ElectricMotorcycleForum.com
General Category => General Discussion => Topic started by: BrianTRice@gmail.com on December 18, 2019, 12:34:38 AM
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This is a remarkably well-presented study of several thousand EVs over time, with some charts.
Here are their summary recommendations, which align with what I've been hearing over the years from various manufacturers and engineers:
- Avoid keeping your car sitting with a full or empty charge. Ideally, keep your SOC between 20-80% particularly when leaving it for longer periods, and only charge it fully for long distance trips.
- Minimize fast charging (DCFC). Some high-use duty cycles will need a faster charge, but if your vehicle sits overnight, level 2 should be sufficient for the majority of your charging needs.
- Climate is out of an operator’s control, but do what you can to avoid extreme hot temperatures, such as choosing shade when parked on hot days.
- High-use is not a concern, so fleets shouldn’t hesitate to put them to work. An EV isn’t useful sitting idle in the fleet yard, and putting on more miles per vehicle is overall a better fleet management practice.
Links:- Article: https://cleantechnica.com/2019/12/16/new-data-shows-heat-fast-charging-responsible-for-more-battery-degradation-than-age-or-mileage/
- Original study write-up: https://www.geotab.com/blog/ev-battery-health/
- Charting tool for various vehicle model-years: https://storage.googleapis.com/geotab-sandbox/ev-battery-degradation/index.html
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I wonder how the minimize using DCFC applies to Tesla's that frequently charge through the supercharger.
Another point is where its stated that the nominal capacity being much lower than the actual capacity is a good thing. This certainly makes sense without having to add too much stress to the battery especially when its passively cooled. Adding some sort of an active cooling to the pack can certainly make a big difference to the Zeros.
I wonder what a low hanging fruit can be for Zero, in terms of having some form of active cooling to the pack.
-Shayan
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I will be a good test case for leaving the battery pack fully charged all of the time. So far I have owned my 2018 Zero for just over two years and there has been no apparent degradation of my pack since my bike was new. :)
Those recommendations might be for owners of EVs who want to keep their vehicles for many years. That is not me. ;)
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The problems with these recommendations is that every vehicle has a different battery configuration.
Some are passive or air cooled, so fast charging is a problem.
Some have more or less 'reserve' capacity or different nominal capacity and hence are bothered by running to 0 or holding at 100.
And some have more use-it-or-lose it chemistry, like the pre-2014 Zero batteries.
Still, they're fairly common sense suggestions.
-Crissa
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I bought my new Zero FXS 2020 a month ago and it sits in my garage here in Ohio for the Winter. Because of that same weather, I will end up riding it rather infrequently compared to those in California, but still as much as I can. I will probably not get my money's worth from the battery, and I knew that when I bought it. I'm okay with that.
My biggest fear is degradation as it sits. Anything I can do to minimize battery aging is paramount. Right now it's at about 59% SoC. When I do ride it, I'll do my best to keep it between 20-80% unless I need that extra push. High-speed charging will never be an issue since the onboard charger charges at .1C compared to the capacity.
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"GeoTab found that the the two biggest factors affecting the life of EV batteries are battery cooling and frequent high power DC charging. Age and number of miles driven are far less important to how long a battery lasts."
That corresponds well with the 5 year warranty with unlimitied miles Zero gives for their ZF14.4 Power Packs, while Zero warns from losing the warranty if one doesn't adhere to the Zero-charging-recommendtations which pretty much reflect the recommendations discussed in this thread.
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I still would like to hear from someone who has experienced noticeable battery degradation of their Zero battery pack - that wasn't the result of the stock on-board charger going south or that wasn't caused by actual battery failure.
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And for a bike that sat around: I took possession of my bike and at ~600 miles and 5 years old ....with no real detectable degradation.
Basically there doesn't seem to be any real worry about the batteries from 2014 and on.
-Crissa
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Basically there doesn't seem to be any real worry about the batteries from 2014 and on.
I couldn't agree more. People get all worked up over maximizing their battery life, but there just isn't any need to. I'm just short of 50,000 miles on my 2014 SR, I keep it plugged in all the time when it's at home, and I don't have the slightest sign of battery degradation. It's a total non-issue.
