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Hi all

First post on the Forum - I bought a new Volt on Saturday and absolutely love it already.

I live in a co-housing community where the electricity used in the garages and in the common areas of the complex is communal and paid for by the whole community (there are 10 garages in total). Now that I am drawing >10kWh a night it's only fair that I pay a bit extra to cover the additional power usage. I do not use the Volt every day and some days there is quite a bit of charge left from my commute depending on temperature, driving style etc..

My question is, is there a straightforward way for me to work out on a monthly basis how much power I have drawn from the grid so I can reimburse other community members the correct amount? I rent the condo so don't want to install a new meter etc.. The Volt provides info on the total kWh from the last charge (which I don't think includes the power used in charging) but doesn't seem to provide a total kWh drawn number.

My best approach at the moment is to write down how many kWh I have drawn for each charge (but I don't know if this includes the additional kWh used in charging) and tally them up at the end of the month.

I'm sure there must be other people in similar circumstances - any ideas appreciated.
 

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I know a few people that used a "P3 International Kill a Watt" meter to get a reading on how much power it took to charge their Volt. I recommend you only use it a few times since it isnt rated to have that much juice flowing thru it on a constant basis (15amp max rating). The volt charger takes a constant 14amps or so.

Congrats on your Volt. I love mine.
 

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Hi all

First post on the Forum - I bought a new Volt on Saturday and absolutely love it already.

I live in a co-housing community where the electricity used in the garages and in the common areas of the complex is communal and paid for by the whole community (there are 10 garages in total). Now that I am drawing >10kWh a night it's only fair that I pay a bit extra to cover the additional power usage. I do not use the Volt every day and some days there is quite a bit of charge left from my commute depending on temperature, driving style etc..

My question is, is there a straightforward way for me to work out on a monthly basis how much power I have drawn from the grid so I can reimburse other community members the correct amount? I rent the condo so don't want to install a new meter etc.. The Volt provides info on the total kWh from the last charge (which I don't think includes the power used in charging) but doesn't seem to provide a total kWh drawn number.

My best approach at the moment is to write down how many kWh I have drawn for each charge (but I don't know if this includes the additional kWh used in charging) and tally them up at the end of the month.

I'm sure there must be other people in similar circumstances - any ideas appreciated.
I get my usage from MyVolt.com using my OnStar Account. You can download a file (*.csv) that can be converted into an Excel Spread Sheet.
 

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Myvolt dot com will give you consumption over the last 30 days.
 

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I know a few people that used a "P3 International Kill a Watt" meter to get a reading on how much power it took to charge their Volt. I recommend you only use it a few times since it isnt rated to have that much juice flowing thru it on a constant basis (15amp max rating). The volt charger takes a constant 14amps or so.

Congrats on your Volt. I love mine.
You are correct in that the kill a watt meter is not rated for long term use. The Voltec charger cannot pull more than 12A as per the electrical code.

Another simple way is to see the estimate for full charge in hours and multiply by 1.45KW if charging at 12A on 120V. That should get you very close.
 

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I get my usage from MyVolt.com using my OnStar Account. You can download a file (*.csv) that can be converted into an Excel Spread Sheet.
If you do this, I'm pretty sure you'll have to multiply the figure on MyVolt.com to account for charging losses. On a couple tests I did, I found that the charger takes about 24% more energy than what is reported by the car itself. This number will be even higher if you pre-condition the cabin or the TMS kicks in much.

[EDIT: Actually, I think I'm wrong about this.]
 

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You could use Trip meter B to accumulate total miles and gas. Then back out your gas miles based on your average mpg on gas (37mpg for me). You should also know your average E-miles per charge (40 for me). A full charge at 120V is roughly 13.5kwh. This would give a reasonable total kwh draw from the wall. It should get you within a dollar +/-. From the sound of your situation, this should suffice and be an easy way to keep track. I'm a little skeptical on On Star or other reported data as I've seen inaccuracies.
 

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We calculated my charger at work to only use about $20 per month. It's not that much unless you always charge it fully depleted 7 days per week... You can figure it out pretty easily by assuming you get about 4 miles per KWH.....

MrEnergyCzar
 

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I would offer to pay them an annual amount and get something in writing that the board agrees so that no one can come back on you. Technically though, is anyone else required to pay if they plug anything in to the common plugs? Anyone use block heaters etc. You are already paying something for those outlets in your condo fees so I would offer $15 - $20 per month to keep them pleased and then offer to review it periodically and adjust up or down as required. When someone else gets an ev they will then know what to expect.
 

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If you do this, I'm pretty sure you'll have to multiply the figure on MyVolt.com to account for charging losses. On a couple tests I did, I found that the charger takes about 24% more energy than what is reported by the car itself. This number will be even higher if you pre-condition the cabin or the TMS kicks in much.
After reviewing my onstar data, I think I was wrong on this. I see a few charges with 13 and 12 kwh's, so I guess it's reporting the actually number drawn from the outlet.

I wonder if anyone has used a TED of Kill-A-Watt to verify the accuracy of these figures(?).
 

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After reviewing my onstar data, I think I was wrong on this. I see a few charges with 13 and 12 kwh's, so I guess it's reporting the actually number drawn from the outlet.

I wonder if anyone has used a TED of Kill-A-Watt to verify the accuracy of these figures(?).

I've verified my with a Kill-a-Watt.. (modulo its rounding, it was on the mark).


Personally though I use my voltstats data as myvolt.com has been a bit flakey, e.g. while I got a august report via email, I cannot see the data for the last 30 days on the site. If you setup something with the board and you cannot produce the data, that would be bad. I've never had a problem with voltstats.net So if you go with onstar, you might use voltstats.net as a backup in the plan. An even simpler thing for them to verify, but far less accurate, is using the car's odometer and overall MPG.
 

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myvolt.com is rife with errors, so you proably won't be able to rely on the data. For example, I plugged in my car and immediately unplugged it. It showed the date and time, 0 hrs 0 mins, but it added 7kW-hr to my usage data! This has happened multiple times so it's no fluke. Nice bunch of programmers they have. And don't get me started on the Onstar RemoteLink app...
 

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The plastic on my Killawatt melted and stuck to the wall and the EVSE plug. Fire Hazard!
 

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If I was going to use a kill-a-watt device for 10 + hours at 12 amp - I would test it first- Even open it up and check the inside connections to the main board. When I used mine long term ( 8 amps ) I used a 3 foot extention cord ( at the very least I had a better heat sink)
 

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Should be just amps * volts * charge time = KWH / price per KWH = cost

So all you really need to keep track of is how long the car charges for. We know that the Max is 12amps on the L1 charger so worse case use that. I verified mine with a meter for 30 minutes and it stayed at 1440 Watts.
 

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aes256, from my PG&E usage report I can see that the charging power tapers off in some fashion. I would like to connect a watt-hour meter that would give me a number for all the watt-hours into the Voltec 240V charger.
 

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I get my usage from MyVolt.com using my OnStar Account. You can download a file (*.csv) that can be converted into an Excel Spread Sheet.
Same here. That is the easiest wat to calculate your costs.
 
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