Cobos

Thought I might mention that in the 35th comment on the latest Feel blog (Web2.0 vs Dead trees) in a comment made by Dirk the editor mentions that they will release more Whitestar info soon. Their definition of soon might not match mine, but I figure the Town Hall meeting on Thursday would be a good bet?

Cobos

Kardax

My stance on WhiteStar today is the same as before... Tesla should keep quiet about it until Roadster deliveries have started.

The reason: 600 people patiently (or otherwise) still waiting for their cars. Anything that makes Tesla look like it's distracted would make their paying customers very upset.

Tesla has nothing to gain by revealing WhiteStar details now.

-Ryan

malcolm

I'm not so sure.

As the recent DriveTrain shuffle proves - Elon is very smart and chooses to set tough technical challenges for the political benefits they bring. An announcement on Whitestar specs and styling ideas at this stage is going to be a copy of a presentation to possible auto partners and investors, not customers.

It is likely that it won't push envelops and preconceptions as the Roadster did since it is all about attracting an un-innovative but affluent auto partner.

But how on earth is Elon going to manage to stop himself from losing his patience with such a company?

vfx

An ambitious group are they? Not only are they building the Whitestar and the Bluestar but the Whitestar is to have TWO drivetrains!

All while tweeking the Roadster to work properly.

__________________
.
.
.
.
.
.
The world loves to be deceived.

Kardax

The Roadster is very nearly finished, it's mostly a matter of supply chain management now. This frees up the engineers to work on future projects.

-Ryan

malcolm

Thing that's puzzling me is how you recharge a battery pack while you continue to draw power from it, without affecting calender life and while maintaining reasonable performance.

Maybe you don't and just do what GM propose to do with the Volt - after the all-electric range is exhausted the generator kicks in but doesn't recharge the battery, simply stops it getting flatter.

TEG

It is all just power moving around. If you have a little tiny ICE generator running all the time you could draw 1/4 power from the generator and 3/4 power from the batteries. In other words the generator power could go right to the eMotor. You don't have to charge one side of the batteries and draw from the other.

The problem is the marketing angle of saying it is a "REEV". If you expect people to think of it as a 40 mile range EV with an "emergency range extender" never to be used except when you accidentally run the batteries down that is one thing. But I think in the real world you would prefer to have the ICE running sooner to keep the pack from getting all the way run down so frequently.
If you start up the ICE earlier and more frequently people may be more inclined to call it a hybrid instead of an EV with range extender. Marketing and engineering need to work together to work out all the details.

Kardax

I would think that running the pack down frequently is the whole point of any PHEV. Otherwise, why bother with the plug-in part?

-Ryan

TEG

Well, depending on how they engineer the thing you may have reduced performance when the battery pack is run down. For instance note how the Fisker plans to have a paddle on the steering wheel to switch from "Stealth" mode to "Sport" mode which will fire up the ICE to add some more power to get the eMotor up to full output (apparently the battery pack is inadequate by itself). If you have an ICE big enough to fully power the vehicle then you are carrying a lot of weight around.

If you are willing to fire up the ICE more frequently then you can consider some benefits:

#1: Battery pack doesn't have to offer as much max power output because you can supplement from the ICE/generator when requested.
#2: The ICE doesn't necessarily have to be as big because you run it while the batteries can help so you get a power blend for a longer range than you would get from the pack alone. Eventually the pack will still run down so you would end up in a low power "limp" mode if the ICE/generator was too small to keep the pack from getting fully discharged.
#3: You can drain the batteries more slowly if the ICE/generator is helping so you may be able to get through the month with less range of pack cycling which could help the batteries last longer in the long term.

Imagine you had a weight & price target, and you could take two approaches.

Approach #1:
40 mile battery pack + 70HP ICE generator
The vehicles runs on 100% battery until near empty then the ICE kicks in until you get to a plug. (Trying to be like an EV but with an emergency generator that maintains close to full performance on fuel alone when the pack is spent)

Approach #2:
80 mile battery pack + 20HP ICE generator
The vehicle starts up the ICE much sooner. You could go perhaps 250 miles on "blended power" (extended 80 mile pack + ICE assist) before you run the battery pack down and experience reduced performance (limping to a plug)

Approach #1 would be better if what you wanted was < 40 mile daily commute and never start the ICE. Also if you had a pack that could stand up to daily full discharge / recharge.

Approach #2 would be better if you routinely drove more than 40 miles but less than 250 miles before plugging in. You could do a fairly long commute without ever running the pack all the way down which would likely give the battery pack a longer lifespan.

I hope you can see what I mean - driving habits and plug-in habits could dictate different designs.

If you are willing to use "blended power" (ICE generator + some pack capacity) together then there are a lot more options as to how you size and configure things.

Kardax

I understand what you're saying, but I don't agree with some of your fundamentals...

Firstly, the only type of battery I can think of that has power output issues would be a small number of conventional lithium-ion cells. Get a large number of them (like in the Tesla Roadster), and you have all the power you need. There are also chemistries that trade energy density for power density... A123 and AltairNano (and likely others I'm not thinking of) can totally discharge in 10 minutes, then recharge in another 10, thousands of times without any substantial wear. Tesla has already indicated they're using a differenct chemistry for the PHEV version of WhiteStar, and my bet it's along the lines of the above...

Given that power output doesn't have to be a problem, your gas engine only needs to be big enough to sustain highway speed, plus a little extra to charge the battery. The battery would be used for bursts of energy when hard acceleration is needed. I don't think 20HP is enough, but 70HP is probably more than necessary.

If the engine is sized correctly, the only issue the customer would then need to consider is how much electric range they're willing to pay for. People who live close to work might go with 40 miles, longer distance people would go for 80.

The other thing is that battery lifespan isn't as important for PHEVs. If you get an 80 mile pack that's down to 60 after five years... you might not be affected at all. The worst case is that your engine will fire up sooner on a long trip, maybe costing you another $5 in gas.

-Ryan