Published Saturday December 26, 2015

Review of the Leaf Spy App

I love that electric cars display things like state of charge and miles remaining. But the inner nerd in me wishes to have even more parameters and information about how my car is operating.

The Leaf Spy Pro app and an OBDII to WiFi adapter fill that need.

I can now read the battery pack voltage, current draw, the voltage of each individual battery cell, power going into the motor or regenerating back into the battery pack as well as dozens of other parameters.

It can even measure how much capacity loss the battery pack has incurred verses a brand new battery pack. This is displayed in either kilo-watt-hours or in GIDs, (a weird parameter where when fully charged, 281 is a perfect pack and anything less is a battery pack that has some capacity loss).

 Leaf Miles SOC GIDs kWh
 Raj (2012) 14,416 92.7% 250 19.4
 Edith (2013 18,886 97.1% 271 21.0

My favorite feature is the watt-hour meter. It incrementally displays the energy used while driving. With it, you can measure exactly how much energy it takes to drive a particular route, make improvements in driving style, tire air pressure, then repeat the same route and be able to receive feedback on what improves energy economy or what hurts it.

Here is some data over the last 6 months from my commute driving to work, 19.5 miles on the freeway and some city roads.

 Date kWh Notes
 6/25/2015 3.145Warm outside but no AC. Best commute ever.
 8/5/2015 3.900 High headwind
 8/6/2015 3.663 57 mph on Legacy, and 67 mph on I-215
 8/11/2015 3.828 57 mph on Legacy, and 67 mph on I-215
 8/12/2015 3.210 Bit of congestion and traffic on the way in
 8/13/2015 3.163 57 mph/67 mph. Bit of a tailwind. 
 8/14/2015 3.323 Traffic backed up on Legacy
 10/30/2015 5.707 slight tailwind, cab heat blasting, 38°F outside
 11/13/2015 5.840 cold 27°, heater cranked to 80°
 12/23/2015 4.954 cold, slushy and windy. Heater on

Notice how much energy economy drops during the winter time! I attribute this to higher air density caused by colder air temperatures and heater usage.

After driving a particular route, it’s really fun to check the data and see how much energy was recovered through regenerative braking.

Here is a screenshot from my friend Jake Russel’s Leaf, after he drove down the canyon from Snowbird ski resort.

He regenerated a lot of energy going down that canyon. How awesome it is to be able to recover and use that energy instead of having to throw it away as heat in the brakes.

The Leaf Spy app also keeps track of odometer mileage and the number of times you have charged the battery, (both from regular L1/L2 and L3 rapid charging). 

My 2012 Leaf (Raj) has been driven 18,577 miles, been quick-charged 11 times and has been charged 834 times using the on-board charger. 

It also shows battery temperature (not shown here) and tire pressure of all 4 tires as well as delta pressure between tires.
It’s neat to see how the pressure increases from the beginning of the commute to the end.

Warning: Do not interact with this app while you are driving. Until self-driving cars come along, I prefer to start the app on my phone and then set the phone down so I can focus on driving to work. Once I get to work and park the car, I can quickly review the data collected on the app or take a screenshot of the app and review the data later.

The i-phone version of the app requires an OBDII to WiFi adapter and the android one uses OBDII to Bluetooth. I wish both adapters used Bluetooth because having the app connected to a WiFi access point with no internet access is a pain when you are also trying to do stuff through other apps on the phone. Sometimes the Leaf Spy app will jump onto another WiFi hotspot which stops the date about the car from being collected.

The OBDII adapter I have draws probably 1-2 watts all the time, even when the car is off and the wifi is not active. That bugs me that it drains energy from the cars battery, even when it doesn’t have to, all while not serving any useful purpose.
To this end, I opened up my OBDII adapter and soldered in a power switch.

Added a switch to the front. 

Cut pin 16 on the OBDII connector and wire a switch inline. 

Switch wired up to in line with pin 16 on the OBDII plug. 

Modified OBDII to WiFi adapter with power switch.

Now the adapter can be turned off when I’m not using it. 

I also put in an OBDII extension cable so I can keep the adapter in a more handy location.
Overall, I love the Leaf Spy App.  It is available on Android or i-Phone for $14.95
The WiFi or Bluetooth to OBDII adapter can be purchased here.