parking lot.  Right at the gas station is a Subway sandwich shop.  The only other food option here is the Free Range Pancake House.  There is no covering for the chargers, so they could easily become icy or blocked by snow in the winter time, but the positioning does allow for ease of snow removal.  If you are in the mood to do some shopping, you are out of luck at this stop - there isn’t anything around.

 

Concentration

On a primary route, at a site like this, two chargers is not enough.  This site has room to grow but it will take more to add to this site.  I am excited to see Johnny’s Market being an early supporter of electric cars.  As the electric car population grows, I hope that the usage of a site like this will support expansion. 

I also hope the electric utilities continue to offer incentives to build up sites like this one.  (https://www.consumersenergy.com/residential/programs-and-services/electric-vehicles/dc-fast-charger-rebates)

 

Location

Overall, I think this is a pretty good location for a charging stop. Right along the I-94 corridor, this site would serve any electric drivers that are traveling this highway.  This stop supports more highway miles to be comfortably travelled without concern about charging options.  The location decision is also supported by the fact that just across the highway at the Citgo gas station is a Tesla SuperCharger station.  A group could travel with a Tesla and non-Tesla and stop to charge at basically the same location.

 

Speed

These ChargePoint shared power chargers are a decent solution for now, but will quickly become taxed by the next round of electric vehicles.  With more vehicles like the ID.4 and Mach-E coming that can do 100kW+ charging by themselves, combined 125kW stations like this will be strained by just one of these cars, and if two try to charge at the same time, it will result in much slower speeds.  Thus I score this stop as just adequate. 

 

Summary

This has been a very reliable stop location for me.  While in the winter time, Elektra was clearly coldgated, and we saw good speeds from the charger for the temperature and state of charge of the battery at this stop.  Combining the 2 locations within 4 miles of each other offering 4 chargers is a good number of chargers for a relatively small area.  I will likely use these stops on future road trips.

 

What I paid for this stop:

Total Cost: $1.05

Total kWh: 5.02

Time: 5 minutes

Average Charge Speed: 60.24 kW (Calculated)

Cost per kWh: $0.209 (Calculated)

Total Score (Max 44)	Score Percentage	Accessibility Total	Amenities Total	Concentration	Location	Speed
24	54.5	6	5	6	4	3