Is there a way to only charge to 80% full?

[CSW]

Anybody know of a way to have the level 1 portable charger that came with the Spark to stop charging at 80% full?
Or the level 2 charger? Or anybody rig something to do that? ............ I ask because I heard the Leaf actually has a setting to do that, as it is much better for the battery in the long run to charge to 80% rather than 100%. I would be fine with 80% for my commute so it would be fine for me to go 80% everyday so I figure could not hurt.

 

[Nashco]

Anybody know of a way to have the level 1 portable charger that came with the Spark to stop charging at 80% full?
Or the level 2 charger? Or anybody rig something to do that? ............ I ask because I heard the Leaf actually has a setting to do that, as it is much better for the battery in the long run to charge to 80% rather than 100%. I would be fine with 80% for my commute so it would be fine for me to go 80% everyday so I figure could not hurt.

Only way you can do it is to manually set a timer on your EVSE circuit (estimating when it will be less than fully charged), or program it to finish charging at a time that is slightly after you are actually leaving on a journey (ie. finish charging at 9 am, but you leave for work at 8 am).

The Leaf did have the 80% charge setting available for some, but not all years, as they chased a balance between battery warranty and labeled range. It's a long story, but the short version is that the test methods used for the official ratings as shown on the window sticker show a lesser range for cars that CAN charge to 80% compared to those that cannot. Strange, but true. Thank your government, not your vehicle manufacturer.

Bryce

 

[CSW]

Hm, using the car timer is a good way to go. Good info, thanks.

 

[cwerdna]

Anybody know of a way to have the level 1 portable EVSE that came with the Spark to stop charging at 80% full?
Or the level 2 EVSE? Or anybody rig something to do that? ............ I ask because I heard the Leaf actually has a setting to do that, as it is much better for the battery in the long run to charge to 80% rather than 100%. I would be fine with 80% for my commute so it would be fine for me to go 80% everyday so I figure could not hurt.

Fixed your post. For level 1 and 2 AC charging, the charger is on-board the car. See http://www.mynissanleaf.com/viewtopic.php?f=6&t=14728&p=332668#p332668.

You're talking about EVSEs. Unfortunately due to the way J1772 works (see https://code.google.com/p/open-evse/wiki/J1772Basics), the EVSE has no knowledge of the car's state of charge, so there's no way to do it there.

The Leaf did have the 80% charge setting available for some, but not all years, as they chased a balance between battery warranty and labeled range. It's a long story, but the short version is that the test methods used for the official ratings as shown on the window sticker show a lesser range for cars that CAN charge to 80% compared to those that cannot. Strange, but true. Thank your government, not your vehicle manufacturer.

Yep. '11 thru '13 Leaf had it. It only could be done thru charging timers on the '11 and '12. '13 could do it via that and a toggle. And yes, it's a long story. If one cares, see http://insideevs.com/2013-nissan-leaf-rated-at-75-miles-but-84-miles-using-the-old-system/ and http://insideevs.com/2014-nissan-leaf-mostly-unchanged-as-range-technically-moves-up-to-84-miles/.

It's a stupid test rule, and I wish it'd go away. Either the 80%/100% should apply to all vehicles or to nobody, instead of encouraging these stupid games like removing the 80% setting.

 

[SteveC5088]

Just so you know, Spark EV already has a battery management system that prevents charging the battery above a set level. I believe it is somewhere around 85% of full charge. There is a similar lower limit as well. Chevrolet does this to enable the battery to last much longer.

The battery thermal management system, which includes a water cooling system, is there for the same reason. Nissan did not do this for the Leaf, and Leaf batteries show a decline in capacity far sooner.

 

[Nashco]

If somebody liked to tinker, OnStar broadcasts SOC. One could ping OnStar once per hour or similar and if SOC is greater than X amount and plugged into a L1 or L2 EVSE, you could kill power to the EVSE or stop charging through the OnStar interface as well. It would take some fiddling with an additional web-interface at minimum (possibly a controller with internet access), but the pieces are there so that an individual could do this if they wanted to.

