Charging the Roadster

[Ben W]

In the most extreme example, I charged the car from "emtpy" (0 miles in Standard Mode, 25 in Range) for 24 hours once. When I came back to the car, the VDS showed only 64 ideal miles. I drove the car about 10 miles, parked it, and came back to the car an hour later. The VDS now showed around 120 ideal miles!

I was told that the mobile connector doesn't have the ability to fully charge the car in Range mode, but I let it charge that way overnight as a test, and came out this morning to find 247 ideal miles on the display, an hour after it finished charging. (And the "Top Off" button still available.) Has anyone seen a higher number?

 

[Tdave]

I know some people with an HPC keep it set at 40 amps instead of 70 amps to minimize heat during the recharge process. But 12 amps would seem to be too slow and perhaps inefficient.

I have always thought that 240 volts and 30-40 amps is the sweet spot for efficient charging. Not too fast (heat) and not too slow (inefficient).

Personally I think 24A at 240V is a great place to be, especially in ambient near 80F.

I agree with 24A. When I use 40A I'll notice the front fans being used at times during the charging process. They're loud, so it's noticeable. When I use 24A that almost never happens. So I use 24A for day to day charging. Plenty fast charging for me.

 

[ChargeIt!]

Maybe that's not a bug, ... maybe it is an "easter egg".

1.21 Gigawatts and all.

At Menlo Park today ...

2nd Edit: back to Thumbnail.

 

[vfx]

image does not show^

 

[ChargeIt!]

image does not show^

Wow! You're right ... after I cleared by browser's cache I saw that too. I thought I followed TEG's instructions, but may have goofed ... for some reason after I upload a JPG it's always just a thumbnail. For now, I will switch back to Thumbnail.

Edit: I'll have to check three other places I tried that "TEGnique" ...

 

[TEG]

ChargeIt!, when you add an embedded image link to an image you uploaded on this site you still need to keep the thumbnail (in a post somewhere) or else they will both disappear.

 

[ChargeIt!]

ChargeIt!, when you add an embedded image link to an image you uploaded on this site you still need to keep the thumbnail (in a post somewhere) or else they will both disappear.

Thanks, that explains it. I had substituted the image for the thumbnail, not realizing BOTH are required. Since you show the full image I won't edit this one again.

 

[vfx]

Funny picture though.

 

[dpeilow]

OK here's how you show an uploaded image as a main picture:

1. Upload the image when you create the post.
2. "Preview" the post so that the image shows as a thumbnail in the preview post.
3. Click on the thumbnail so that it opens as the full image in a separate tab.
4. Copy the URL of that full image. It should end in .jpg, .gif, .png or a similar image file format.
5. Go back to the edit field of your post on the first tab. Copy the full image url between the tags as you would for another external image.
6. Submit the post.

 

[scott451]

I agree with 24A. When I use 40A I'll notice the front fans being used at times during the charging process. They're loud, so it's noticeable. When I use 24A that almost never happens. So I use 24A for day to day charging. Plenty fast charging for me.

Any 2008 owner interested in running some test cases? If someone will run the following test cases and send me the log dumps, I'll process the results and upload the results...


It would take quite a while to collect the data, but here's what's needed

In standard mode:

• Deplete the battery to < 50%
• Charge at 240V@12A for 30 minutes. (cools battery to 18C)
• Stop the charge.
• Charge to full at the test current (e.g. 12A)
• Dump log to usb
• Log KWh meter reading if you have it
• repeat for 16,24,32,48,64,70

I'll provide a spreadsheet/plot with Time vs.:

• Line voltage
• Line current
• ESS current
• ESS voltage
• SOC
• ESS temp

-Scott

 

[ChargeIt!]

I have info from a Tesla tech that charging, then stop charging, and then resume charging may not capture (known bug) the first part of the session on the ChargeSessionHistory ("CSH") screen unless the car is driven between sessions. I can only assume that also applies to the log, but not sure. Before spending much time on this "test" verify what your firmware will do. I also believe there's a bug that if you open/close the charge port WITHOUT charging, then the CSH data gets wiped out (on the VDS). It does not make sense that it is lost from the logs also, but it's best to check that behaviour too.

The 121kWh case (?1.21 jigawatts :biggrin is still being reviewed by Tesla.

Firmware rev needs to be identified for any tests. I don't know if the logs keep track of what firmware was used to log a particular set of data ... but different set of F/W should be rare unless data from a large range of dates is being analyzed.

 

[scott451]

I have info from a Tesla tech that charging, then stop charging, and then resume charging may not capture (known bug) the first part of the session on the ChargeSessionHistory ("CSH") screen unless the car is driven between sessions. I can only assume that also applies to the log, but not sure. Before spending much time on this "test" verify what your firmware will do.

The VDS is pretty limited. None of the data in the log is generated by the VDS. It doesn't have access to the complete data. The log files generated by the VMS are much better. I have verified that the logs correctly record small charging events. My example was a trip to Pasadena, the CSH showed a single 5hr charge of 34KWhrs, whereas the log dump showed it correctly as two different charge sessions (charge, 15min drive, charge).

Firmware rev needs to be identified for any tests. I don't know if the logs keep track of what firmware was used to log a particular set of data

The firmware version is recorded regularly in the log.

-Scott

 

[dpeilow]

Tesla Charge at Airport Plug Shows EV Drivers Are Resourceful - Green Car Reports

 

[vfx]

Tesla Charge at Airport Plug Shows EV Drivers Are Resourceful - Green Car Reports

Marc responds
Plugs and Cars

 

[malcolm]

Wishlist: Background recharging

We know that low charge levels and slow recharge rates reduce energy consumption and improve battery life. The following idea assumes that the car is plugged in regularly - ideally but not necessarily every night.

Here's the idea;

Over the weeks and months the car learns the owner's typical daily mileage and by default, reduces the charge level and recharge rates to cover the next day's likely mileage (plus any likely overheads such as air con / heating and an extra 5% or maybe 10% depending owner's range confidence/anxiety)

If the car knows that weekend mileage is typically higher, it can start to increase charge levels across Wednesday/thursday/friday nights, reducing "Friday Night Grid/Battery Stress" caused by higher recharge currents.

Obviously this basic level of "background charge" based on previous driving behaviour can be overridden by the owner at any time - for example, if they know that they will be unable to recharge for the next few evenings.

As far as the owner is concerned all of this could appear as a simple choice presented on the VDS touch screen:

"Accept default recharge for tonight / Set tonight's recharge"

 

[vfx]

Wishlist: Background recharging

"Accept default recharge for tonight / Set tonight's recharge"

Worth putting in the Whitestar wishlist.

 

[JRP3]

I think in most cases it would be unnecessary. In most cases your pack will be shallow cycled and low rate charging is all you need. You know the amount of charge and how fast you need it before any automated system will. With my conversion I can dial in my charger for different rates, from 1 amp at 120 volts to 30 amps at 240 volts. Even my highest rate is pretty low and won't stress the cells, but if I had higher capability I still don't see the need to automate it.

 

[Doug_G]

Tesla Roadster Foundry cables

I notice the links seem to no longer work for the Tesla Roadster Foundry cables...?

 

[doug]

I notice the links seem to no longer work for the Tesla Roadster Foundry cables...?

Perhaps they're no longer available?? Hopefully James can let us know.

 

[AndrewBissell]

Rfmc awol

I had also noticed that. I was just gearing up to order a Euro-spec RFMC. I hope there isn't some fundamental problem here.