JdeMO for the Roadster?

[Stefan T]

And i can see there is manny missing in sweden

 

[dpeilow]

And i can see there is manny missing in sweden

This is taking a feed from ChargeMap - a community driven map of charging points for electric vehicles so you can add them directly yourself there.

 

[tom66]

The concern I would have is if the Roadster battery is capable of being charged continuously at more than 16kW. For example, the cell balancing logic may not be able to balance enough current from each cell to prevent overcharging. Also, I am almost certain Tesla would void any battery warranty if this was used, as this would be operating the battery beyond design specifications. If the battery were not charged over the standard 90% charge then some concerns would be eliminated -- it would primarily be down to cooling. Charging a lithium-ion battery is less efficient than discharging one, so assuming 50kW charging is worse than say 50kW/80hp average power, how well will the cooling system be able to cope with the rate of charging?

 

[Stefan T]

This is taking a feed from ChargeMap - a community driven map of charging points for electric vehicles so you can add them directly yourself there.

I took a scren shot of upplanding.nu over southern sweden
The mark ups are for chademo chargers

 

[spaceballs]

The concern I would have is if the Roadster battery is capable of being charged continuously at more than 16kW.

I suggest you calculate C rate for each cell, likely will help answer your question.

For example, the cell balancing logic may not be able to balance enough current from each cell to prevent overcharging.

This make no sense, cell balancing only kicks in after charging is done.

Also, I am almost certain Tesla would void any battery warranty if this was used, as this would be operating the battery beyond design specifications.

I think If it fails it's the car manufacture job to prove that it caused the failure. Also worse case in my view is faster battery degradation which isn't covered by Tesla anyways.

If the battery were not charged over the standard 90% charge then some concerns would be eliminated -- it would primarily be down to cooling. Charging a lithium-ion battery is less efficient than discharging one, so assuming 50kW charging is worse than say 50kW/80hp average power, how well will the cooling system be able to cope with the rate of charging?

ESS will kick on cooling if it gets warm, I've done tests and I believe it it can cool the ESS fast for higher C charge rates. Also think about the discharge rates of the ESS on how fast it needs to cool the pack down if you were to take it on a race track....

 

[Stefan T]

one another ide accoring this topic is use CCS/EU insted of Chademo and replace the roadster contact with Type2 CCS/EU intlet
And in that case that posible to charge both AC and DC in same inlet

 

[tom66]

I suggest you calculate C rate for each cell, likely will help answer your question.

C rate for whole pack around ~1C at 50kW charging. Most li-ion cells are capable of this, but there are some cells that are less capable.

This make no sense, cell balancing only kicks in after charging is done.

I have worked with batteries that balance during the end stage of charging too. Presumably the existing controller can measure the cell voltages and end charging (or modulate power towards zero) as soon as any once cell hits, say, 4.2V. Will the new JdeMO controller do this? I do not know if the Roadster balances only when charge current is zero or if it balances throughout the cycle. I'm also not sure what the peak voltage they use is, I suspect it's much lower than 4.2V to increase cell lifetime.

I think If it fails it's the car manufacture job to prove that it caused the failure. Also worse case in my view is faster battery degradation which isn't covered by Tesla anyways.

Yes, most likely--but they would also immediately point to such a system in the case of any failure, such as the PEM, because they share the same battery bus. The owner would have to contest such a decision to refuse service. Lawyer up!

ESS will kick on cooling if it gets warm, I've done tests and I believe it it can cool the ESS fast for higher C charge rates. Also think about the discharge rates of the ESS on how fast it needs to cool the pack down if you were to take it on a race track....

Question is, can it do this without air flowing over the radiators? (I haven't looked into it but I'm presuming the Roadster has exposed radiators like the Model S for cooling while driving.) I know the Roadster has cooling fans but is the system purely designed to remove heat generated by 17kW charging? Would 50kW charging be possible given the lack of direct air flow?

There are a lot of unanswered questions about this project for me.

 

[Habious]

I think If it fails it's the car manufacture job to prove that it caused the failure. Also worse case in my view is faster battery degradation which isn't covered by Tesla anyways.

