What's the total, and usable, battery capacity?

[DarrenDonovan]

I've seen different numbers, anywhere from 18 kWh to 21 kWh.
Thanks,

 

[Nashco]

It depends. The only thing that actually matters is usable, which varies with usage patterns, environment, etc. The most I've got with my '14 was 19.2 kWh. I've had as little as 18 kWh.

Also note that the '15 has less usable battery capacity than the '14.

Bryce

 

[DarrenDonovan]

Did you run your battery down to empty when you saw the 19.2 kWh? With the Volt, I could drive until the battery runs out, and see how much kWh was used. With a BEV, I don't want to chance running to empty just to see the final number.
Thanks,

 

[Nashco]

Yup, ran it out on purpose to see how it reacted. Pushed it 500 feet to the charging stations had hoped to make it to, all in the name of science!

Bryce

 

[DarrenDonovan]

Yup, ran it out on purpose to see how it reacted. Pushed it 500 feet to the charging stations had hoped to make it to, all in the name of science!

Bryce

That's just awesome! Thanks for your contribution to science. :mrgreen:

 

[agdodgerfan]

Anyone know how to tell if your battery has lost capacity? I'm almost at 30,000 miles.

 

[TonyWilliams]

The 2015 is about 19kWh usable, and the 2015 is about 18kWh usable.

One caution on battery capacity is that temperature is a big variable, as is degradation (increased internal resistance).

Virtually all batteries are rated at 20-25C (68F to 77F) degrees.

 

[agdodgerfan]

Sorry but that did not help. How can i tell if my capacity has degraded? Is there a light that will turn on? Or do i have to run it to zero to see how much energy i used?

 

[Nashco]

Sorry but that did not help. How can i tell if my capacity has degraded? Is there a light that will turn on? Or do i have to run it to zero to see how much energy i used?

Your battery is always deteriorating very slowly, even if you don't use it, just like we humans. The only way to track the usable battery capacity yourself is to run it full to empty in the same conditions and record how many kWh are used from full to empty. GM hasn't made any other mechanism available.

I guarantee your battery has reduced capacity after 30,000 miles. How much? No idea.

Bryce

 

[FutureFolly]

Sorry but that did not help. How can i tell if my capacity has degraded? Is there a light that will turn on? Or do i have to run it to zero to see how much energy i used?

In general, the degradation in EVs has been much better than previously expected.

Model S owners have been tracking capacity. It appears to be a fairly logarithmic pattern. 3-5% loss after 50,000 miles with a little less than double that being projected for 100,000 miles. The Spark will go through more charging cycles that will age the battery, but I wouldn't expect it to be twice as bad as a Model S.

 

[TonyWilliams]

My 2012 Tesla powered RAV4 EV has about 15% loss at 50,000 miles and 28 months. I have three other Tesla powered cars, but they are all too new to get viable data from.

 

[FutureFolly]

My 2012 Tesla powered RAV4 EV has about 15% loss at 50,000 miles and 28 months. I have three other Tesla powered cars, but they are all too new to get viable data from.

I would have expected more like a 10% loss at 50K miles. Model S charge loss data I've seen was around 5% loss at 50K miles. Do you know if this is typical of RAV4 EV owners?

 

[TonyWilliams]

My 2012 Tesla powered RAV4 EV has about 15% loss at 50,000 miles and 28 months. I have three other Tesla powered cars, but they are all too new to get viable data from.

I would have expected more like a 10% loss at 50K miles. Model S charge loss data I've seen was around 5% loss at 50K miles. Do you know if this is typical of RAV4 EV owners?

There are two fundamental differences between RAV4 EV and Model S:

1) RAV4 and Mercedes B-Class use 2900mah Panasonic cells, while Model S uses 3100-3400.

2) Model S has full time temperature control, while RAV4 is completely "dead" when turned off.

 

[agdodgerfan]

Thanks for the info. Since I drive almost 36k a year need to plan for a new battery before i finish paying off my car.

 

[TonyWilliams]

Thanks for the info. Since I drive almost 36k a year need to plan for a new battery before i finish paying off my car.

