I got to see and sit in a Bolt today

[oilerlord]

Michael, were you able to find out the total capacity of the battery? 60kWh is what is generally quoted, but is that usable or total capacity? If reviewers are easily getting 240 miles on a charge, then I'd assume 60kWh @ 4mpkWh to get there. The Volt 1.0 had a big buffer (something like using 11kWh out of 16), but I haven't been able to find those numbers for the Bolt. There are 200,000 mile Bolts on the road where owners report very little battery degradation.

I like that GM had the forward thinking in putting a battery conservation setting into the Bolt, but I wonder if limiting the range to 80 miles would merely mean more charge cycles, and wear out a certain part of the battery. Just thinking out loud...perhaps the Bolt's BMS automatically levels battery wear across all cells regardless of setting.

 

[Zoomit]

Michael, were you able to find out the total capacity of the battery? 60kWh is what is generally quoted, but is that usable or total capacity?

I don't expect to ever hear any more details from GM with respect to battery capacity. GM stated a few different numbers for the Spark EV, and no one has been able to definitively say what it's usable or total capacity is.

Based on what we've seen so far, 60kWh is a reasonable assumption for usable capacity and so the total could be 65-70 kWh.

 

[michael]

No, I didn't get that info. The people there were weak on those kind of details.

If INL tests the Bolt, they will determine and report the full capacity. For example, they reported that a brand-new Spark had 18.3 kWh, but after five months and 4000 miles it had dropped to 17.6 kWh

https://avt.inl.gov/sites/default/files/pdf/fsev/batterySpark4878.pdf

In general, manufacturers report minimum battery capacity when new (full charge to empty). :This gives them some room for sample variation. The usable capacity is less, of course. So If Chevy say 60, I would assume that is total, not usable. But that's my assumption only.

 

[michael]

Are you saying the "premier" trim doesn't have homelink? I could understand removing that option on the base car, but not on the high-end trim - especially on a $40,000+ car.

Homelink is also missing from the 2017 Volt and, I suspect, all or most other 2017 GM products. I have the impression it has also gone missing from some non-GM brands also. Maybe a licensing/pricing dispute?

You can get Homelink "guts" on Amazon and install it yourself. There was a post on another message board a while back showing how they were retrofitted to a new Volt.

The 2012 Focus had Homelink but it was omitted on later models. Lots of people bought the 2012 visor and installed it.

Yes, failure to offer Homelink as an option is silly.

 

[oilerlord]

This video implies 60kWh of total capacity (around the 17:50 mark):

https://www.youtube.com/watch?v=yQ8P7Ooo-7w

Generally speaking, EV's have a battery buffer around 20%, so the pack never entirely charges or discharges to extend the overall life of the battery pack. Has GM abandoned a battery buffer with the Bolt?

I think it's reasonable to assume 238 miles of "average" range is about right for a 60kWh battery - an efficiency of roughly 4 miles per kWh, a number on the high side, but reasonable. If GM had built a 20% buffer into the battery, that would leave only 48kWh usable. 238 miles on 48kWh - nearly 5 miles per kWh? I can't get there.

Since Volt 1.0, 1.1, 1.2, and 2.0, along with Spark 1.0 and 1.1, GM has cut into the battery buffer percentage. I think that aligns with customers valuing range above long-term longevity of the battery. As many will choose to lease, cycling deep into the 60kWh isn't relevant since they only have the car for 36 months.

An option on the B250e is a "range" mode that bumps the 28kWh usable to ~33 out of the total 36kWh. The Mercedes manual explicitly states only to use that mode on occasion as continued use may shorten the life of the battery. Michael, I think it explains why GM put a charge limit option to 40% in the Bolt - offering customers the ability to vastly extend battery longevity if they choose to do so.

 

[michael]

I did get confirmation from Chevy that the "hill top reserve" option provides 90% charging. So I would think that this option should be selected at all times except when maximum range is needed.

Between this and the 40% option, there are tools in place to preserve the battery.

 

[Zoomit]

The 40% option is not to save the battery. They don't like to be empty and being cycled around 50% is desireable.

 

[oilerlord]

When I was shopping for used B250e's, I was filtering out cars that had the extended range option - because I assumed that the guy leasing the car may have ordered it that way because they needed to use it all the time. Kudos to GM for putting that feature into the car, but I'd still only consider one with under 15,000 miles on it.

I originally intended to drive my car for 8 or more years, but my car plus ~$10,000 might get me into a used Bolt in 2018. We'll see.

 

[DucRider]

I think it's reasonable to assume 238 miles of "average" range is about right for a 60kWh battery - an efficiency of roughly 4 miles per kWh, a number on the high side, but reasonable. If GM had built a 20% buffer into the battery, that would leave only 48kWh usable. 238 miles on 48kWh - nearly 5 miles per kWh? I can't get there.