Bryce

 

[Zoomit]

SteveC,

So the battery rating (18.4 kWh) already incorporates a ~15% knockdown on both the top and bottom end to maintain battery health? That implies the battery is really sized to ~26.2 kWh but there's two 3.9 kWh buffers, at both full and empty, and the car is only able to use 18.4 kWh from the battery? (26.2 - 3.9x2 = 18.4)

This interests me because I typically use almost 90% of the stated battery capacity each day and I'm concerned/curious about how my high DOD per cycle will affect battery health. If your statement is true, I'll be much less concerned. What's the source?

 

[Jedi2155]

The Leaf did have the 80% charge setting available for some, but not all years, as they chased a balance between battery warranty and labeled range. It's a long story, but the short version is that the test methods used for the official ratings as shown on the window sticker show a lesser range for cars that CAN charge to 80% compared to those that cannot. Strange, but true. Thank your government, not your vehicle manufacturer.

Yep. '11 thru '13 Leaf had it. It only could be done thru charging timers on the '11 and '12. '13 could do it via that and a toggle. And yes, it's a long story. If one cares, see http://insideevs.com/2013-nissan-leaf-rated-at-75-miles-but-84-miles-using-the-old-system/ and http://insideevs.com/2014-nissan-leaf-mostly-unchanged-as-range-technically-moves-up-to-84-miles/.

It's a stupid test rule, and I wish it'd go away. Either the 80%/100% should apply to all vehicles or to nobody, instead of encouraging these stupid games like removing the 80% setting.

On the other end, the Government is trying to protect you from manufacturer tricks as well. What most people don't realize is that 100% may actually be 100% either. So the battery maker might say okay we'll increase the 100% rating and recommend users to charge to 80% most of the time. So now one manufacturer whose 100% rating might decrease the battery life from 2000 cycles to 500 cycles, versus another whose 100% rating is 1500 cycles.

This combined with the aspect that it is really hard for an end consumer to really understand how much capacity has degraded so the manufacturers can get away with it. There has to be some protection for the customer and allow the feature but present standards don't allow it easily and needs to be improved.

 

[SteveC5088]

SteveC,

So the battery rating (18.4 kWh) already incorporates a ~15% knockdown on both the top and bottom end to maintain battery health? That implies the battery is really sized to ~26.2 kWh but there's two 3.9 kWh buffers, at both full and empty, and the car is only able to use 18.4 kWh from the battery? (26.2 - 3.9x2 = 18.4)

This interests me because I typically use almost 90% of the stated battery capacity each day and I'm concerned/curious about how my high DOD per cycle will affect battery health. If your statement is true, I'll be much less concerned. What's the source?

Well, the Chevy Volt has a 16.5 kwh battery with 10.8 usable. I made the assumption that the Spark EV was similar, but apparently not with such a great buffer. This wikipedia article states it has a 21.3 kwh battery (not sure whether that is 2014 or 15). 18.4 is 86% of 21.3.

 

[Zoomit]

The rated battery size is 21.3 kWh for 2013-14 and 18.4 kWh for 2015-16 model years. All of that is usable, at least for my 2015. I've not seen any data that indicates there's an addition margin above that to allow for battery health or degradation and would welcome a source that says otherwise.

 

[elpwr]

http://gm-volt.com/wp-content/uploads/2013/08/Slide5.jpg

Claimed 81% DOD for the 2014 battery. There's your data. If full capacity was routinely usable, the battery life would be severely impacted.

 

[elpwr]

And here is a link to the entire battery article:

http://gm-volt.com/2013/08/02/spark-ev-versus-volt-battery/

 

[Zoomit]

Thanks for those links. It's apparent that when discussing anything associated with the Spark EV battery that model year must be considered. It is hard to find MY2015-16 battery information from GM (an example why I don't trust GM). Here's a summary:

Model year: 2013-14
Battery energy, rated: 21.4 kWh
Battery energy, usable: 17.3 kWh
DOD: 81%
Weight: 560 lb
Mfg: A123

Model year: 2015-16
Battery energy, rated: 18.4 kWh (from GM press release)
Battery energy, usable: 18.4 kWh (my speculation)
DOD: 100% (my speculation)
Weight: 474 lb
Mfg: LG Chem

This Inside EV article has a good discussion about the MY15-16 battery. It speculates that "the depth of discharge of the pack has been significantly increased" to be able to yield the same range as the original battery. Many sources site the lower weight as the reason why the car maintains the same range, but the 86 lb savings won't have that much affect on range.

