The Nissan LEAF provides limited information via the normal information systems in the car as to what is going on with the drive train and more specifically the battery. However, there is an phone app that is available for Apple IOS and Android called “LEAFSpy Pro” that can provide you with detailed information; something that is useful for owners who want to know more about their car, and for those purchasing a used Nissan LEAF so who want to check the status of the battery before purchasing, to have the information they need to make the right decision about their purchase.
DISCLAIMER: Use of the OBDII port of your car should be done with care, you are using a device which exposes key inner workings of the car and you can potentially damage the car. The guidance provided is for information only, I won’t be held responsible for any damage or losses from following these instructions.
Hardware
The Nissan LEAF like many other cars is fitted with an OBDII port which allows you to perform diagnostics on your car. To make use of this you will need an OBDII Diagnostic Tool (Dongle).
LEAFSpy (Pro) will only work with certain types, you can find some guidance on the LEAFSpy website and also Reddit posts that discuss, I purchased this LELink dongle, which appears to work fine with LEAFSpy through my testing (at the time of writing):
LELink Bluetooth Low Energy BLE OBD-II OBD2 Car Diagnostic Tool for iPhone/iPod/iPad and Android https://amzn.eu/d/5DySs8y (£27 at time of writing)
Software
You then need a recent Apple iPhone or Android phone that has Bluetooth, you then need to download LEAFSpy Pro from your phone’s app store. There is supposed to be a free version, I used the paid for version which cost £12 (at the time of writing). Once downloaded you are then ready to start.
The LEAFSpy website provides fully rounded documentation, which I won’t repeat here, but if you need to refer to it see the links below.
https://leafspy.com/wp-content/uploads/2024/04/LeafSpy-Help-1.5.0.pdf
https://leafspy.com/wp-content/uploads/2024/04/LeafSpy-Help-1.3.10-iOS.pdf
However I’ll go on now to provide a brief overview of how to plug-in your OBDII dongle, then start the LEAFSpy app and starting collecting some data.
Brief Overview
The above LEAFSpy manuals from the website provide full documentation, but here I’ll provide the steps of how to plug-in your OBDII dongle, start the LEAFSpy app, collect some data, then some explanations of what the information means.
Connecting the OBDII Dongle
Connecting the OBDII dongle is pretty straightforward, these instructions are for a Nissan LEAF Mk2 2022 40kWh. You first ensure the LEAF is turned off, then remove the small cover underside of the steering wheel, there you’ll see a small white connector; this is the OBDII port.
Plug the OBDII dongle in, and you’ll see some lights on it start to flash, this is normal the CAN Bus is powered all of the time.
Connecting LEAFSpy to OBDII
Now open the LEAFSpy app on your phone.
You’ll be prompted to pick the connection type, here select “Bluetooth 4.x LE”, obviously make sure Bluetooth is enabled on your phone, you don’t need to pair specifically, it does this automatically from the app.
All being well you should see in the bottom left hand corner of the screen “Connected” shown in green.
Customising the Output
There are many settings to change and customise, you’ll probably want to swap things like the temperature from Fahrenheit to Celsius. You’ll need to ensure the Model Year and battery size are set correctly too to ensure your output is correct.
Examining the Output
Now we have some data being collected let’s dig into what we are being shown.
Firstly the battery screen, here we can see the GIDs, the GIDs represent the current capacity of the battery, in this case a 40kWh battery would have 500 GIDs, so mine showing 278 shows that i’ve used 222 GIDs worth of energy from the battery.
You can also see the SOC (State of Charge), this provides the current charge level of the battery as a percentage.
You can also see the temperature of the battery, in the 2022 LEAF it has three battery temperature sensors within the battery, the values given however are the maximum, average and minimum of the sensor temperatures, then the outside temperature.
So what’s next, let’s look at the battery cell information. As you can see there are a number of small lines, these represent each of the 96 cells that make up the battery pack. There’s lots of good information on here and is a good place to quickly see the health of the battery.
SOH = State of Health, this is the health of the battery, mine is showing 92.5% health, this is a 2 and a half year old LEAF, oddly the ODO (which is the odometer) is showing 11.8K miles, this is wrong, its actually done about 20k miles. If you are looking to buy a LEAF this value is the one to look at, ideally the higher the better.
The 9 QC & 947 L1/L2 shows that there has been 9 quick charges (DC) and 947 Level 2 (AC) charges.
The 13mV shows the difference in voltage between the cells, ideally this number should be as low as possible, but the cell voltages will vary as the battery is drained, it is an indicator of if you have bad cell(s) in the battery pack, the bigger the number gets between the highest and lowest voltage indicates a problem. As a rough rule of thumb 0-50mV is normal, 51-100mV is something to watch if you are going beyond that then you may have an issue with the battery. The car won’t alert you unless this value goes over 200mV of difference.
So what do the colours mean? Ideally each of the cells within the battery would have exactly the same voltage, the battery pack uses what is known as a shunt (effectively a resistor) to slightly drain the battery to reduce its voltage to balance the pack. The ones shown in Blue currently have no shunt, the ones with red are currently with a shunt applied to bring the voltage down and balance the battery.
Conclusion
So to conclude, LEAFSpy is a very power app, that can provides all sorts of useful information, more than I can cover here, but if you are looking for some simple things to assess the health of a battery of a car you are looking to buy, here are the main things to check for:
SOH = State of Health, the higher the better. Really anything over about 90% is great, anything over 85% is good, I believe the LEAF will show “1 bar loss” of battery health at about 77% SOH. A rough rule of thumb is a 2-3% SOH loss per year, so mine at 92.5% is at the top end but about right, 2.5 year old car, 2.5 x 3% = 7.5% loss.
Hx = The Hx is not well understood, but is thought to be the internal resistance of the battery, here higher the better, if this value is low, it indicates that the resistance within the battery is lower which means greater heat during heavy use or charging.
Battery Voltage Difference = The value (in my case showing 13mV) gives you a an idea of the voltage different between the cells, lower the better. If this is a large number it indicates you may have bad cell(s) within the battery, you should also see the bad cells listed if this were to be the case.
QCs = It is known that with the LEAF battery pack that rapid (quick) charging reduces the lifetime of the battery, therefore a large number of Quick Charges would indicate that the battery may have aged more quickly that one that has not had any/many Quick Charges, depending on the age of the vehicle and how it was used would affect this.
Hopefully that brief overview has been of use, there is so much to see in the app, the manual is a great place to start.
