new user question regarding trickle charger cost

[hemaphore]

I tried to search for this but couldn't think of the right keywords to find an answer so I thought I would just post the question and get yelled at later

I just bought a 2013 Leaf and live in an apartment complex. My apartment is too far from my parking spot to run a cord to the car. My girlfriend, on the other hand, owns a house and has agreed to allow me to trickle charge there when I stay over on the weekends.
One, reasonable, stipulation is that I pay her back for the excess power usage.

I am no electric engineer by any means but I found this equation online: W = A*V

If that is true, then W = 120V * 12A
so W = 1440 or 1.4kW
So if I charge for 8 hours, that is 8h * 1.44kW = 11.52kWh
Electricity in her area is $0.09/kWh so 11.52*.09 = ~$1.04

So is it true that if I charge my Leaf at her house for 8 hours, I only owe her $1.04?
Seems a little low to me but if someone could validate my math that would be great!!!

Thanks!

 

[DaveEV]

If that is true, then W = 120V * 12A
so W = 1440 or 1.4kW
So if I charge for 8 hours, that is 8h * 1.44kW = 11.52kWh
Electricity in her area is $0.09/kWh so 11.52*.09 = ~$1.04

So is it true that if I charge my Leaf at her house for 8 hours, I only owe her $1.04?
Seems a little low to me but if someone could validate my math that would be great!!!

You are correct.

 

[mbender]

So is it true that if I charge my Leaf at her house for 8 hours, I only owe her $1.04?
Seems a little low to me but if someone could validate my math that would be great!!!

You are correct.

I'd give her at least $1.10 though, just to stay on her good side.

 

[cgaydos]

If that is true, then W = 120V * 12A
so W = 1440 or 1.4kW
So if I charge for 8 hours, that is 8h * 1.44kW = 11.52kWh
Electricity in her area is $0.09/kWh so 11.52*.09 = ~$1.04

So is it true that if I charge my Leaf at her house for 8 hours, I only owe her $1.04?
Seems a little low to me but if someone could validate my math that would be great!!!

You are correct.

This is when the light bulb over the head comes on for a lot of people. "Wait a minute - you just charged your car full up for the price of about a half of a gallon of gas????"

 

[EVDRIVER]

You should round to $1.05. :lol:

 

[LEAFer]

Electricity in her area is $0.09/kWh so 11.52*.09 = ~$1.04

What everyone else said

But I want to comment on your sentence quoted above. You need to know the ACTUAL cost for her. "in her area" is *NOT* good enough. It's possible she is on a TOU (Time-Of-Use) system. It's also possible she is on a "Tiered" system. In either case, her actual cost could be significantly higher, depending on WHEN you charge, or HOW MUCH the extra electricity use is (could push her into a more expensive higher tier.) And, finally, the higher use also may add additional cost (taxes, solar or renewable energy fees, all of which may be based on total kWh use).

Take a look at her electric bill and her utility provider's rate sheets.

HTH.

 

[TomT]

But in all fairness, it should be pointed out that electricity costs in many parts of the country are many times the OP's amount...

This is when the light bulb over the head comes on for a lot of people. "Wait a minute - you just charged your car full up for the price of about a half of a gallon of gas????"

 

[DaveEV]

This is when the light bulb over the head comes on for a lot of people. "Wait a minute - you just charged your car full up for the price of about a half of a gallon of gas????"

Well, you are comparing the equivalent of 1-2 gallons of gas, so not the same as a full tank.

I had a Model S visitor last night - charged up 65 kWh good for about 200 miles - utility cost of about $10 (14-16c / kWh). Still $6 cheaper than fueling a Prius and a fraction the cost of fueling a similar gas powered car.

 

[Reddy]

I'm not sure you want let it get around that you're paying your girlfriend.