My personal data tracking shows that the usable energy is very close to the rated capacity. Using onboard and app data, my average predicted usable energy is nearly 18.4 kWh and typically varies based on how hard the battery is used. I speculate that you can pull the full 18.4 kWh from the newer battery. Recently elpwr stated in another thread that he saw 18.7 kWh from his MY15 battery after using the full battery down to 3 miles. I don't know how that happens.

 

[Zoomit]

One other point, it appears the Gen2 Volt is using a very similar battery to the MY15-16 Spark EV. This slide from GM shows the Volt has a 18.4 kWh rated battery, of which only 14.0 kWh is usable; again this is for the MY16 Volt.

 

[CSW]

I think I am going to charge it to 100% each time and hope that Chevy has hade provisions to make sure the battery is protected....

 

[kevin]

Thanks for those links. It's apparent that when discussing anything associated with the Spark EV battery that model year must be considered. It is hard to find MY2015-16 battery information from GM (an example why I don't trust GM). Here's a summary:

Model year: 2013-14
Battery energy, rated: 21.4 kWh
Battery energy, usable: 17.3 kWh
DOD: 81%
Weight: 560 lb
Mfg: A123

Model year: 2015-16
Battery energy, rated: 18.4 kWh (from GM press release)
Battery energy, usable: 18.4 kWh (my speculation)
DOD: 100% (my speculation)
Weight: 474 lb
Mfg: LG Chem

This Inside EV article has a good discussion about the MY15-16 battery. It speculates that "the depth of discharge of the pack has been significantly increased" to be able to yield the same range as the original battery. Many sources site the lower weight as the reason why the car maintains the same range, but the 86 lb savings won't have that much affect on range.

My personal data tracking shows that the usable energy is very close to the rated capacity. Using onboard and app data, my average predicted usable energy is nearly 18.4 kWh and typically varies based on how hard the battery is used. I speculate that you can pull the full 18.4 kWh from the newer battery. Recently elpwr stated in another thread that he saw 18.7 kWh from his MY15 battery after using the full battery down to 3 miles. I don't know how that happens.

Interesting. By extrapolating the "% used" and "kWh Used" values from the energy display I plotted the usable energy on my 2014 Spark and it has been dropping since I bought it two years ago. It started at ~19.5kWh and is now ~17.3kWh which that information states is the expected value!!!

Kevin

 

[elpwr]

The 18.7 kwh I observed as used when down to 3 miles was in my MY 14 Spark. That doesn't square very well with the reported 17.3 kwh usable in the link I provided. Hard to know what is actually correct.

I would be very leery of using the full 100% capacity and expecting any reasonable battery life.

 

[elpwr]

Kevin's data showing about 11% degradation in two years is a little disappointing. If that continued in a linear fashion (a big "if") the capacity at the end if the 8 year warranty period would only be 56% of new.

 

[CSW]

I just can't think that Chevy expects people to stop charging at 80% all the time for max battery life!
Most normal people are not going to do that.... nor should they have to in my opinion.
I have had a 2014 Spark for about 1.5 years now and the battery shows ZERO degradation when going
by my available range showing.
I have about 22k miles on the car now.
I consistently get 90+ miles showing.
I only charge on a regular 110 outlet at 12amps mostly with an occasional level 1 supercharger stop.

As a side note, when would Chevy replace the battery under warranty ?
How much capacity would it need to loose?
I know the Leaf has a limit, I forget how much, but they do.

 

[Zoomit]

The 18.7 kwh I observed as used when down to 3 miles was in my MY 14 Spark. That doesn't square very well with the reported 17.3 kwh usable in the link I provided. Hard to know what is actually correct.

I would be very leery of using the full 100% capacity and expecting any reasonable battery life.

Ah, right--I forgot your "new" Spark was the deal on a '14.

Concerning battery life, I know of one way to avoid any concern of routine high battery usage. LEASE!