Firmware 4.5

[boilerbots]

Well, I went to triggered the update and I went from 1.33.38 to 1.33.51 with the same release notes as before. The update must have been minor, I sat in the car during the process and it was strange. I could hear various relays clicking and pumps cycling off and on, felt like I should put on my seat belt just in case!

 

[ken830]

Todd... If the energy usage really were minimal, then why would we even be discussing using shore power at all? It's minimal, right? I sure don't want to go to the garage to unplug the car before every pre-heat or pre-cool.

 

[tomas]

My car was delivered with 4.5 several weeks ago and tonight it prompted me for an update, but to what is it updating?

I wish I could read the release notes before it updates.

Use the forum. If you browse new release threads like this one you will see that release notes were posted.

 

[Todd Burch]

Todd... If the energy usage really were minimal, then why would we even be discussing using shore power at all? It's minimal, right? I sure don't want to go to the garage to unplug the car before every pre-heat or pre-cool.

Read my post again. I said it's minimal for touchscreen/radio usage. I did acknowledge that power usage is higher for preheat and precool.

 

[tomas]

For me, the Model S is an amazing experience - Combination of power, comfort, and amenities is unprecedented even at that price tag, and then there's the bonus of electric power: fast, immediate, quiet, inexpensive, and (with solar panels) completely sustainable. And, software driven design gives me new features and bug fixes every month or two, delivered over the air. Oh, and looks hot too!

I just cannot comprehend anyone who buys this car and then gets furiously wound up over some simple thing like possibility of spending an extra dollar a day on peak TOU costs to take advantage of shore power until Tesla makes it optional (which they surely will), or freaks out because they're going on vacation before downloading 4.5 and have to go another week or two maintaining 90% charge.

For me, this is a most excellent adventure, and when I encounter a bump in the road (for me, a rash of tire blowouts - I'm convinced the continentals and 21" wheels have fit flaw making them prone...), I just go for a drive, put back the roof, zoom past a couple of german cars, crank up the stereo, and that stuff seems inconsequential.

I guess some people just don't want to be happy??!!!???

 

[ken830]

Bottom line is TOU is a perfect match for electric cars. It helps keep the grid properly-sized and prevents over-loading, which saves EVERYONE money in the long run and prevents brown-outs/black-outs. We should make it easier (not harder) to take advantage of off-peak rates.

Read my post again. I said it's minimal for touchscreen/radio usage. I did acknowledge that power usage is higher for preheat and precool.

I read it three times. You acknowledged that it is more significant, but then you go on and minimize that as well...

The only reason that I can afford the Model S is because off-peak electric power is about 1/3 the price of gasoline per mile. But the peak electricity rates is much more than 3x that of off-peak. This is a significant difference.

And it's not something we're asking Tesla to add. Because it's been working fine the way it is (pre-4.5)... We're just asking them to not take it away.

I just cannot comprehend anyone who buys this car and then gets furiously wound up over some simple thing like possibility of spending an extra dollar a day on peak TOU costs to take advantage of shore power until Tesla makes it optional (which they surely will), or freaks out because they're going on vacation before downloading 4.5 and have to go another week or two maintaining 90% charge.

I don't see anyone freaking out. I just see people stating that this should be optional/configurable. I know it's not going to be $1 per day, but I still don't understand how you can say $1 per day is not significant. That's $28-$31 per month. I'm only expecting to spend about $50/month to power the car 70 miles per day. If that changes to $80, then that's significant. It's unlikely that a 60% increase is insignificant in any situation.

 

[tomas]

Right... Just saying... put it out there that Tesla needs to make it optional (you and others have!). I'm pretty sure they watch this forum. Trust that they will give you the option before you've spent much. Go for a drive and have fun!

 

[mknox]

And it's not something we're asking Tesla to add. Because it's been working fine the way it is (pre-4.5)... We're just asking them to not take it away.

Actually, it hasn't been working well. Some owners on 4.4 and prior releases claimed that the car did draw shore power for pre-heating and pre-cooling, but mine never did. In the dead of winter, the car would charge up, shut off then cold-soak until I was ready to go. Once I set out, my range had dropped significantly and I was chewing up battery power at a furious rate just warming up the cabin and (mainly) the battery. This used to drive me nuts when I'd use my phone to pre-heat and the car would start depleting the battery even though it was still plugged in! This starts to become a serious range issue when the temps are way below freezing, the roads are snow covered and I have 100+ miles to go. I'll gladly pay the premium for mid or on peak shore power to warm and condition the car before setting out, rather than risk being stranded.