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Basically there doesn't seem to be any real worry about the batteries from 2014 and on.
I couldn't agree more. People get all worked up over maximizing their battery life, but there just isn't any need to. I'm just short of 50,000 miles on my 2014 SR, I keep it plugged in all the time when it's at home, and I don't have the slightest sign of battery degradation. It's a total non-issue.
I agree. But I bet it was some kind of an issue in the Farsis lab. ;) Personally, I think Zero could get away with a 10-year warranty on their battery packs. :)
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I just visited my daughter today and checked how her 2014 Zero S with PT was doing after having the new factory charger installed for the past 6 months. The bike's charger had been plugged in for the past day. Her battery pack is doing better than mine. It was showing 117 volts @ 100% SOC and battery balancing was alternating between 1 and 2 mV. My 2018 S typically shows 116 V @ 100% SOC, with balancing alternating between 3 and 4 mV when fully charged. Her bike has 16,300 miles on the clock. My bike only has 6,500 miles.
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Just because people haven't noticed battery degradation in ~ 5 years doesn't mean it isn't happening. In 10 years you should.
Farasis did not change the laws of lithium technology. Age is not a friend.
Let's not forget this post: https://electricmotorcycleforum.com/boards/index.php?topic=5314.0 (https://electricmotorcycleforum.com/boards/index.php?topic=5314.0)
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Someone was asking about battery degradation within five years. We have an answer.
Yes, lithium batteries work until they fall off a cliff. At some point in the next five years, we'll see that begin to happen. But the point was, one can get a good number of miles out of the current packs to be price-competitive with the ongoing maintenance cost of an ICE vehicle.
-Crissa
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I am told by a leading battery expert with in-depth knowledge of Zero's that my battery is showing signs of increasing impedance. Apparently impedance can increase in (at least) 2 ways? I bought a never-before-titled 2016 SR in 2018 (so batt warranty until 2023). While I have full range, my battery heats more than expected. So while the impedance is not affecting my capacity, it is said to be affecting temperature. It takes very short bouts of spirited riding or charging at <=0.6C [for less than 1.4 hours] to overheat my battery past 124F (opening contactor) on a cool ambient day with shade and wind. I'm told this is likely grounds for replacement but I think I will reevaluate this Summer to see how it does on a few 200-600 mile trips. I only have 10,000 miles. Even the stock charger could overheat my battery occasionally, but perhaps for different primary causes.
I almost always store at 40-60% and purchased the bike with extremely low miles on it.
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I'm told this is likely grounds for replacement but I think I will reevaluate this Summer
Does that condition qualify for a warranty replacement? If so, why wouldn't you just get it replaced?
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Because the capacity hasn't decreased. I'm trying to figure out how to reword my post. For riding, it is really only when riding quite spirited or on the highway for a while that I've gotten it warm enough to know that I couldn't charge "fast" (in less than 3 hours AKA >0.3C) later on. For charging, 0.6C frequently overheats it (where it stops charging for 30 minutes) even starting with a battery at ambient or lower. So my problem is heavily coupled with intent to charge faster than stock, which isn't a guarantee on these motorcycles. I've heard others on road trips can fast charge at a higher rate, multiple times, on warmer days than I've experienced even once without overheating.
I don't have the strongest case to stand on. Not being able to charge faster than Zero offers provisions for in-house isn't really a problem for them. My battery heating more quickly while riding (but not opening the contactor) is only an issue for me because *I* want to charge quicker. I might be out of options until it starts overheating at lower rates of charge/discharge, if that is possible.
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Zero supports their external chargers though, depending on the particular year and capacity that can end up charging close to 1C (the shortest specced charge time with current models is 1.6 hours to 100% so something like 0.6C, however a 6kW charge tank on a 7.2kW/h model at 6.3kW/h nominal is 0.95C).
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I put up a thread about a study, and it gets hijacked to discuss an individual bike.
Please don’t do this. Make a separate thread, at least so it’s easier to find discussions here, or link to them for the unofficial manual.
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I still would like to hear from someone who has experienced noticeable battery degradation of their Zero battery pack - that wasn't the result of the stock on-board charger going south or that wasn't caused by actual battery failure.
