Roadster 3.0

[ElectricLove]

Maybe I'm missing something but why are you saying Tesla "did that with the first ones"? They only charge the Roadster (existing cells) up to about 4.15v in range mode and discharge to something like 3.50v. That is not 100% of full capacity, although I don't think they can get any more from the bottom. Tesla rated the whole ESS at 56kWh and 53kWh usable.

Couple things,

1. 4.15V is a pretty high top point, there isn't much left in reserves for the battery at that point, maybe a few % capacity.

2. Like you said, not much left in bottom end either (best to stop them at 3.6V) and this is compounded by voltage sag during discharge because the voltages will dip below this threshold a few times in a cycle.

3. 56kwh rating is the rating of the cells, the cells are rated based on some "ideal" discharge profile, usually this is something like 0.2C for Lithium so that would be 28A continuous discharge (around 10kw), this rating would only be realized in practice if you drove at about 50 mph for 5 straight hours on a dyno, in real use it will most certainly have many peaks which exceed 0.2C and an average which also exceeds that value... What this means is that when the battery allows 53kwh out during a driving cycle it is "basically" allowing very close to 100% of the actual battery capacity (rated for that driving cycle)...

This obviously represents a major challenge for any/all EV manufacturers and the question becomes how to fix it... the simplest answer is larger buffers... the Roadster should have only been allowed 40kwh of its capacity... but then it would have been a 180 miles range car and not beat the magic 200 mark... and there isn't room for more batteries, unfortunately, so at the time the best was done with what was available...

The Model S is also subject to this challenge because Tesla is selling themselves on longer range, of course a 100kwh battery may actually perform closer to 100kwh because 0.2C would mean 20kw of power (appx 60 mph speed)...

I just think for long term durability it makes more sense to have 20% less range but a phenomenal longevity due to gentlest possible battery cycling. Chevy has done this in the Volt, will carry it through to Bolt, Toyota has done it in Prius (who else has several million cars with electric motors and battery packs on the road... no one)... not saying the Tesla isn't a better car, it is, but those engineering risks are errors made in young companies which we alpha/beta owners bear the burden for...

 

[Adrian Cockcroft]

Maybe you can take your Roadster to Refuel races again and see what effect (if any) the new pack has on your track times?

Did you run into performance limit modes on the track before? If so, were they ESS, motor or PEM related?

I found the motor overheated first, then the PEM. It was good for a time trial flying lap of Laguna Seca, but after a few laps power would reduce too much so I'd only get about 10 minutes of track time per session at a track day. It works better at autocross, but the brakes were too weak. Since then I've upgraded the brake discs and the front tires so I will probably autocross it again, but don't plan to take it to the track.

Latest from Tesla on the 3.0 battery upgrade is that I'm second in line at Palo Alto, they haven't changed the car yet (according to openvehicles data my CAC is still [email protected] miles). I think some local "celebrity" owners may be pulling rank and bumping my car down the list.

 

[bolosky]

I just think for long term durability it makes more sense to have 20% less range but a phenomenal longevity due to gentlest possible battery cycling. Chevy has done this in the Volt, will carry it through to Bolt, Toyota has done it in Prius (who else has several million cars with electric motors and battery packs on the road... no one)... not saying the Tesla isn't a better car, it is, but those engineering risks are errors made in young companies which we alpha/beta owners bear the burden for...

Except this isn't a hypothetical anymore, we now have many years' worth of data. Roadsters have in practice done much better than Tesla promised they would in terms of battery longevity. I suspect that this is in large part because people mostly didn't run the batteries down to very low charge very often, but you engineer for the real world not the worst case when you're building something like cars.

So in retrospect if I could go back and chop off 20% of the range in order to make the battery last longer, I'd be way behind, because after 100K+ miles and nearly 7 years I've only lost 12%-13% of the original capacity. That is, I've still got more range than your hypothetical new car would, and certainly way more than your version would after the smaller amount of battery degradation that it would have had.

Now perhaps your version would do better in the 15-20 year range, but it's not clear that the batteries will last that long even in the best of circumstances.

 

[ElectricLove]

Except this isn't a hypothetical anymore, we now have many years' worth of data. Roadsters have in practice done much better than Tesla promised they would in terms of battery longevity. I suspect that this is in large part because people mostly didn't run the batteries down to very low charge very often, but you engineer for the real world not the worst case when you're building something like cars.

So in retrospect if I could go back and chop off 20% of the range in order to make the battery last longer, I'd be way behind, because after 100K+ miles and nearly 7 years I've only lost 12%-13% of the original capacity. That is, I've still got more range than your hypothetical new car would, and certainly way more than your version would after the smaller amount of battery degradation that it would have had.