Personally, I have not seen the car draw shore power on 4.5 unless I actively did something to make it happen (i.e. get into the car while plugged in or activate pre heat/cool from my smartphone). I have an energy monitor on that circuit and pay pretty close attention to the logs. I suppose Tesla could make a configuration option, but as long as you don't actively do something to cause power draw, you should be okay.

 

[wraithnot]

Everyone else with 4.5 may have already noticed this, but if you go to the charging screen while the car is plugged in, but not charging it will show you how much current it is pulling from the wall for heating, cooling, etc. I have 4.5 build 1.33.44 and I was adjusting the charge level down after some longer than normal drives on Sunday and Monday and I noticed the car was pulling about 5 amps even though it wasn't charging. By turning the heater up to high, I was able to get it to pull 20 amps at 237 volts.

 

[Todd Burch]

Personally, I have not seen the car draw shore power on 4.5 unless I actively did something to make it happen (i.e. get into the car while plugged in or activate pre heat/cool from my smartphone). I have an energy monitor on that circuit and pay pretty close attention to the logs. I suppose Tesla could make a configuration option, but as long as you don't actively do something to cause power draw, you should be okay.

I agree. I don't believe regular battery thermal management (which seems pretty passive when parked unless in extreme temperatures) ever draws from shore power. I haven't seen it either.

 

[hans]

Everyone else with 4.5 may have already noticed this, but if you go to the charging screen while the car is plugged in, but not charging it will show you how much current it is pulling from the wall for heating, cooling, etc. I have 4.5 build 1.33.44 and I was adjusting the charge level down after some longer than normal drives on Sunday and Monday and I noticed the car was pulling about 5 amps even though it wasn't charging. By turning the heater up to high, I was able to get it to pull 20 amps at 237 volts.

wow. 20 A * 238 V = 4.76 kW

That is a heavy duty electric heater! That's like three 1500Watt electric space heaters all cranked up to max at the same time. You can heat a house with that much power.

 

[mknox]

That is a heavy duty electric heater! That's like three 1500Watt electric space heaters all cranked up to max at the same time. You can heat a house with that much power.

Well, maybe in California

I think I've seen the power meter go up to 8 or 10 kW when standing still in freezing temps. I assume this is the cabin heat and the pack heater combined. Might have even been a bit higher.

 

[Bifff67]

Elon in a recent talk said the heater was 6KW. So makes sense.

 

[mitch672]

I am now even further agravated with 4.5

In the past (read: 4.4), I was able to overide the "60A" setting when using my 75A OpenEVSE, well on R4.5, it now has stopped that behaviour.

I plug in my OpenEVSE, it adjusts down to 60A, I go in and manually move it up to 75A (I have to dismiss the warning about the HPWC), and I think everything is great.

It isn't. When I check in the morning (when my delayed timer kicks in), its charging at 60A, so even though I overode the setting and moved it up to 75A, Tesla now chooses to ignore that, and "protect me" by dumbing down the setting (again) to 60A.

Again, don't ask why I need to charge at 75A, I don't, and I am only charging to %70 SOC everyday, since I don't need the range most days, but i paid for dual chargers, and if I choose to charge at 75A, there is no reason to prevent me from doing so. Tesla, you do not have the only high current EVSE in the world, there are people using other high current EVSEs, and you are preventing all of them from charging at over 60A as well.

Please put a switch on the menu page to disable the 60A automatic charging limitation, I want my charging session done as quickly as possible to minmize charger losses. I paid for dual chargers, I don't have a HPWC, and there is no reason I need to be "protected from myself".

 

[boilerbots]

I am now even further agravated with 4.5

In the past (read: 4.4), I was able to overide the "60A" setting when using my 75A OpenEVSE, well on R4.5, it now has stopped that behaviour.

I plug in my OpenEVSE, it adjusts down to 60A, I go in and manually move it up to 75A (I have to dismiss the warning about the HPWC), and I think everything is great.

It isn't. When I check in the morning (when my delayed timer kicks in), its charging at 60A, so even though I overode the setting and moved it up to 75A, Tesla now chooses to ignore that, and "protect me" by dumbing down the setting (again) to 60A.

Again, don't ask why I need to charge at 75A, I don't, and I am only charging to %70 SOC everyday, since I don't need the range most days, but i paid for dual chargers, and if I choose to charge at 75A, there is no reason to prevent me from doing so. Tesla, you do not have the only high current EVSE in the world, there are people using other high current EVSEs, and you are preventing all of them from charging at over 60A as well.

Please put a switch on the menu page to disable the 60A automatic charging limitation, I want my charging session done as quickly as possible to minmize charger losses. I paid for dual chargers, I don't have a HPWC, and there is no reason I need to be "protected from myself".