At 100,000 miles, your degradation in any lithium car battery will likely be at least 20%. In a Nissan LEAF, it could easily be 30-40%.

A new Nissan LEAF battery is about $6000. For a Chevy Spark EV, I suspect that it might be difficult to gat any new battery (merely because of the extreme limited production, and it's all built in Korea). But, there's no reason you can't get a battery from a wrecked car with far lower miles.

The smartest move for an extreme high mileage driver is to just get a new car more frequently, never allowing any car to get to the "new battery" phase. Or drive a car with more range than you need, so that you can keep driving it with 30-40% degradation.

 

[FutureFolly]

Thanks for the info. Since I drive almost 36k a year need to plan for a new battery before i finish paying off my car.

At 100,000 miles, your degradation in any lithium car battery will likely be at least 20%. In a Nissan LEAF, it could easily be 30-40%.

A new Nissan LEAF battery is about $6000. For a Chevy Spark EV, I suspect that it might be difficult to gat any new battery (merely because of the extreme limited production, and it's all built in Korea). But, there's no reason you can't get a battery from a wrecked car with far lower miles.

The smartest move for an extreme high mileage driver is to just get a new car more frequently, never allowing any car to get to the "new battery" phase. Or drive a car with more range than you need, so that you can keep driving it with 30-40% degradation.

It should be about as difficult as replacing a Volt battery pack. The 2015 Spark EV battery pack is built in the same facility as the Volt's battery pack with the same cells. The 2014 Spark EV battery pack was built by A123 with their iron-phosphate cells.

I suspect a battery pack rebuild will be the only realistic option for the Spark EV. Depending on when you need that it may be a very practical option. If you can get a new tax subsidy, you're much better off selling the car early and buying a new one. It may be the end of the decade before a rebuild is practical to consider.

 

[Nashco]

Thanks for the info. Since I drive almost 36k a year need to plan for a new battery before i finish paying off my car.

At 100,000 miles, your degradation in any lithium car battery will likely be at least 20%.

I think you're oversimplifying.

Reduced battery pack capacity isn't necessarily the same as reduced range (or reduced usable kWh). OEMs have the capability to adjust how users are able to use the battery throughout its life. If they're conservative, they're not going to give you the whole battery when it's new, and over time continue opening the usable SOC to keep range consistent throughout the life cycle. If they're aggressive, they'll let you use the whole battery and you're going to notice significantly reduced range over the life of the vehicle. And many shades of gray in between.

This is the secret sauce that no OEMs share openly, so it's really tough to decipher how cars will age over time when compounded with the variety of chemistries, battery management, thermal controls, etc.

Bryce

 

[TonyWilliams]

Thanks for the info. Since I drive almost 36k a year need to plan for a new battery before i finish paying off my car.

At 100,000 miles, your degradation in any lithium car battery will likely be at least 20%.

I think you're oversimplifying.

Reduced battery pack capacity isn't necessarily the same as reduced range (or reduced usable kWh). OEMs have the capability to adjust how users are able to use the battery throughout its life. If they're conservative, they're not going to give you the whole battery when it's new, and over time continue opening the usable SOC to keep range consistent throughout the life cycle. If they're aggressive, they'll let you use the whole battery and you're going to notice significantly reduced range over the life of the vehicle. And many shades of gray in between.

This is the secret sauce that no OEMs share openly, so it's really tough to decipher how cars will age over time when compounded with the variety of chemistries, battery management, thermal controls, etc.

Bryce

Perhaps it's oversimplified. I do not know of a single other manufacturer except GM who hides the battery degradation.

None of us know if the method used on the Volt is similar to the Spark.

 

[Nashco]

Perhaps it's oversimplified. I do not know of a single other manufacturer except GM who hides the battery degradation.

None of us know if the method used on the Volt is similar to the Spark.

How do I monitor battery degradation on a RAV4 EV? M-B B-Class? Fiat 500e? Energi? smart ED? Focus electric? Prius plug in?