Yes...and no. Theoretically, it's up to the Manufacturer/"dealership"/Service Center to prove that the modification caused the failure. In practice, they can just tell you "We're not going to work on your car because you modified it."

Then what? You gonna sue them? If you can hire a better lawyer than theirs, you'll probably win the case. In the meantime, you'll have a really cool-looking lawn ornament. And, since it'll take 3 years to work through the court system, and the problem you're most-likely bringing the car in for service is the battery/charging, you're gonna have a dead battery pack at the end of the day.

I put in an aftermarket remote system in my Lexus once. Independently of that, I later had issues with the immobilizer system recognizing a valid key present (causing the car not to start sometimes). I took it to my Lexus dealership, and they said "There's too much going on in there that we don't know anything about - We're not going to touch it."

The aftermarket system I'd installed worked in parallel with the existing wiring, and "no wires were cut" during the install. None the less, Lexus would not touch the car.

I'm in no way saying "No one should do this!!!"; but I am saying that people need to be aware of the consequences. Especially considering that you can't take your car to "another dealership" for a second opinion, or take the car to an "independent service center".

I'm also not saying this WILL happen, but I am saying it COULD happen.

 

[spaceballs]

C rate for whole pack around ~1C at 50kW charging. Most li-ion cells are capable of this, but there are some cells that are less capable

Pack is 53kwh, so ~1C be at 53kw. You seem worried about this maybe you should find closest cells matching the roadster and run tests on it.

I have worked with batteries that balance during the end stage of charging too. Presumably the existing controller can measure the cell voltages and end charging (or modulate power towards zero) as soon as any once cell hits, say, 4.2V. Will the new JdeMO controller do this? I do not know if the Roadster balances only when charge current is zero or if it balances throughout the cycle. I'm also not sure what the peak voltage they use is, I suspect it's much lower than 4.2V to increase cell lifetime.

Switching from CC to CV is a good question, you should find out by asking the project owner for QA and post back here?

Question is, can it do this without air flowing over the radiators? (I haven't looked into it but I'm presuming the Roadster has exposed radiators like the Model S for cooling while driving.) I know the Roadster has cooling fans but is the system purely designed to remove heat generated by 17kW charging? Would 50kW charging be possible given the lack of direct air flow?

Do you own a roadster because if you did you should know the answer, the electric fans on the radiators have more than enough capacity. Also saying "I know the Roadster has cooling fans but is the system purely designed to remove heat generated by 17kW charging?" is just weird, think about how much is has to remove when you discharge at the maximum rate.

There are a lot of unanswered questions about this project for me.

How about seeing any of the modified Rav4 EV are having any of these issues? Or how about emailing the project owner for QA and post back here?

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Yes...and no. Theoretically, it's up to the Manufacturer/"dealership"/Service Center to prove that the modification caused the failure. In practice, they can just tell you "We're not going to work on your car because you modified it." ... I'm also not saying this WILL happen, but I am saying it COULD happen.

So your suggesting no significant car modification should ever be done to a car you own? And always roll over when Manufacturer/"dealership"/Service Center says tough?

 

[stopcrazypp]

Do you own a roadster because if you did you should know the answer, the electric fans on the radiators have more than enough capacity. Also saying "I know the Roadster has cooling fans but is the system purely designed to remove heat generated by 17kW charging?" is just weird, think about how much is has to remove when you discharge at the maximum rate.

I think his point was that when the car is stationary the air flow is completely different than from when you are discharging at maximum rate. You will not be anywhere near stationary when the discharging at maximum rate.

Radiator fans are typically not designed for a situation where the engine/motor is at maximum power but the car is stationary. For example, some cars overheat on a dyno when there is no external fan to provide air flow. While in this case, the car is not at maximum power, the difference is that it is at high power for a continuous amount of time (while a typical dyno run lasts an extremely short period in comparison).

 

[ElectricLove]

Has anyone modded a US Roadster PEM to accept 3ph input for charging?

