Poll on battery size.

[ckessel]

I think your cost estimates are off.

I told you they were fictional for the sake of the mathematics exercise. The fact they were fictional didn't really change the point that if you want a large battery, you're likely better off getting it now rather than later.

Someone that's done actual battery cost analysis: How Much Does a Tesla Model S Battery Pack Cost You? We do the Math

They put the 300 mile pack at 40-45k (consumer price, not Tesla price). To upgrade from 160 to 300 later down the line for 10k you'd have to see A) HUGE reductions in battery prices, which historically haven't seen dramatic drops, and B) really good trade in value on your old pack, which seems questionable given you're giving back a degraded old-technology battery.

 

[onlinespending]

I think he, (and certainly I), was thinking more along the lines of keeping the battery until it wears out enough that it no longer provided enough range, and then getting a new pack, which would take much longer than the 3 years you used in your calculations.

Exactly. By then the price of a 300 mile range pack (or perhaps even greater capacity) will be significantly less that upgrading to a 300 mile pack versus simply replacing it with another 160 mile pack will be a far easier decision.

And not that I think this will happen, but by getting the lower capacity battery and not paying that extra $20k upfront, I minimize my exposure to something bad happening. What if Tesla fails as a company? What if the Model S is riddled with reliability issues? I'll feel far better knowing that I didn't sink another 40% into the car. The 160 mile option covers 99% of my trips and allows me to enjoy the car with the least upfront cost. If all goes well, costs come down, then perhaps I'd consider the 300 mile option down the road.

 

[dsm363]

If the 160 mile pack meets your needs, go for it. Others want or need more range. I'm looking forward to the 300 mile pack even though it won't be used every day.

 

[WhiteKnight]

I thought 160 miles but then I read that the batteries drop to 70% capacity in 7-10 years. Also if you like to really accelerate or you're driving at highway speeds (85mph here in ATL) then you're not getting 160 miles you're getting something less. If you look at Tesla's Roadster spreadsheet (I know it's apple to oranges but it's all we've got) it's 55kwh battery has a range of 243 miles at 54 mph but if you crank it up to 76 mph the range drops by 33% to 163 miles. And then you figure you want to have some juice in reserve for a trip, plus they don't want you pulling below 10% on a regular basis (or topping off above 90% - I think). So now it seems like the only option for me is 300 mile pack (maybe squeak by with 230 miles) since 300 x 70% x 67% x 80% = 113 miles. And I haven't even trid to factor in having the car full of my big fat relatives.

For what it's worth . . .

Here is my earlier argument for why you want to go with the 300 mile battery pack.

Also I talked to a Tesla representative who said that warranties are not final but most likely the 300 mile pack will carry a longer warranty because you don't have to use as deep a discharge for the same amount of driving. If you're doing 50 miles per day then you're using 32% of the 160 mile pack but only 16% of the 300 mile pack. So the 300 mile pack will last longer with the same amount of driving.

 

[onlinespending]

I told you they were fictional for the sake of the mathematics exercise. The fact they were fictional didn't really change the point that if you want a large battery, you're likely better off getting it now rather than later.

Someone that's done actual battery cost analysis: How Much Does a Tesla Model S Battery Pack Cost You? We do the Math

They put the 300 mile pack at 40-45k (consumer price, not Tesla price). To upgrade from 160 to 300 later down the line for 10k you'd have to see A) HUGE reductions in battery prices, which historically haven't seen dramatic drops, and B) really good trade in value on your old pack, which seems questionable given you're giving back a degraded old-technology battery.

Yeah, maybe not in 4 years time....but I'd guess certainly within 7 years. I think this is a fun exercise though...to hypothesize how this may all play out :smile:

Does anyone know if the 160 mile pack simply uses less Li-ion cells than the 300 mile pack, or does it use the same number of cells but each of a lesser capacity? If it's the former, and there's essentially empty space in the battery pack structure for more cells, you could conceivably populate the space with higher density cells down the road while keeping the original, slightly degraded cells to increase your overall range. This could result in a cheaper upgrade path versus having to replace every single cell with new ones.

 

[WhiteKnight]

Does anyone know if the 160 mile pack simply uses less Li-ion cells than the 300 mile pack, or does it use the same number of cells but each of a lesser capacity?

I remember hearing/reading that the 230 mile pack uses more cells than the 160 mile pack but that the 300 mile pack uses more advanced chemistry (higher density cells) than the 230 mile pack.

The home run would be if ultracapacitor technology advances to the point where you can get a pack of ultracapacitors with the same mileage. Then you could quick charge in less time than it would take to fill your gas tank.

 

[NigelM]

At the station showing the battery tray, I did ask if the smaller battery pack was using the same cells and was told "yes, we just will have a different layout in the tray".

 

[ckessel]

If it's the former, and there's essentially empty space in the battery pack structure for more cells, you could conceivably populate the space with higher density cells down the road while keeping the original, slightly degraded cells to increase your overall range. This could result in a cheaper upgrade path versus having to replace every single cell with new ones.

The packs are complete units. I don't think they'd ever mix and match them in that kind of refit. Presumably they'll give you a trade-in value and swap it out for a new pack.

 

[JRP3]

Does anyone know if the 160 mile pack simply uses less Li-ion cells than the 300 mile pack, or does it use the same number of cells but each of a lesser capacity? If it's the former, and there's essentially empty space in the battery pack structure for more cells, you could conceivably populate the space with higher density cells down the road while keeping the original, slightly degraded cells to increase your overall range. This could result in a cheaper upgrade path versus having to replace every single cell with new ones.