Since Volt 1.0, 1.1, 1.2, and 2.0, along with Spark 1.0 and 1.1, GM has cut into the battery buffer percentage. I think that aligns with customers valuing range above long-term longevity of the battery. As many will choose to lease, cycling deep into the 60kWh isn't relevant since they only have the car for 36 months.

~60 kWh is usable capacity. The journalists on the Monterey to Santa Barbara test route all used in the range of 58.x kWh to go the 240 miles.

We do know that the Bolt uses 288 LG prismatic cells in a 96s3p configuration. I think it very likely that the cells are the same 3.75 V 65 Ah ones used in the new 40 kWh Zoe. That would yield a 70.2 kWh pack or about 85% pack utilization. Some Li-Ion chemistries are better at preventing degradation. The Fit EV has virtually no known range loss, even with those that hit 50K+ in 3 years. There is no partial charge option, and most charge it to full every night (we do and have 29K with no range loss).
All we know about the Bolt battery chemistry is that it is "New" and developed specifically for the Bolt, plus it is "Nickel Rich" for better thermal performance. I cannot imagine longevity was not one of the characteristics they developed for. The Tesla/Mercedes battery and chemistry is relatively old (in the EV world) and much improvement has been made in the past 5 years. Only time will tell how well the Bolt battery performs in the real world.

 

[JeffN]

I did get confirmation from Chevy that the "hill top reserve" option provides 90% charging. So I would think that this option should be selected at all times except when maximum range is needed.

Between this and the 40% option, there are tools in place to preserve the battery.

Yup.

In addition, the Bolt EV has a “Hill Reserve” option that can be enabled to limit battery charging to the 90 percent level. As the name implies, this reserves some room in the battery when charging in the mountains or on hilltops so that regenerative braking can capture and store energy on the drive back down. In addition, Hill Reserve can also be used for regular daily charging for drivers wanting to avoid having the battery at a full charge for extended periods of time.

http://www.hybridcars.com/new-2017-chevy-bolt-ev-details-emerge-as-first-deliveries-approach/

 

[sam]

Spacious on the inside..great to know especially because it's not coming from a paid article but a real first hand review

 

[oilerlord]

~60 kWh is usable capacity. The journalists on the Monterey to Santa Barbara test route all used in the range of 58.x kWh to go the 240 miles.

We do know that the Bolt uses 288 LG prismatic cells in a 96s3p configuration. I think it very likely that the cells are the same 3.75 V 65 Ah ones used in the new 40 kWh Zoe. That would yield a 70.2 kWh pack or about 85% pack utilization. Some Li-Ion chemistries are better at preventing degradation. The Fit EV has virtually no known range loss, even with those that hit 50K+ in 3 years. There is no partial charge option, and most charge it to full every night (we do and have 29K with no range loss).

The Tesla/Mercedes battery and chemistry is relatively old (in the EV world) and much improvement has been made in the past 5 years. Only time will tell how well the Bolt battery performs in the real world.

I understand your hypothesis, though I haven't found anything out there that reports the Bolt's battery is actually 70kWh. Not sure why GM would want to keep that a secret.

There's no magic bullet in terms of lithium ion battery degradation, and no one manufacturer has eliminated it. Any improvements in the last 5 years have been at best, subtle but depend more on BMS keeping the battery at optimum temperature, and relying on battery buffers to help with long term durability.

Gary, your Fit EV's little 20kWh air-cooled Toshiba battery pack loses range too, if not only for the fact it will require a higher number of cycles to get to 50K miles than one in a "relatively old" technology 60kWh pack in a Tesla. Unless Honda figured out a way to cram a big battery buffer into your car, don't believe a couple of other posters on the Fit EV forum that feed into your confirmation bias. With only 1100 Fit EV's on the road, there isn't enough public feedback on the Internet to establish a baseline, and support your claim. The only way that you'll know for sure is to have the pack tested. I'd bet real money that your battery has degraded. Let's focus on science & fact, not magic.

 

[JeffN]

Gary, your Fit EV's little 20kWh air-cooled Toshiba battery pack loses range too, if not only for the fact it will require a higher number of cycles to get to 50K miles than one in a "relatively old" technology 60kWh pack in a Tesla. Unless Honda figured out a way to cram a big battery buffer into your car, don't believe a couple of other posters on the Fit EV forum that feed into your confirmation bias. With only 1100 Fit EV's on the road, there isn't enough public feedback on the Internet to establish a baseline, and support your claim. The only way that you'll know for sure is to have the pack tested. I'd bet real money that your battery has degraded. Let's focus on science & fact, not magic.

The Fit EV uses an unusual battery from Toshiba called the SCiB which uses a Lithium Titanate anode instead of graphite. The upside is that it can be charged much faster and degrades much slower from charge cycling. The downside is low energy density and I've heard maybe it doesn't do as well in cold temperatures.

