Anyone using Juice Box?

last night I took 21.49 in 118 minutes from the Juicebox

I couldn't say for sure, but that's faster than the car can charge (10.93kw). What I'm guessing is that is wall power, and not what is actually taken in by the car battery.

I believe the efficiency factor, as per Tony is about 83.3% (charging is not 100% efficient). With that I would easily believe that your car is charging at about 9.1kw?

The Tesla charger is weasel worded to be 10K. That is 250V and 40A. My 240V is certainly not 250VAC. I do have a KW meter on my charger and at 245V I have seen over 9.6KW from the wall.

GlennD said:

The Tesla charger is weasel worded to be 10K. That is 250V and 40A. My 240V is certainly not 250VAC. I do have a KW meter on my charger and at 245V I have seen over 9.6KW from the wall.

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Yes, it should be 9.6kW, but the voltage tolerance is 216-264 volts (240 +/- 10%).

The 40 amps is maintained to 250 volts, and at 250 volts, it will maintain 10kW up to 277 volts. That's something very unique about the Tesla charger... 277 volts.

rdavis0521 said:

I couldn't say for sure, but that's faster than the car can charge (10.93kw). What I'm guessing is that is wall power, and not what is actually taken in by the car battery.

I believe the efficiency factor, as per Tony is about 83.3% (charging is not 100% efficient). With that I would easily believe that your car is charging at about 9.1kw?

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It's not even wall power. The Tesla charger will not pull more than 10kW from the wall, so about 8.2kW to 8.5kW into the battery.

It any EVSE is "measuring" otherwise, I'll just suggest that it's quite wrong.

So now I am confused. Are you saying that effectively the car can only charge at a max of 8.2 a 8.5 kW? There is no way to get 10kw to the battery, regardless of EVSE capacity?

I have JuiceBox Pro and I have analyzed the charging session stats it reports and they are typically 5% lower than what's reported by my utility company for the charging session. So, JuiceBox does not provide accurate actual wall or battery power stats. I am guessing the stats represent power delivered from the JuiceBox to the onboard charger.

rdavis0521 said:

So now I am confused. Are you saying that effectively the car can only charge at a max of 8.2 a 8.5 kW? There is no way to get 10kw to the battery, regardless of EVSE capacity?

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Yes, the actual energy added to the battery is:

(amps * volts from the wall) * 85% charger efficiency (varies slightly based on battery temperature, cell impedance, charge rate creating more or less cooling / heating of the cells, etc.)

So, using a JESLA at 40 amps * 240 volts = 9.6kW * 85% onboard charger efficiency = 8.16kW into the battery

Using a generic 3.0 miles per kWh consumption rate shown on the dash multiplied by 9.6kW will give you 28.8 miles per hour while charging.

Using our corrected factor of 1.2 means that 3.0 miles per kWh from the dash is 3.6 miles per kWh consumption rate from the battery multiplied by 8.16kW = 29.3 miles per hour charging.

See how 28.8 and 29.3 are nearly identical?

evnewbie said:

I have JuiceBox Pro and I have analyzed the charging session stats it reports and they are typically 5% lower than what's reported by my utility company for the charging session. So, JuiceBox does not provide accurate actual wall or battery power stats. I am guessing the stats represent power delivered from the JuiceBox to the onboard charger.

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Yes, that data is inaccurate by any measure.

Just got my MB delivered yesterday, and installed JuiceBox today on the 240v 32A line.

First readings from the "Power Last Session" shows 7.35kW.

Question: when you "Edit" you box on the webpage, on the Amp setting window, is this really setting up (programming) your JuiceBox? Like this amount of current it will draw from the line (electric outlet)?

Also still confused how to delay charging for night time...

http://lmgtfy.com/?q=how+do+i+schedule+my+juicebox+to+charge+at+a+specific+time%3F