Very High Electric Bill

[8lincoln30]

And I should note that during that minute of testing 40 amps to the Tesla, my voltage did drop to 235V or so. Those wires probably warmed up quickly. I wouldn't risk it above 24 amps and would caution anybody thinking of doing this that just because the car will let you draw 40 on a 30 circuit, don't be stupid and tempt fate.

 

[DarkMatter]

It will take a while to pop the breaker even at that much of an overload. In the meantime your 10 gauge wire (orange jacket) is dissipating around 20 watts/foot. Typical heat tape is around 9 watts/foot so you can imagine how warm everything will get.

 

[David29]

I pay between 8&9 cents/kwh at night, and only a penny more during the day, in NY, including delivery and taxes.

View attachment 219810

Impressive. What utility do you use?

 

[brucet999]

Installing a second meter is cheap and easy if your Tesla outlet is running off a subpanel. I bought this remanufactured meter online for less than $40 and the box was about $30 at Lowe's, I think. I felt comfortable installing myself given that I was working with a subpanel. The Tesla outlet is the only load connected to the meter so it's an accurate reading of only the electricity the car draws.

(Note: if you want to ensure it's up to code, etc, you can buy the parts and have an electrician do it. I am aware that my installation may not be perfectly up to code, but I have no qualms about its safety. I'm limiting the car to 24 amps because the subpanel itself was wired to a 30-amp breaker in the main panel. Feel free to suggest improvements that would comply with code, if necessary, but please don't admonish me for doing it myself.)

Your plan is not useful for OP. He was told that he could get a lower rate from the poco on a separate meter. That would have to connect directly to the poco wires, not behind any other meter.

 

[mmccord]

Impressive. What utility do you use?

NYSEG

 

[brkaus]

Your plan is not useful for OP. He was told that he could get a lower rate from the poco on a separate meter. That would have to connect directly to the poco wires, not behind any other meter.

OP may require a meter connected directly to the poco.

A separate connection to the poco isn't always required. It's up to the power company how it's configured. Austin, TX requires a meter between the main breaker and the EV load. Then they subtract it from the total.

Going to depend on the jurisdiction.

 

[mbhforum]

Well, it's been 3 days since I started measuring my electric usage and I am averaging 41 kWh per day and on pace for over 2400 kWh over 60 days which is even higher than my last bill. Granted it's the weekend and someoke was home both days. Still a small sample size. Below is the details but it's starting to look like vampire drain and preheating wasn't the issue. My wife hasn't really used her equipment much this weekend either. Ordered a Sense and it's on the way hopefully this week.

3/24 Friday 7am 11531 kWh
3/25 Saturday Noon 11575 kWh (+44 kWh charged car for 2.5 hours)
3/26 Sunday 7am 11592 (+17 kWh didn't charge car)
3/27 Monday 7am 11655 (+63kWh charged car for 4 hours 45 mins)

 

[brkaus]

Also... I don't think it's cooling season there yet, and not sure about your microclimate. But remember any heat put into the house via electronics may require air conditioning to take out.

Did your charging level out at a typical current/voltage?

 

[mbhforum]

Also... I don't think it's cooling season there yet, and not sure about your microclimate. But remember any heat put into the house via electronics may require air conditioning to take out.

Did your charging level out at a typical current/voltage?

Weather should not be a factor in my electric usage during the cold months. It's been in the 40's and 50's here in NY and I use hot water heat.

I set my charging rate to 36amps. When I set it to 40, the Tesla drops it to 30.

 

[thefortunes]

Well, it's been 3 days since I started measuring my electric usage and I am averaging 41 kWh per day and on pace for over 2400 kWh over 60 days which is even higher than my last bill. Granted it's the weekend and someoke was home both days. Still a small sample size. Below is the details but it's starting to look like vampire drain and preheating wasn't the issue. My wife hasn't really used her equipment much this weekend either. Ordered a Sense and it's on the way hopefully this week.

3/24 Friday 7am 11531 kWh
3/25 Saturday Noon 11575 kWh (+44 kWh charged car for 2.5 hours)
3/26 Sunday 7am 11592 (+17 kWh didn't charge car)
3/27 Monday 7am 11655 (+63kWh charged car for 4 hours 45 mins)

How many miles did you drive and what was the reported kWh usage between your previous charge and Saturday when you charged? Between the charge Saturday and the charge Monday am?

 

[brkaus]

Weather should not be a factor in my electric usage during the cold months. It's been in the 40's and 50's here in NY and I use hot water heat.

