I need to ball park my charging cost for tax purposes. I have my lifetime whm number and factoring in 15% efficiency loss on charging what's the formula to convert into kWh?
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Easy conversion of whms to kWh?
- Thread starter Nocturnal
- Start date
Are you trying to convert Wh to kWh? divide by 1000. 1000Wh = 1kWh
Your question is lacking a bit of substance so I am just shotgunning an answer for ya.
Silicon Desert
Well-Known Member
I am assuming you mean whm to be Watt hours per mile? Where did you get that 15% charging loss? That is unrealistically high to me.
Yes, that's it. I was vastly over complicating this in my head. Doh.
I believe that's what I've seen tossed around.
Keep in mind the Wh/mi number in the vehicle is only while the car is in motion, does not include vampire drain. The actual "wall to wheels" number of energy consumption may be a bit higher than what is shown on your vehicle's lifetime statistic.
jdcollins5
Member
I have a kWH meter on the breaker going to my 14-50 receptacle. In these colder months I have been seeing 15-20% difference between the Trip Meter kWH and kWH Meter. This includes pre-heating and vampire losses. I would expect it to get closer to 10% with milder spring weather.
@Bighorn, a long time Tesla owner, recommends using the 15% number to be on the safe side.
Silicon Desert
Well-Known Member
85% charging efficiency.... ok I see you mention other people throw out that number and it might be correct. My personal experience has been better. At my electrical panel, I can monitor energy delivered to my car and compared that to what I actually got. I regularly see about a 7% loss on my X100 during the charge event. I charge at about 40 amps on my HPWC and realize that when charging at a higher current, there is greater loss. I suppose you can use the 15% number and may be correct and I doubt the tax man is going to dispute you ;-)
That's ok. I'm trying to be conservative anyway as I'm sure this is going to confuse the IRS as it is. With gas it's easy, just pull your gas bills.
I have a Sense that I will use for 2019 to give me an exact measurement of energy usage but for 2018 I have to estimate it.
SageBrush
REJECT Fascism
The car reports lifetime kWh. Divide by 0.88 for approximate metered electricity from home. A mixture of kWh from home and from Superchargers is trickier. Tesla helps by reporting total charges in your account on their website but you will have to estimate kWh. In my driving I average about 90 kW charging.
Example:
Say you accrued $50 of Supercharging during a tax year and you pay 25 cents a minute.
--> 200 minutes of Supercharging
----> At 90 kW average you gained 1.5 kWh a minute so 200*1.5 = 300 kWh
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