There is no industry standard for this. In most cases, only hacking these cars can figure this out. In other cases, an OEM can even display "battery health" but with undistinguished units of degradation and has the ability to change what it means and displays through a simple software update.

The point is, nobody knows how YOUR battery is going to hold up for YOUR vehicle over time. We can only make rough approximations based on how that OEM's products have shown over time. For example, Volt batteries are doing pretty darn good compared to the industry. Will that carry into the Spark EV? Hard to say since the Volt has different chemistry and significantly different duty cycles, but we have seen that GM is pretty conservative in their estimates compared to real world experience. On the flip side, Nissan has been extremely aggressive in their estimates compared to real world experience. Only time will tell how that carries forward into the future.

We certainly shouldn't trust anybody saying that a Spark EV will have X% of reduced range at 100,000 miles, since the only people who could possibly estimate that are at GM or their battery suppliers, and they'll never say what that number will be (best case OR worst case). Some schmoe on the internet who doesn't have a Spark EV, a vehicle with the same batteries as a Spark EV, and doesn't work for a company that provides Spark EVs or their components definitely doesn't know before vehicles start hitting 100,000 miles in the real world. Maybe it's 5% reduced range, maybe it's 35% reduced range...???

At best, we can approximate usable kWh through the methods described earlier in this thread. By tracking it over time, we users will start to get an idea of how things are holding up. This is what EV drivers have been doing for quite some time, and probably will until there are industry standards on broadcasting battery health statistics as part of normal on board diagnostics requirements.

Bryce

 

[TonyWilliams]

Perhaps it's oversimplified. I do not know of a single other manufacturer except GM who hides the battery degradation.

None of us know if the method used on the Volt is similar to the Spark.

How do I monitor battery degradation on a RAV4 EV? M-B B-Class? Fiat 500e? Energi? smart ED? Focus electric? Prius plug in?

There is no industry standard for this. In most cases, only hacking these cars can figure this out. In other cases, an OEM can even display "battery health" but with undistinguished units of degradation and has the ability to change what it means and displays through a simple software update.

It seems you want me to defend the poor industry practice? I'm not likely to do that. But, to say that there is no industry standard for measuring battery capacity is most definitely not the case. Of course there is.

We (meaning EV enthusiasts) have the tools to get a pretty descent approximation of the "usable" range degradation, which is truly the only thing that the end user is concerned with. I'll list some of the range tests that I've done, which may help others determine their usable range over time, including some of the cars you listed (including the Spark EV... both 2014 and 2015).

http://insideevs.com/kia-soul-ev-range-autonomy-demonstration-nets-100-miles/

http://insideevs.com/all-the-results-from-the-largest-independent-test-of-nissan-leafs-with-lost-capacity-not-instrument-failure/

http://insideevs.com/real-world-test-2013-nissan-leaf-range-vs-2012-nissan-leaf-range/

http://insideevs.com/nissan-leaf-side-by-side-range-comparison-2012-vs-2013/

http://insideevs.com/real-world-test-shows-chevy-spark-ev-has-substainally-more-range-than-nissan-leaf-62-mph-wvideo/

The point is, nobody knows how YOUR battery is going to hold up for YOUR vehicle over time. We can only make rough approximations based on how that OEM's products have shown over time.

Precisely correct, and exactly what I offered.

For example, Volt batteries are doing pretty darn good compared to the industry.

We don't actually know how the Volt batteries are doing, which is particularly notable given your comments above. The only thing that we do know for sure is that GM:

1) Was uber cautious with the amount of capacity that was able to be used, and for VERY good reason. The chemistry that GM selected is precisely the same chemistry that Nissan used in the LEAF.

2) Very wisely made the Volt battery liquid cooled, while the LEAF has no cooling system whatsoever.

3) Used, in my opinion, a far better anode

That's it. Smart, logical choices.