Having been inside the PEM I can see what needs to happen but would really rather have a working sample to work off of... Perhaps a 3ph input Roadster owner would be willing to post some pictures of the inside of their PEM? It is my understanding (and I may be wrong) that the Euro-spec 3ph variant will allow something like 50% increased charging speed... I know it isn't DC quick charging but it would be an improvement...

 

[spaceballs]

I think his point was that when the car is stationary the air flow is completely different than from when you are discharging at maximum rate. You will not be anywhere near stationary when the discharging at maximum rate.

Radiator fans are typically not designed for a situation where the engine/motor is at maximum power but the car is stationary. For example, some cars overheat on a dyno when there is no external fan to provide air flow. While in this case, the car is not at maximum power, the difference is that it is at high power for a continuous amount of time (while a typical dyno run lasts an extremely short period in comparison).

Roadster has two of these in the 625 CFM 9" Spal Curved Blade Puller Fan 30100452 VA07-AP12/C-58A - Universal Parts Inc. | High Performance Automotive Cooling | Humboldt, IA
over the Radiator, they have plenty of CFM. Why don't you do the math to see how much heat would need to be generated at high charge rate? As if you know the IR of the battery, and charge rate.. you would know how much heat would need to be needed to be removed.

Also if this mod listens to the CAN bus it then would have the ability can back off C charge rate if ESS temp gets to high.. Also be able to see bricks voltages and taper from CC to CV without issues.

 

[dpeilow]

Has anyone modded a US Roadster PEM to accept 3ph input for charging?

Having been inside the PEM I can see what needs to happen but would really rather have a working sample to work off of... Perhaps a 3ph input Roadster owner would be willing to post some pictures of the inside of their PEM? It is my understanding (and I may be wrong) that the Euro-spec 3ph variant will allow something like 50% increased charging speed... I know it isn't DC quick charging but it would be an improvement...

There are no 3 phase input Roadsters. The EU ones are also single phase 70A.

 

[miimura]

Miimura made an insteresting remark. In the RAV4, the car must be on (with key) during the charge. Even if a good location can be found for the charge port, I can't see myself leaving the car with the key in there.

The RAV4 EV has the Toyota Smart Key System with push button start. You can take the key fob with you and lock the doors with the mechanical key, leaving the car in READY mode. However, if someone disconnected the charger and broke a window, they could drive off. To me, this is good enough for the kind of locations that host CHAdeMO chargers in California. I would mostly only be gone for a restroom break anyway. The hood also remains open about 8-10cm.

Edit: Also, if you do things like turn off the Daytime Running Lights and the NAV screen, it's not obvious that the car is on at all. The instrument panel is the only thing that would give it away. I think you can turn down the backlight on the instruments too.

Obviously, the CHAdeMO port placement on the Roadster will be very important.

 

[stopcrazypp]

Roadster has two of these in the 625 CFM 9" Spal Curved Blade Puller Fan 30100452 VA07-AP12/C-58A - Universal Parts Inc. | High Performance Automotive Cooling | Humboldt, IA
over the Radiator, they have plenty of CFM. Why don't you do the math to see how much heat would need to be generated at high charge rate? As if you know the IR of the battery, and charge rate.. you would know how much heat would need to be needed to be removed.

Also if this mod listens to the CAN bus it then would have the ability can back off C charge rate if ESS temp gets to high.. Also be able to see bricks voltages and taper from CC to CV without issues.

I can only do the cell part, not radiator airflow part (don't have the expertise). The cell I picked as closest is the Sanyo UR18650F (era is correct, Sanyo had confirmed contract with Tesla, capacity 2200-2400mah correct), DC internal resistance is 0.102 ohm. At 50kW and 410V charging voltage, current is 122A. 122A is split over 69 cells in parallel, so 1.77A per cell. That means 1.77A^2*0.102 ohm * 6831 cells = 2.18 kW of heat from cells alone (before module/pack level losses).
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100028067.pdf

At 16kW charging (ignoring AC-DC losses at the moment for simplicity and to be even more conservative), that goes down to 39A, or 0.565A per cell. That means 0.565A^2*0.102 ohm * 6831 cells = 0.222 kW, which is a huge difference.

