[dustinroyer]

I have a Grizzl-E charger hardwired on a circuit protected with a 50 amp breaker. I set it to draw 40 amps, according to the
charger’s owner’s manual. When charging, the car reports that it’s adding 32 MPH.

According to Tom Moloughney here, 32 MPH corresponds to a 48 amp draw (at the US standard 240 volts.)

Being concerned about overloading the circuit, I lowered the Grizzl-E’s draw to what the manual claims is 32 amps. After doing so, the car reports adding 27 MPH, corresponding to Tom’s 40 amp charging experience.

All that to ask: is there a way to convert the MPH report on the car to kilowatts, so that I can figure how many amps the car is drawing? (I don’t have a strong enough ammeter; otherwise, I’d just measure it directly.)

 

[theboomr]

There is (very frustratingly) no way to have a kW display for charging on the car screen, only the mph. And btw, the mph is based on your GOM and recent efficiency, so that 32 mph might still have been just for 40 amps.

 

[ChristophW]

It’s likely that you drive more efficiently than Tom does. I find it hard to believe that the settings in the Grizzl-E would be so off target (dangerous) or so easy to get wrong - also dangerous, and therefore unlikely in a UL- listed device.

 

[John411iD]

All that to ask: is there a way to convert the MPH report on the car to kilowatts, so that I can figure how many amps the car is drawing? (I don’t have a strong enough ammeter; otherwise, I’d just measure it directly.)

Any elm327 adapter and free Car Scanner Elm Obd2 app will show the amps, volts and kW while charging or driving, plus the temperature of the battery pack.

 

[jgoodnough]

I have a Juicebox Pro ESVE set to charge at 32 amps instead of 40. My car also reports 27 mph of added range when charging. Perhaps Tom M's datapoints were shown incorrectly?

 

[Enzo589]

I have a Juicebox Pro ESVE set to charge at 32 amps instead of 40. My car also reports 27 mph of added range when charging. Perhaps Tom M's datapoints were shown incorrectly?

As [mention]theboomr [/mention]said, the mph added is based on the system’s gom and your driving habits, so it will vary. I also have a Grizzl-e and I’m at 24 amps with my mph being around 21. A week before that, it was at 18. So, based on previous driving habits, that mph number will change.

 

[jgoodnough]

As [mention]theboomr [/mention]said, the mph added is based on the system’s gom and your driving habits, so it will vary. I also have a Grizzl-e and I’m at 24 amps with my mph being around 21. A week before that, it was at 18. So, based on previous driving habits, that mph number will change.

I'm going to guess that the GOM data used is based upon the "long-term" number shown in the "data" screen? I would hope VW would choose a car's long-term data (and thus the average driving style of that particular operator) versus last-drive since that could have been someone's lead-footed 17 year old son/daughter!

 

[Enzo589]

I'm going to guess that the GOM data used is based upon the "long-term" number shown in the "data" screen? I would hope VW would choose a car's long-term data (and thus the average driving style of that particular operator) versus last-drive since that could have been someone's lead-footed 17 year old son/daughter!

That’s something we have all been trying to figure out. You’ll probably come across other topics in this forum where there are discussions about how the gom is calculated. I believe it’s something we will never truly know the formula for, as these companies may not want to share how they calculate it. But, I think the best way to calculate how far the car can go is just by driving it for a while. Over time, you will start to realize how far you can go on a charge and how your different habits may affect the range….at least that’s what I’ve read! This is my first EV and I’ve only had it for a month.

 

[dustinroyer]

I guess I need to try my OBD reader to see if it will read the necessary info or invest in one that will.

 

[Nai3t]

Ignore the miles per hour figure.

Look at state of charge instead.

40 amps gains about 13% per hour.

 

[Tinman]

(40 Amps X 240 V) = 9600 Watts divided by 100 divided by your 'Vehicle-->Data' screen's miles per kWh should approximately equal your Charging MPH reported. I use Long Term.
(Plug in your actual voltage at your EVSE, if you know it. During summer, 240 Volts is optimistic)

(40*240)/100/3.3=29.1

For a 48 Amp setup for ID.4:
(48*240)/100/3.3=34.9

For my 16 Amp right now, actual voltage is 219 Volts, long term 3.2 kWh/mile:
(16*219)/100/3.2= 10.95 mph
My display is showing 11 mph

I agree, there's a better way. But, this works for now.

 

[jgoodnough]

That’s something we have all been trying to figure out. You’ll probably come across other topics in this forum where there are discussions about how the gom is calculated. I believe it’s something we will never truly know the formula for, as these companies may not want to share how they calculate it. But, I think the best way to calculate how far the car can go is just by driving it for a while. Over time, you will start to realize how far you can go on a charge and how your different habits may affect the range….at least that’s what I’ve read! This is my first EV and I’ve only had it for a month.

I had a Kona Electric for two years before the ID4. Both that car and the ID4 GOM's were remarkably accurate for me overall. Like 1-2 miles off after 200 miles of mixed driving on city/secondary/interstate roads. I'm a fairly "sedate" driver though.

 

[Cascade Steve]

(40 Amps X 240 V) = 9600 Watts divided by 100 divided by your 'Vehicle-->Data' screen's miles per kWh should approximately equal your Charging MPH reported. I use Long Term.
(Plug in your actual voltage at your EVSE, if you know it. During summer, 240 Volts is optimistic)

(40*240)/100/3.3=29.1

For a 48 Amp setup for ID.4:
(48*240)/100/3.3=34.9

For my 16 Amp right now, actual voltage is 219 Volts, long term 3.2 kWh/mile:
(16*219)/100/3.2= 10.95 mph
My display is showing 11 mph

I agree, there's a better way. But, this works for now.

It should be divided by 1,000 for kilowatts. Your calculation are wrong by a factor of 10.

 

[d287]

I know this is an old thread, but rather than start a new one, I noticed something new today… am plugged into a Tesla wall connector at a supermarket using my Tesla Tap. Anyway, the car says 30mph charge speed, and when I tap the Data tab, it shows -43.2kWh. So, apparently it does read out the charging rate in watts, just not on the Charging screen! (Note: I am sitting in the car while the boss shops and an running the climate control while charging since parked in the sun.)

 

[dustinroyer]

Well, my grandmother was right when she said you learn something new every day whether you want to or not.

 

[Nai3t]

Interesting! Nice find. I'm curious, though... 43.5 kW is not a L2 charging rate. The ID.4 caps out at 11 kW.

 

[d287]

Interesting! Nice find. I'm curious, though... 43.5 kW is not a L2 charging rate. The ID.4 caps out at 11 kW.

Good point! In my head, I was thinking amps, I suppose… maybe just chalk this one up to a software glitch? Because I think in the past I’ve seen it at zero when charging…

 

[Tinman]

Wouldn't -43.2 kWh/h = -43,200/60 = somehow correlate to the 7.2 kW that a 30 Amp EVSE is supplying to the car per hour?

 

[Nai3t]

@d287 I was thinking Amps at first, too! I was scratching my head why it wasn't closer to the standard 40A or 48A rate (unheard of at most public charging locations).

@Tinman it should be 43,200 kW / 240volts = 180 amps! That's a touch on the high side.

 

[Huey52]

Be reminded that the volts is multiplied by the Power Factor. Ideally unity but not always dependent on quality of transmission infrastructure (capacitor banks to help achieve, etc).

@d287 I was thinking Amps at first, too! I was scratching my head why it wasn't closer to the standard 40A or 48A rate (unheard of at most public charging locations).

@Tinman it should be 43,200 kW / 240volts = 180 amps! That's a touch on the high side.