I set my charging rate to 36amps. When I set it to 40, the Tesla drops it to 30.

Agree on the cold months. What voltage are you showing when charging? (Amps * Voltage * Hours)/1000 will give you power consumed by the car. Should give you a rough estimate. Assuming 240V...

21.6 kWh to the car on Saturday reading
41 kWh to the car on the Monday reading

 

[mbhforum]

On Friday, I drove around 32 miles.

On Saturday, I drove around 15 miles.

On Sunday, I drove around 75 miles.

I believe my reported kWH usage range was around 400, give or take. I didn't officially record it though.

 

[mbhforum]

Agree on the cold months. What voltage are you showing when charging? (Amps * Voltage * Hours)/1000 will give you power consumed by the car. Should give you a rough estimate. Assuming 240V...

21.6 kWh to the car on Saturday reading
41 kWh to the car on the Monday reading

How do I find this information out? Lately, I've been charging at 1am and haven't been able to see it live. I don't think I can pull up any historical info, correct?

 

[thefortunes]

On Friday, I drove around 32 miles.

On Saturday, I drove around 15 miles.

On Sunday, I drove around 75 miles.

I believe my reported kWH usage range was around 400, give or take. I didn't officially record it though.

Using your numbers, you had significant vampire drain Friday but not Saturday/Sunday.

Friday 32 miles x 400Wh/mi = 12.8 kWh used which should take around 14 kWh to replenish. You took 21.6 kWh.

Saturday/Sunday 90 miles x 400Wh/mi = 36 kWh used which should take around 40 kWh to replenish. You took 41 kWh.

If you really want to solve this you need to record your numbers closely, both driving and charging.

 

[mbhforum]

Using your numbers, you had significant vampire drain Friday but not Saturday/Sunday.

Friday 32 miles x 400Wh/mi = 12.8 kWh used which should take around 14 kWh to replenish. You took 21.6 kWh.

Saturday/Sunday 90 miles x 400Wh/mi = 36 kWh used which should take around 40 kWh to replenish. You took 41 kWh.

If you really want to solve this you need to record your numbers closely, both driving and charging.

Thanks, but your not factoring in my other utilities in my house. 21khw from Friday to Saturday was my entire house AND my car being charged. I am going to keep a spreadsheet to track this better.

 

[thefortunes]

Thanks, but your not factoring in my other utilities in my house. 21khw from Friday to Saturday was my entire house AND my car being charged. I am going to keep a spreadsheet to track this better.

Nope. You said you used 44 kWh Friday 7am - Saturday at noon.

The 21 kWh calculation was shown by brkaus above:
36 amps x 240 volts x 2.5 hours / 1000 = 21.6 kWh for charging

 

[mbhforum]

Nope. You said you used 44 kWh Friday 7am - Saturday at noon.

The 21 kWh calculation was shown by brkaus above:
36 amps x 240 volts x 2.5 hours / 1000 = 21.6 kWh for charging

I am not 100% sure I was charging at 36 amps. It could have been 30, but since it happened overnight, I couldn't monitor it. I know I had it set for 36amps, but I have seen it drop back to 30 sometimes.

 

[thefortunes]

I am not 100% sure I was charging at 36 amps. It could have been 30, but since it happened overnight, I couldn't monitor it. I know I had it set for 36amps, but I have seen it drop back to 30 sometimes.

First, if you see it drop to 30 amps then you may have a wiring problem.

Best recommendation I have is sign up for TeslaFi and get the data you need to solve this. It will show your actual driving, vampire and charging info:

 

[mbhforum]

I was actually considering signing up for this, but I was afraid I was adding another variable to the mix. How often does it "wake up" the car to get statistics?

 

[brkaus]

I am not 100% sure I was charging at 36 amps. It could have been 30, but since it happened overnight, I couldn't monitor it. I know I had it set for 36amps, but I have seen it drop back to 30 sometimes.

Your right, I don't think you can know for sure what happened the duration of the session. But it does give you ballpark numbers to work with. I do believe that once it kicks down for a location it remains kicked down. I find chargepoints kick down for me (with all of my 4 days of experience )

Hopefully the sense will give you some idea. It may take a while to learn - if ever.

On my house, I used a watt meter on the main. Then walked around the house room by room turning things off. I found some super stupid stuff - like the remote receiver module for our ceiling fans takes 55 watts all the time power is available to it. No big deal, until you note I have 8 fans in the house.

Cold weather the car is going to use more power for short trip

Good luck!!! You will get it solved!