 

[oilerlord]

The Fit EV uses an unusual battery from Toshiba called the SCiB which uses a Lithium Titanate anode instead of graphite. The upside is that it can be charged much faster and degrades much slower from charge cycling. The downside is low energy density and I've heard maybe it doesn't do as well in cold temperatures.

I read that too. Still, I'm skeptical of a claim of "virtually no" degradation after 50K miles without seeing any actual data from someone's Fit EV battery pack at 50K miles. A guess-o-meter along with a couple of guys making Internet posts doesn't do it for me.

 

[michael]

It would surprise me greatly if GM provided a 70 kWh total capacity battery but claimed only 60. I think it is the general practice in the industry to claim total capacity even if usable is less.

On the other hand, if you look at the INL test reports, you will see that in almost every case, the tested full capacity of a new battery exceeds the rating. So perhaps manufacturers reduce their claimed capacity to be sure that all cars, when new, at least achieve the rating.

 

[DucRider]

It would surprise me greatly if GM provided a 70 kWh total capacity battery but claimed only 60. I think it is the general practice in the industry to claim total capacity even if usable is less.

Some manufacturers report one number (useable or actual pack size) others report both.
With the Bolt, there is little doubt that 60 kWh is the usable number. The journalists testing the cars from Monterey to Santa Barbara all reported in the 58.x kWh used (with varying amounts - up to 50 miles - of range remaining). The only question is how much larger the pack is than 60 kWh since there has to be a lower and upper buffer.

 

[DucRider]

I read that too. Still, I'm skeptical of a claim of "virtually no" degradation after 50K miles without seeing any actual data from someone's Fit EV battery pack at 50K miles. A guess-o-meter along with a couple of guys making Internet posts doesn't do it for me.

The only thing you'll likely have available is anecdotal data. There is no way to access actual pack capacity by the end user, and it's unlikely Honda is going to release that info.
In my particular situation, I tracked miles driven and % of battery remaining (a numerical figure from the app/fob and not a guestimate from the "fuel gauge". I tracked it for about 3 months when new, and several 2-3 week samples in different seasons over the nearly 3 years we've had it.
Usable capacity is less in the winter (expected), and efficiency is also less (also expected). This Fall, useable capacity remained at about 18.5 kWh - the same as when new. The car is usually driven about 30-40 miles a day and topped off every evening. The range on the car is not noticeably different than when new (miles driven and remaining SOC - not from the guess-o-meter).
I had heard virtually no reports of range degradation on the sister site to this one (myhondafitev.com) so asked the specific question. The only negative response I got was "I think I lost a mile or two of range. But I got workplace charging a while ago and drive a bit more aggressively since then".
Take it for what it's worth, but people with negative experiences are often the most vocal, and I've yet to hear anything about range loss. Google "Fit EV range loss" and you'll find a fair amount about reduced winter range, but nothing about permanent battery degradation.

 

[oilerlord]

Not to get the thread too far on a tangent; the more I read about SCiB technology, the more I wonder why we aren't seeing it in mainstream EV's such as the Bolt, Leaf, and Tesla models. I've read 6,000 cycles to 90% of original capacity is theoretically possible. On a 200 mile EV - that 12 MILLION miles with only 10% degradation. Essentially, the motor would probably need replacing before the battery ever would. I've read that the downside is energy density, perhaps that's the reason...takes too much physical space to package 60kWh's of battery pack.

Your Honda dealership likely has the diagnostic equipment to test the battery, but would probably only do so if you made a complaint about range (which clearly, you have no reason to do). I requested a report on my battery's health as part of a condition of my offer to buy the car. At 6,000 miles, it stated 28.1kWh out of a possible 28.3.

 

[JeffN]

Not to get the thread too far on a tangent; the more I read about SCiB technology, the more I wonder why we aren't seeing it in mainstream EV's such as the Bolt, Leaf, and Tesla models. I've read 6,000 cycles to 90% of original capacity is theoretically possible. On a 200 mile EV - that 12 MILLION miles with only 10% degradation. Essentially, the motor would probably need replacing before the battery ever would. I've read that the downside is energy density, perhaps that's the reason...takes too much physical space to package 60kWh's of battery pack.

Yes, energy density and cost since if the cells are less dense you need a lot more or larger cells with more battery content to reach the same energy. And with a battery that large it would outlive the car and that's wasteful in some sense because new cars always need anew battery. If the Bolt's 238 mile battery degrades to near 80% after 1,000 full depth equivalent recharge cycles then that is nearly 200,000 miles and it is a closer match to the required longevity (of course, we don't know it's actual expected cycle degradation yet).

 

[JimmYK]

Great! I'll try to check one out myself!