Here's somebody who sounded the "Caution Alarm" about this chemistry battery long before either GM or Nissan delivered their first car, which will hopefully make it clear why the Volt does so much better in relation to the LEAF, in terms of degradation:

http://www.electricvehiclewiki.com/Battery_Capacity_Loss

Factors Affecting Battery Capacity Loss

Each Lithium ion battery chemistry has unique properties that affect the rate of capacity loss. According to Charles Whalen:

"... the Volt’s and Leaf’s respective battery packs have nearly identical chemistry, both using a lithium-manganese cathode. They both have the same sensitivity to high temps. Out of all the various lithium cathodic chemistries, lithium-manganese is the most heat sensitive and has the highest and fastest rate of capacity decay and degradation at higher temperatures."

The Leaf’s battery cell is manufactured by NEC, is a pouch type cell with stacked elements, a LiMn2O4 cathode from Nippon Denko, a graphite anode from Hitachi Chemicals, a Celgard PP dry separator, and an EC type LiPF6 electrolyte from Tomiyama.

The Volt’s battery cell is manufactured by LG Chem, is a pouch type cell with stacked elements, a LiMn2O4 cathode from Nikki Catalysis, a hard carbon anode (which is more robust and has better/longer calendar life properties than the graphite anode in the Leaf’s battery cell) from Kureha, a Celgard PP dry/SRS separator, and a PC type LiPF6 electrolyte produced in-house by LG Chem.

There are two sources of battery capacity loss, calendar losses and cycling losses. Calendar capacity loss is the loss from the passage of time while the battery is left at a set SOC, typically 60% in lab testing. Cycling loss is due to charging and discharging (cycling) the battery. It depends on both the maximum state of charge (SOC) and the depth of discharge (DOD), which is the percentage of the total capacity range that is used during a cycle.

Technically, lithium battery calendar life is a function of 4 variables:

1-Mean temperature
2-Standard deviation of temperature
3-Mean state of charge (SOC)
4-Standard deviation of SOC

Will that carry into the Spark EV? Hard to say since the Volt has different chemistry and significantly different duty cycles, but we have seen that GM is pretty conservative in their estimates compared to real world experience. On the flip side, Nissan has been extremely aggressive in their estimates compared to real world experience. Only time will tell how that carries forward into the future.

We don't need to wait for "time" to determine that Nissan screwed up. We knew that almost three years ago, when we conducted this test (which lead to a class action law suit, which lead to a "settlement" that got a battery capacity warranty):

Phoenix Range Test, Sept 15, 2012

We certainly shouldn't trust anybody saying that a Spark EV will have X% of reduced range at 100,000 miles, since the only people who could possibly estimate that are at GM or their battery suppliers, and they'll never say what that number will be (best case OR worst case).

Many times, this stuff is found on the internet. Heck, I have a full Panasonic spec sheet for the 290mah 18650 cells in my Toyota Rav4 EV's and Mercedes B-Class ED.

Some schmoe on the internet who doesn't have a Spark EV, a vehicle with the same batteries as a Spark EV, and doesn't work for a company that provides Spark EVs or their components definitely doesn't know before vehicles start hitting 100,000 miles in the real world. Maybe it's 5% reduced range, maybe it's 35% reduced range...???

You're absolutely correct. I don't know, you don't know, and neither does GM or the battery manufacturer... yet. That's how Nissan got caught with their pants down. Bad planning came first, but then I think a bit of "accelerated" durability testing obviously didn't correspond to what actually happened.

By the way, while this "schmoe" does not own a Spark EV, I doubt you could find a single GM engineer or battery supplier engineer who does either !!! Owning the car doesn't instill knowledge!

So, when you're pontificating whether 5% or 35% is more appropriate for 100,000 miles, I'll stick with my 20% guess.

At best, we can approximate usable kWh through the methods described earlier in this thread. By tracking it over time, we users will start to get an idea of how things are holding up. This is what EV drivers have been doing for quite some time, and probably will until there are industry standards on broadcasting battery health statistics as part of normal on board diagnostics requirements.

Well, virtually all of them currently have that battery health available... if you know where to look. Still, calculated data from the car's BMS doesn't really mean anything if the car won't "go the distance". So, nothing is going to replace actual range testing for the final word. Even Nissan would agree with me... now ;-)