like2bike
Posts: 65
Joined: Tue Oct 18, 2016 2:13 am
Location: Long Island, NY
Contact: Website

Re: Cost of charging?

Tue Oct 09, 2018 1:02 am

I think the difference between L1 and L2 is much more the than most people would guess. I am working on doing a comparison study but don't have very accurate numbers yet. One thing I noticed was that the Bolt L1 cable uses 16 gauge wire while my 2013 LEAFs L1 used 12 gauge. I calculated the Chevy L1 would use 15 watts more in cable loss at 12 amp charging. My present estimate for the charging efficency is as follows:

Measured from breaker box to DC into battery on the Bolt, 12A Chevy L1, 7.2KW L2:
L2: 94%
L1: 88%

Admittedly, one big factor is the L2 was installed next to the breaker box to minimize wiring loss and the L1 is coming from an existing 15A outlet on the far end of my garage. I did change the outlet receptacle to a commercial grade one though.

Hopefully, I'll have more accurate data soon.
2019 Chevy Bolt LT w/ FC & DC II, named Orion L-ion
2013 Nissan LEAF S w/ QC, named Leafy McLeaf Face
2014 Toyota Prius v/5
Schneider EVlink L2 charging
EV driver since March 2013

GetOffYourGas
Posts: 1092
Joined: Tue Oct 20, 2015 5:25 pm
Location: Syracuse, NY

Re: Cost of charging?

Tue Oct 09, 2018 11:30 am

Taking your numbers at face value:

To charge at L2, you need roughly 60/.94 = 63.8 kWh
To charge at L2, you need roughly 60/.88 = 68.2 kWh

The difference is 4.4kWh, or $0.53 at $0.12/kWh.

Even charging fully twice a week (that's a lot of driving!), it's $1.06/wk or $55.12/year. It would still take 9 years to break even with SparkE's $500 L2 EVSE. And that number is low if you need to call an electrician.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV (traded for Bolt)
2015 C-Max Energi (302A package)
2017 Bolt Premier

User avatar
Arob216
Posts: 16
Joined: Tue Apr 10, 2018 6:46 pm
Location: Colorado

Re: Cost of charging?

Tue Oct 23, 2018 5:48 pm

Power companies transmit at very high voltage to overcome resistance\loss en-route. As a % of power delivered, resistance consumes a bit less power.

Also, with a shorter charge time, if battery conditioning kicks in due to extreme temperatures, the shorter charge time translates to less conditioning time. So in extreme hot or cold, the efficiency of L2 improves even more than in 60-80F temps.

https://www.veic.org/documents/default- ... ciency.pdf
2018 Chevy Bolt Premiere, Nightfall Gray

like2bike
Posts: 65
Joined: Tue Oct 18, 2016 2:13 am
Location: Long Island, NY
Contact: Website

Re: Cost of charging?

Fri Oct 26, 2018 3:15 am

I have more confidence in my measurements now and I still have similar results. I will also show results without the house wiring loss:

Breaker Box to DC into battery: 87.8% for Bolt L1, 94.1% for Schneider L2.
Wall plug to DC into battery: 89.6% for L1, 95.3% for L2 (actually hard wired).

For me the cost difference for a full charge would be $1.01
$0.22 x (60/87.8 - 60/94.1) = $1.01

Surely not a great payback. But here are the other advantages of L2:
    Safer, no 120V outlet used.
    Faster charging (this is more often an advantage with the LEAF)
    Money going to EV infrastructure instead of electric.

When you realize you're not going back to ICE, it's time to take the plunge.
2019 Chevy Bolt LT w/ FC & DC II, named Orion L-ion
2013 Nissan LEAF S w/ QC, named Leafy McLeaf Face
2014 Toyota Prius v/5
Schneider EVlink L2 charging
EV driver since March 2013

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