Interesting dilema, perhaps there is a problem charging over 60A right now. I read in other threads that there where ground faults or something happening with the HPWC over 60A because of possible voltage sagging. I didn't see anything confirmed.

I do have a question, what do you mean by "I want my charging session done as quickly as possible to minmize charger losses". The losses are generally a fixed percent, so it doesn't matter how fast or slow you charge. There might be a little difference on the high and low ends but this would be complicated to actually measure. Plus charging fast is going to potentially require more active cooling which is an additional waste of energy.

In you signature line you have OpenEVSE and you mentioned it. I just looked at that project and I find it interesting from an engineering point of view. I wrote something negative here but have edited my initial post. Looking at the parts guides and schematics for several revisions somehow I figured someone was using that crap Omron 30A relay in the 80A unit and the contactor in the photos looked like a fuse holder that I have in my scrap bin. So I assume you have seen the question and postings about others having charging problems trying to get to 80A. How do you know that the power doesn't drop out and cause the Tesla to reset?

A safety agency like UL or TUV would have a lot of fun testing one of those things. I bet I could get it to fail with a simple ESD or EMC test.

 

[mitch672]

If the charger is %85 efficient, the lower the on time is, the %15 loss is minimized. I'm generally charging from %50 SOC to %70 SOC, under those conditions, not much active cooling is used, if any.

Each OpenEVSE builder is responsible for the build quality and parts used on their build. I'm using a high quality 75A SquareD contactor, there is very little heat coming of that contactor, even during a 2-3 hour charging session, so the contacts are low resistance. The voltage shown on the Model S display during the charging session is also nearly identical to what's measured on the panel, so very little voltage drop as well. One issue I have is with my utility, the voltage collapse from 240-242 to 218-222 during a 75A load, they have measured the drop at the meter during a charging session, and they are in the process of installing another transformer closer to my drop. This has nothing to do with the issue of Tesla dropping the current from 75A to 60A, however... On 4.1 to 4.4, I've never had an issue (owned my Model S since 1/17/2013, been using the 75A OpenEVSE since day 1)
Power has never dropped out in the past, unless new firmware is causing an issue (doubtful), it's more likely Tesla is dropping the pilot signal and it reaquires, sees 75A, then drops it down to 60A, this is a different behavior than previous firmware releases.

Maybe you should look at my build before criticizing as well.
This is my build, I've built at least a half dozen OpenEVSEs to date, been involved with the project for several years, and have 30 years of electronics and electrical experience.
http://code.google.com/p/open-evse/wiki/75AOpenEVSE

 

[scaesare]

If the charger is %85 efficient, the lower the on time is, the %15 loss is minimized. I'm generally charging from %50 SOC to %70 SOC, under those conditions, not much active cooling is used, if any.

I'm with boilerbots in being unsure what you think you are gaining here. Perecentage of a total amount is not going to vary because of rate.

15% loss @ 75A over 1 hour: (240v * 75a * 1h) * .15 = 2700Wh

15% loss @ 15A over 5 hours: (240v * 15a * 5h) * .15 = 2700Wh



The same amount of power is delivered, and the same amount lost.

Now there are several reasons to want to charge at the maximum you can (including just because it's cool to watch your project hum along at full power :wink: ), bit minimizing efficiency losses isn't one of them.

Cool build, by the way.

 

[contaygious]

Anyone else have a bug where the media player resets to the pick your device screen all the time? E.g. When you get in the car or use the settings page? Really annoying.

 

[mitch672]

Anyone else have a bug where the media player resets to the pick your device screen all the time? E.g. When you get in the car or use the settings page? Really annoying.

Hey, if they document it, it's a "feature" . Yes I need to select my iPhone every time, 3 steps forward, 2 back...

 

[Dave EV]

One issue I have is with my utility, the voltage collapse from 240-242 to 218-222 during a 75A load

While I agree that Telsa should let you override the 60A limit if you want, I question the decision to continue to charge at 75A when your utility feed is clearly currently unsuitable for charging at 75A. If you are seeing a 20V drop at 75A that implies that there is appx 1500W of heat being generated somewhere along the line. Personally I would feel a lot more comfortable charging at 40A which probably isn't significantly less efficient at the car (look at Tom Saxton's testing with his Roadster a long time ago) but could be more efficient overall depending on how much the copper along the way is heating up. For sure I'm sure that your appliances and neighbors will appreciate not seeing the voltage drop 10% when you start charging the car. The NEC recommends that you design circuits so that you don't see more than 5% voltage drop - in this case I would cut your charge rate in half until the utility upgrades your service.