For the Leaf, pack level charge resistance is 0.12 ohm. At 50kW and 403V charging voltage, that is 124A, so 124A^2*0.12 ohm = 1.85 kW of heat at pack level.
http://media3.ev-tv.me/DOEleaftest.pdf
Unfortunately I wasn't able to find cell resistance yet, which would be useful to estimate the pack level resistances and use it with the Roadster figures.

edit:
For the heck of it, I decided to do the CFM part as an estimate. The Roadster reaches peak power at ~40mph (3520 ft per minute). From the radiator fan being 9.72 inch * 9.72 inch and having two next to each other, the radiator is at least 2*9.72 inch * 9.72 inch =1.3122 sq ft in area. 3520ft*1.3122 sq ft = 4619 CFM from driving airflow. That compares to 625*2 = 1250 CFM with the fans alone.

 

[felixtb]

Has anyone modded a US Roadster PEM to accept 3ph input for charging?

Having been inside the PEM I can see what needs to happen but would really rather have a working sample to work off of... Perhaps a 3ph input Roadster owner would be willing to post some pictures of the inside of their PEM? It is my understanding (and I may be wrong) that the Euro-spec 3ph variant will allow something like 50% increased charging speed... I know it isn't DC quick charging but it would be an improvement...

As far as I know the EU roadsters are also single phase........?! were there some very last ones that were produced with 3ph....? I never heard of them at least.

- - - Updated - - -

ah dpeilow you got there before me.

 

[spaceballs]

.... 4619 CFM from driving airflow. That compares to 625*2 = 1250 CFM with the fans alone.

That more than enough to move 2kwh of heat, i.e. think of the size of your small portable AC space heater fan and how much heat it's moves.

... At 50kW ... = 2.18 kW of heat from cells alone ... At 16kW charging ... = 0.222 kW, which is a huge difference.

Good to see you crunching numbers!
~2kw is might be near the max capacity of the heat-pump in the roadster. But the nice thing about the large ESS thermal mass, even if you were at the limit of the heat-pump it would still be good enough. i.e. I've already did some ESS heat soak testing (your on that thread I see) with my roadster and shows even at 16kw charge with no active cooling on a >100F day, and ESS VDS temps stayed within nominal ranges. And when I enabled the ESS active cooling it cooled the ESS down fast.

All this is nonissue anyways if this mod can monitor the CAN bus and thus limit charge rates and temps.

 

[Oba]

... All this is nonissue anyways if this mod can monitor the CAN bus and thus limit charge rates and temps.

It's fun to pontificate about all the wrong ways to do this, but something has to control the CHAdeMO charger. That is one of two ways:

1) a reprogrammed Tesla firmware
2) an auxiliary external firmware

Either way would work, but I'm guessing whatever method is used, it just HAS to have AT LEAST the basic battery data, including voltages and temperatures that the car already knows. It's a bit silly to think that the battery would be allowed to overheat, as several seem to suggest.

Somenody asked up thread if there were any issues with the RAV4. It seems that if this equipment is already deployed on that car, if it either didn't work, or didn't work well, or caused some equipment issues, there would be people complaining. With an admittedly short search, I couldn't find anything like that.

There is a thread on the RAV4 forum that is two years old with over 50,000 hits.

 

[dpeilow]

Indeed RAV4 owners have posted that the mod works well in regular use.

 

[tom66]

Although the RAV4EV is based on a 2nd Gen (Model S-like) battery, powertrain and cooling system, which was designed with fast DC charge support at 90/120kW, where the Roadster isn't.

Remember the fiasco of 90 vs 120kW charging and how Tesla won't upgrade packs to support faster charging. Obviously they believe there are limits that aren't just down to cooling.

Does the Roadster use the AC compressor during charging like the Model S? When supercharging the Model S fans go full blast in hot weather.

I just have concerns that charging the battery at over 3x the original design rate may cause problems. Perhaps I'm being overly cautious, though.