Record of Electrical Use While Charging

[RYoungberg]

FYI - I have a Leaf 2019 62 kWh battery, I use the charging cable that came with the car plugged into an outlet specifically installed for charging the LEAF.
Question:
Is there software or a device to record the actual amount of electricity used for each charge? Date, time of day, kWh. I'm trying to separate the electricity used to charge the car from my household electric use for tax purposes and time of day electricity charges.

Also would like to keep a record of when my solar system is charging the LEAF vs pulling electricity off the grid.

Separate question - Does the rate of amps used to charge vary with how full the battery is? For many batteries charging is faster when at low capacity, slower when almost full. Not sure if this applies to the Leaf battery.

Thanks!

 

[henrydehoja]

For electricity usage with solar panel systems, you may want to check out the Sense Home Energy Monitor. It can monitor specific circuits and solar power usage. I have no experience with it, but have looked into a bit.

And, yes, the Leaf's on-board charging system will vary the rate of current (amps) drawn from the EVSE based on the battery's state of charge level.

 

[Flyct]

FYI - I have a Leaf 2019 62 kWh battery, I use the charging cable that came with the car plugged into an outlet specifically installed for charging the LEAF.
Question:
Is there software or a device to record the actual amount of electricity used for each charge? Date, time of day, kWh. I'm trying to separate the electricity used to charge the car from my household electric use for tax purposes and time of day electricity charges.

Also would like to keep a record of when my solar system is charging the LEAF vs pulling electricity off the grid.

Separate question - Does the rate of amps used to charge vary with how full the battery is? For many batteries charging is faster when at low capacity, slower when almost full. Not sure if this applies to the Leaf battery.

Thanks!

Another member installed an additional electric meter on his 50 amp receptacle. It’s was relatively inexpensive. See here https://www.mynissanleaf.com/viewtopic.php?f=10&t=28063&p=609718&hilit=Meter#p609718

 

[Flyct]

FYI - I have a Leaf 2019 62 kWh battery, I use the charging cable that came with the car plugged into an outlet specifically installed for charging the LEAF.
Question:
Is there software or a device to record the actual amount of electricity used for each charge? Date, time of day, kWh. I'm trying to separate the electricity used to charge the car from my household electric use for tax purposes and time of day electricity charges.

Also would like to keep a record of when my solar system is charging the LEAF vs pulling electricity off the grid.

Separate question - Does the rate of amps used to charge vary with how full the battery is? For many batteries charging is faster when at low capacity, slower when almost full. Not sure if this applies to the Leaf battery.

Thanks!

Another member installed an additional electric meter on his 50 amp receptacle. It’s was relatively inexpensive. See here https://www.mynissanleaf.com/viewtopic.php?f=10&t=28063&p=609718&hilit=Meter#p609718

Here is a link to his list of parts. https://www.mynissanleaf.com/viewtopic.php?f=10&t=28063&p=609733&hilit=Meter#p609733

 

[pdbscw]

... nice details to know...lot o' work... Yes, they charge faster on 'empty' battery.. middle third charging is leaps and bounds faster than that last 25%. I think someone did that theoretical calc that showed you could charge to 75% twice and get somewhere faster than the with 99% wait times. Separate power meter would show/record that stuff at a source to car. Amp meter equipment is lots cheaper than before. IDK
I would expect mileage at (....is it still .54/mile for business mileage write off?) to be greater tax deduct..,. but you may have some better idea.
'99 Emerald Phx Az

 

[GerryAZ]

I installed a digital revenue accuracy meter ahead of my 14-50 receptacle to record charging power at home and another at my workshop. EKM Metering has several different meters that will work, depending upon how much information you wish to track. I have a feed-through basic meter set up for portable 240/208-VAC use and Omni Meters associated with my 14-50 receptacles at my house and my workshop.

Here is a link to their site: https://www.ekmmetering.com/

 

[johnlocke]

Emporia Energy makes a whole house monitor that can monitor up to 16 separate circuits individually. Ammeters clip over the power lines to monitor current. I use their utility monitor to check my solar PV output. That ought to fit your need.

 

[SageBrush]

If you have a JuiceBox or Grizzl-e EVSE monitoring comes with the package.
As mentioned above meters are cheap but if you have to pay for installation it is another $200 - $400.

The modern and cheap way is to buy a ~ $20 CT (current transformer) to measure current, attached by a wire to an electronic gadget that monitors consumption and relays it to your phone over wi-fi. The device sits somewhere convenient in your electric panel and pulls a small amount of juice from the panel. I am not sure whether a breaker is required but I doubt it (or at least presume alternatives are available.)

---
If your project is purely money and no curiosity, be aware that it is pretty easy to spend too much money since the tax savings are not a lot of money. E.g.,

Let's say 3000 kWh a year consumption for 12k miles
If a kWh is 12¢ then EV fuel is 3000*0.12 = $360 a year
If you are in the 12% marginal tax bracket then your annual savings is 360*0.12 = $43.2** That savings is eaten alive if a CPA prepares your
taxes

Unsolicited advice for fuel cost calculation (not whether it is worthwhile):
Keep a log of your tax deductible eligible miles. The IRS will expect this in an audit
Once a year reset your miles/kWh meter
Once a year multiply your eligible miles * kWh/miles * cost_per_kWh. That is your fuel cost deduction

**Do you itemize deductions ? If not, I suspect that this entire exercise doe not apply to you unless you get mileage compensation from work.

 

[rlmalisz]

Not the cheapest way to go, but we got a Wallbox, which tracks the juice used. As a bonus, it has a interface that you can work with over the network (or locally via Bluetooth) to start/stop charges...their phone app uses basically the same interface.