Now perhaps your version would do better in the 15-20 year range, but it's not clear that the batteries will last that long even in the best of circumstances.

Well, here is how it would work in my scenario; your range would be exactly the same now as it was brand new and your praise of TESLA and the EV technology would be even higher! Reason? the 12% raw battery capacity loss would be absorbed into the 20% buffer (ie. the buffer size diminishes over time until there is no buffer anymore)... assuming your loss were at same rate using my algorithm (which I think you would have less capacity lost but regardless) right now you would have the exact same functional range as when you bought the car but "behind the scenes" you would have only an 8% buffer capacity remaining...

This technique does a few things;
1. Protect batteries through time by avoiding abuse (us roadster drivers don't do long trips and cycle our batteries much, it isn't surprising our batteries are outperforming predictions).
2. Give the customer a huge ease of burden and take down barriers to entry; customer knows they will have the same functional capacity of their purchase 10 years later...
3. Protect TESLA from battery packs that degrade a little faster than others by the nature of them being an organic product; instead of a customer who experiences a 10% range loss in first 2 or 3 years getting upset they would actually have the exact same range and wouldn't know their capacity had reduced a bit (but TESLA would know and could use that data to help in design/improvements). This would reduce warranty claims overall.
4. Give TESLA the ability to do a temporary capacity unlock for vehicles who run out of juice (instead of sending a tow truck to pull that last 15 miles to the next charger)... Now we are talking about another special TESLA feature that separates them from the pack and makes them more appealing...

Of course, the expense is a 20% reduction across the board in range, that would be 40-50 miles reduced range on Model S... Would they still sell? I think so, and I think the above 4 features would lead to an even higher customer satisfaction (and reduced operating expenses for the company)...

If someone from TESLA reads this and thinks "wow, what a great idea", get in touch with me ;-)

 

[JRP3]

Of course, the expense is a 20% reduction across the board in range, that would be 40-50 miles reduced range on Model S...

So the S 60 would have been a 160 mile range car, (not much more than the failed 40kWh version), and the 85 would have been a 210 mile range car. The 60 wouldn't have been able to make the distance between most superchargers. Terrible idea. Tesla isn't seeing any significant range degradation in high mileage Model S's, so what you suggest is not only a bad idea it's completely unnecessary. Not to mention it would have made the Roadster a sub 200 mile range car. The 200+ mile range point was very significant for marketing, plus I think there are a number of Roadster owners who would disagree with your claim that they don't take long trips.

 

[ElectricLove]

So the S 60 would have been a 160 mile range car, (not much more than the failed 40kWh version), and the 85 would have been a 210 mile range car. The 60 wouldn't have been able to make the distance between most superchargers. Terrible idea. Tesla isn't seeing any significant range degradation in high mileage Model S's, so what you suggest is not only a bad idea it's completely unnecessary. Not to mention it would have made the Roadster a sub 200 mile range car. The 200+ mile range point was very significant for marketing, plus I think there are a number of Roadster owners who would disagree with your claim that they don't take long trips.

Perhaps the 60 wouldn't have existed? The 85 would be the only one that actually fulfilled the 200 miles minimum range need. Perhaps the Roadster would have had a slightly larger capacity battery to make it 200 as well (but recall that tesla thinks roadster is 245 miles range... So 20% is only a couple miles off 200, they wouldn't have needed much to get it back over 200. The "high mileage" Model S are still all only 3 or 4 years old, at the most and according to the PIA study 2012 and 2013 Model S have had an "uncomfortably" (to me) high number of in-warranty replacements done... Regardless, your pointing out results from a "short game", however people will want to see the numbers for 10 years old cars. If it is deemed that the vehicle is only 75% as functional at 10 years as it was new, what does that do to resale? Will people even want to buy used ones? The long term range degradation and battery swap price are definitely going to say something to the average consumer about the viability of a TESLA product. I think TESLA chose to go the route of "let's make the batteries cheaper so it won't be such a hard blow to consumers", they have reported absurd future battery prices which suggest they thought that would be the saving grace to the fear consumers have of the failure of this expensive component.