That would be a bit of a battery management nightmare.

 

[richkae]

I talked to the "Vehicle Range & Efficiency Architect". He told me some interesting things about the cells.

The cells they are going to use have different chemistry from the roadster.
The cells they are choosing from have a higher/wider "optimal temperature" range for longevity and performance than the cells in the roadster - that means they need to use less energy to cool the cells than the roadster needs.
The cells they are going to use have a lower self discharge rate than the ones in the roadster, so you can safely leave the car sitting not plugged in for longer than you can leave a roadster.

 

[Doug_G]

Ok, but what if you forget? Heck, some nights I don't even plug in my cell phone, but it's cool because it's got hefty battery life and I've got a desk charger at the office.

It rapidly becomes part of your routine. Yeah, in the last 15 months of ownership I've forgotten twice; got distracted or something. Wasn't an issue because I don't have to charge every night.

What if I stay at a friends house?

It would only be a problem if your friend lives 200 miles away. And I think if he was that far you would have made arrangements for charging.

What if I lose power?

Most blackouts last a few hours at most. Big deal.

When we had the huge Northeast blackout in 2003, my car just happened to be on fumes already and I couldn't buy gasoline because the gas stations had no power. Send my Tesla back in time, and that day I would have had over 200 miles range available when the blackout hit, because I plug in every night. I would have been in better shape.

A lot of what ifs true, but I'm huge on being independent (funny for a guy that's married), and get really uneasy if I feel as if I'm on a short leash.

In any case, it'll vary for everyone, but suffice to say if the 160 pack were the only option, I might not even be considering an s.

Well, there is a certain range below which I would not be comfortable if it was my only car, given the current state of charging infrastructure here (there isn't any). I can say that 240 miles is plenty. I use 15% to 25% most days, 50% once in a while, and barring the occasional longer road trip, I've never come anywhere close to 90%.

 

[JRP3]

I talked to the "Vehicle Range & Efficiency Architect". He told me some interesting things about the cells.

The cells they are going to use have different chemistry from the roadster.

Yes I think they added Ni to the mix, and have a higher energy density. I think 3.2ah as opposed to the Roadsters 2.4ah

The cells they are choosing from have a higher/wider "optimal temperature" range for longevity and performance than the cells in the roadster - that means they need to use less energy to cool the cells than the roadster needs.
The cells they are going to use have a lower self discharge rate than the ones in the roadster, so you can safely leave the car sitting not plugged in for longer than you can leave a roadster.

This is good since that helps improve the charge efficiency which seemed rather poor on the Roadster, especially in warmer conditions.

 

[jkirkebo]

Though AnOutsider bringing this up I did have a question. How many of you have your chargers in a EVSE (correct acronym, right?) in a garage vs. outside? I ask because at my parents house, if I were to get an EV, I wouldn't be able to put the EVSE inside the garage (we don't use it for cars, like most people in my neighborhood). I would have to put the EVSE outside, so I'm wondering how that would chance the "convenience" factor of it? For instance (I'm in Northern NJ so it does get cold, though admittedly not as bad as Canada or other places more north). I'm also wondering about charging when it's raining or snowing. That could make it nicer to have the larger battery so that if you need to wait out the weather a few days to charge, you have enough range.

My LCS-25 EVSE for our Leaf is mounted outside. I see no problems with this, and I live in Norway which gets it's fair share of rain, snow and cold weather...

 

[vfx]

Yep, wrong mentality. It takes me 10 seconds to plug it in. Big deal. I'd far rather do that in my garage daily than freeze my butt gassing up my car even once! (Picture 5 minutes holding a cold spigot with wind howling around you at -30C).....

I LOVE this image!

 

[vfx]

Two more (very different) reasons to buy a 300 mile battery pack.

The additional cost means nothing to you.

And

What is one of the first three questions you get about your Roadster?
To answer "300 miles" is opening their eyes that the future is here.

 

[JRP3]

Some eyes might close again when they hear the price. :wink: But you can always come back with the fact that in 3 years time Tesla went from selling a $120K Roadster with 240 miles of range to selling an $80K sedan with 300 miles of range. If that progression continues then in another 3 years they'll sell a vehicle for $50K with 400 miles of range, or drop the price even further for less range, since 400 miles seems excessive, especially as the charge network expands.

 

[Mycroft]

IMO, the most Joe and Jane Public would think to spend on the most luxurious car would be about $40k. Most buy used cars for $20k or less. So I think Tesla's goal of between 30 and 40 is a good one.

 

[shark2k]

My LCS-25 EVSE for our Leaf is mounted outside. I see no problems with this, and I live in Norway which gets it's fair share of rain, snow and cold weather...

Thanks for the response. Appreciate it.

-Shark2k

 

[Doug_G]

I LOVE this image!

You're welcome to it. Any time. You can have this one, too:

Yes, that really is my snow blower pretending to be a submarine, while people walk by on the trail above the top of the machine (it's not a fake perspective, they really are walking above the top of the machine). The winter of 2008 was insane.

Sorry for the off-topic diversion... back to battery packs!

 

[vfx]

I'm imaging another commercial where ICE drivers are in all sorts of miserable places filling up when our soccer mom unplugs while safe and warm in her garage.

Being in sunny CA I never thought of it before.


and OT

Buying a 300 mile pack means more cells sold means more demand = more development to better batteries.