Some clever person wrote a Python library for talking to the box (via Wallbox's servers) that can fetch all sorts of current session values, pause the session. So I wrapped that in a Python script, which gets invoked by an in-home, private network PHP page. Set up an Apple shortcut to hit that. I get home, plug the LEAF into the Wallbox, bring up the shortcuton the watch. It queries me for starting charge percent, ending charge percent, asks for confirmation, and away it goes. I get notices of progress for every even 10%, notified when the goal gets hit, and the script pauses the charge there. Allows me to plug in, tell it what to do, and unplug whenever after it's done.

Python library is here: https://pypi.org/project/wallbox/#files

--Richard

 

[watchdoc]

Not the cheapest way to go, but we got a Wallbox, which tracks the juice used. As a bonus, it has a interface that you can work with over the network (or locally via Bluetooth) to start/stop charges...their phone app uses basically the same interface.

Some clever person wrote a Python library for talking to the box (via Wallbox's servers) that can fetch all sorts of current session values, pause the session. So I wrapped that in a Python script, which gets invoked by an in-home, private network PHP page. Set up an Apple shortcut to hit that. I get home, plug the LEAF into the Wallbox, bring up the shortcuton the watch. It queries me for starting charge percent, ending charge percent, asks for confirmation, and away it goes. I get notices of progress for every even 10%, notified when the goal gets hit, and the script pauses the charge there. Allows me to plug in, tell it what to do, and unplug whenever after it's done.

Python library is here: https://pypi.org/project/wallbox/#files

--Richard

Does your Wallbox support V2G yet?

 

[OldManCan]

Do you use the Nissan Connect EV app? It does provide a report called "Electricity Rate Simulation" which might give you some of the insights you're looking for. Also the Electricity Usage report tells you what you have consumed as you drove around but since you can only consume what you put in through your charger this also would give you some visibility. Hope this helps.

 

[fester]

If trickle charging using 120vac, you can use a variety of in-line wattmeter (KiloWatt, etc.) For 240 volt monitoring (whole house), I've use a Brultech GEM with current transformers on all the breakers. Plus a Brultech Dashbox to constantly record data from the GEM Monitor. The Dashbox takes the place of having to run software on a computer 24/7 and hosts its own Web Page on your Browser to give you current use on every circuit or it can store and display long term records of your use. I used this setup for several years now with good results ( a bit expensive though, but worth it to me to keep track). just my 2 cents...

 

[goldbrick]

I wish I could rent one of those for a few weeks. It would be interesting data.

 

[salyavin]

Not sure if this would help you https://driveelectriccolorado.org/rolling-energy-resources
their signup page covers many states.

 

[RAZ_ELLEN]

FYI - I have a Leaf 2019 62 kWh battery, I use the charging cable that came with the car plugged into an outlet specifically installed for charging the LEAF.
Question:
Is there software or a device to record the actual amount of electricity used for each charge? Date, time of day, kWh. I'm trying to separate the electricity used to charge the car from my household electric use for tax purposes and time of day electricity charges.

Also would like to keep a record of when my solar system is charging the LEAF vs pulling electricity off the grid.

Separate question - Does the rate of amps used to charge vary with how full the battery is? For many batteries charging is faster when at low capacity, slower when almost full. Not sure if this applies to the Leaf battery.

Thanks!

Tesla does this out of the box. It’s built into the Tesla App. And I use it for exactly the same reasons as you. It isn’t “a lot of work” as someone said in this thread. 2mins every morning. I set up an Excel spreadsheet and use the Excel Card function to make it easy to enter the data via my phone but it’s pretty easy even as a native Excel Spreadsheet.

The charge stats from the Tesla apps plus a bit of other data from my Fronius Inverter enables me to know exactly what the house is using and what each of the two Tesla’s are using. I use the data to calculate when my investment in my various Residential Renewable Energy technologies will break even. Teslas will break even i.e. petrol & maintenance savings will have offset the extra cost of the Tesla’s in about 5-6 years from the date of purchase.

I’m about to install a little Open Source system called Home Assistant ($200AUD for the pre-installed hardware. Software is free). This is so that I can get the same data for my daughter’s Leaf that she bought 2 days ago. I’m hoping the LEAF has WiFi. Home Assistant has loads of functionality including tracking power used by each WiFi connected device in the house. In the meantime I’m using the Leaf’s battery % before and after charging to calculate an estimate of the KW’s used on each charge.

HOME ASSISTANT INFO:

Hope that helps.

 

[fester]

Actually if you're using the OEM trickle charger (which is all I need), and need to monitor a 120v outlet; invest 20-30 bucks in a Kilawatt Meter. Its a plug and play, just plugs into the outlet, then the OEM adapter plugs into it. It would give you watts, amps, totals, etc. That's your cheapest and easiest solution.
As I said in the earlier thread I use a Brultech GEM and DashBox to monitor all my household circuits. As to whether the power to the Leaf Charger remains constant, it does until near 100% charge. It will hold around 1450 watts until 99-100%, then start to ramp down to around 600 watts, then go to nearly zero for about 5 minutes. After 5 minutes at 0, it will begin a lower charge rate which then ramps off to zero. It repeats this 3 times, then charge is 100% and complete. I allow it charge to 100% perhaps once a month, then driven shortly thereafter drive and keep the battery 50-80%, which works well for my needs.

 

[zowland]

I used an Onset HOBO data logger to monitor my Leaf and Tesla charging currents for many years.

https://teslamotorsclub.com/tmc/threads/measuring-the-total-energy-consumption-of-your-ev.12706/