 

[jeremyz]

I have a friend who does lithium ion battery research. I was asking him about the Roadster battery chemistry. He said that the worst thing to do to a Lithium Cobalt Oxide battery is to deplete all of the lithium from the cathode (the cathode is the LCO). The cathode has layers of Cobalt and Oxygen that store Lithium between them. Depleting the lithium allows the layers of Cobalt and Oxide to collapse on top of each other. After they've collapsed, you can't stick Lithium back in between the layers and you lose capacity. As a side benefit, it can draw some of the Oxygen atoms out to react with Lithium, lighting your laptop on fire and making you a youtube celebrity. As the battery charges, the Lithium leaves the cathode, so having an overcharged battery is problematic. The collapsing of the layers is also exacerbated by heat. So, the worst state for the battery for capacity loss is being overcharged and hot.

It seems to me like Tesla babies the Roadster pack enough that the capacity loss is pretty reasonable.

 

[wycolo]

Near bricking situation:

Roadster 2.0 unplugged for approximately 49 days from a full Standard Charge. Visiting civilian then reports screen showing: '5' and also the word 'maintenance'. Car was then plugged in (Sept 26, 2015). As of March 7, 2016 the sheriff reports the car appears unmolested and still plugged in but he did not approach car. So it is unknown if battery was ever successfully brought back up to full charge.

I've never seen 'maintenance' before but presumably if battery slowly drains to below a certain threshold then the screen shows this word.

So 50 days in the summer might serve as a Bricking benchmark.
--

 

[gregd]

Near bricking situation:

Roadster 2.0 unplugged for approximately 49 days from a full Standard Charge. Visiting civilian then reports screen showing: '5' and also the word 'maintenance'. Car was then plugged in (Sept 26, 2015). As of March 7, 2016 the sheriff reports the car appears unmolested and still plugged in but he did not approach car. So it is unknown if battery was ever successfully brought back up to full charge.

I've never seen 'maintenance' before but presumably if battery slowly drains to below a certain threshold then the screen shows this word.

So 50 days in the summer might serve as a Bricking benchmark.
--

I believe simply leaving the car plugged in is not sufficient for long term battery maintenance. The car also needs to be put into storage mode. Otherwise it will charge once and stop, needing to be unplugged and re-plugged to charge again. (Am I remembering this right?)

 

[Stefan T]

If the car is pluged in to a HPWC it will start up every day and charge

 

[pharma5]

If the car is plugged into a regular wall outlet, it will also wake up approximately daily and trickle charge for a short period.

This will keep the car charged for its respective setting so long as there isn't: (i) loss of power to the outlet for a very extended period; (ii) ground fault circuit interrupt (gfci) trip on the outlet; (iii) gfci trip on the charging cable. The gfci trips become problematic if the car is unattended for a very long period (e.g., out of country on vacation) and no one is there to hit the "reset button" on the outlet or cable for you.

 

[wiztecy]

If the car is pluged in to a HPWC it will start up every day and charge

Only if you explicitly selected the option to charge at a specific time. If its set to the option where you the user pushes start to charge, it won't charge every day, only when the user initiates it is my understanding.

 

[BartJ]

Only if you explicitly selected the option to charge at a specific time. If its set to the option where you the user pushes start to charge, it won't charge every day, only when the user initiates it is my understanding.

IMO that's not correct- my 2.5 starts a charge every 24 hours - regardless to what source it is connected.

 

[ggr]

IMO that's not correct- my 2.5 starts a charge every 24 hours - regardless to what source it is connected.

My understanding too.

 

[TEG]

Roadster 3.0 for sale:
2011 Tesla Roadster Sport 3.0 for Sale

 

[JRP3]

Roadster 3.0 for sale:
2011 Tesla Roadster Sport 3.0 for Sale

The 3.0 battery pack boosts the range to 400-miles.

They might end up with an unhappy buyer if they don't correct that.

 

[Habious]

They might end up with an unhappy buyer if they don't correct that.

It also isn't the "first" and certainly not the "only" 3.0 Roadster out there.

 

[ecarfan]

Roadster 3.0 for sale:
2011 Tesla Roadster Sport 3.0 for Sale

Very nice Roadster. Unfortunately the ad text has multiple factual inaccuracies in it. They could be characterized as "Lies" since a quick Google search would show they are untrue.

I predict that the seller will never get anywhere close to the stated $125,988 asking price.

 

[hcsharp]

If I was looking for a Roadster I would give more than 100k for that one.

 

[strider]

IMO that's not correct- my 2.5 starts a charge every 24 hours - regardless to what source it is connected.

Is your car set to "charge on plug in" or do you have a time set to begin charging? If it's the latter (time set) then yes it iwll wake up every 24 hours and charge. Wiztecy is saying that if you have it set to "charge on plug-in" then it will only charge once. I have a timer set on mine so I can't confirm or deny his statement.