I am not sure if I should call this a fast degradation or a failure. But here are the facts with my Zero DS zf 6.5.
My Zero DS, will be in the shop fairly soon for a battery warranty repair. My range is around 50% of what it should be, if I can trust the SOC, as I never ran it to nothing. I will check the battery voltages soon at 50% discharge and other SOCs and then I will know more.
I just used up 48% of my SOC in a rather slow 12 miles.
Right now, I am checking the charge times. I started at 52% when the display says I have 2 hours and 9 minutes to go to full, using only the OBC. I started charging at exactly 1200 hrs noon. Right now, it says it has 40 minutes left to full charge and it's only 1224 hrs. So in less than a half hour, it charged more than twice as fast as it said it should to start with.
I have been looking on the web to see if I can find if it's the norm for battery degradation to also charge like a much smaller battery. I found a lot of info. just about everything except for what I am looking for.
Here is some more info on EV battery degradation. (https://batteryuniversity.com/learn/article/bu_1003a_battery_aging_in_an_electric_vehicle_ev)
Now the time is 1230 hrs and I have 34 minutes left to get to 100%, it says.
I am going to wait to full charge before I post this. I will use this time to change the brake pads in my SR that you told me about.
Now my DS is fully charged time is 1308 hrs. 1200 to 1310 hrs. One hour and 10 minutes for my two hour and 9 minute charge. Close to 50% less charge time, much like my range has decreased on my 6.5 KWH battery.
I need this bike to pick up my RV that is in the shop. RV broke down (bad fuel pump in a 55 gallon gas tank) on New Year's Day, 135 miles from here. Had to be towed back. The shop I now have my RV in is 11.5 miles from here. Slow on the freeway, I will barely make it. Then I put the DS on the RV ramp, change vehicles when I get back here, and the take the DS to Reno and then a shop and see how that five year warranty works. I will post here how all that comes out.
BTW, the DS got to 100% before I finished changing the brake pads on the SR. But most of that time was used trying to find the tools in my so well organized garage <g>.
-Don- Auburn, CA
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What is the voltage when fully charged? Perhaps that will tell you something?
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What is the voltage when fully charged? Perhaps that will tell you something?
I can check that right now.
115.4 volts with 100% SOC indicated.
I think that is usually above 97% SOC on most bikes, probably not enough to show a serious problem, but I would expect it to be more like 116.2 VDC. But I am well within 1%.
I will find the voltage at 50% SOC tomorrow after a short ride. Won't take long at all <g>. There I should expect to see around 101 volts. If significantly higher than 101 volts at 50% SOC, then I will assume it's my SOC that is off, and the battery is okay. However, I expect it to be the battery and see the 101 volts. But I will not assume anything until I check it out tomorrow.
-Don- Auburn, CA
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What is the voltage when fully charged? Perhaps that will tell you something?
I can check that right now.
115.4 volts with 100% SOC indicated.
I think that is usually above 97% SOC on most bikes, probably not enough to show a serious problem, but I would expect it to be more like 116.2 VDC. But I am well within 1%.
I will find the voltage at 50% SOC tomorrow after a short ride. Won't take long at all <g>. There I should expect to see around 101 volts. If significantly higher than 101 volts at 50% SOC, then I will assume it's my SOC that is off, and the battery is okay. However, I expect it to be the battery and see the 101 volts. But I will not assume anything until I check it out tomorrow.
-Don- Auburn, CA
115V is what my 2018 S shows when fully charged and the cells balanced. Which reminds me. I need to pull the charging plug on my bike now. ;)
Oops, I got there too late and when I pulled the charger's plug the charging light wouldn't go off. So I had to turn the ignition on and then off again to get the light to turn off.
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115V is what my 2018 S shows when fully charged and the cells balanced. Which reminds me. I need to pull the charging plug on my bike now. ;)
Oops, I got there too late and when I pulled the charger's plug the charging light wouldn't go off. So I had to turn the ignition on and then off again to get the light to turn off.
Won't it go off by itself within 30 seconds after disconnecting?
-Don- (Rosevile, CA at A&E motorcycles--getting new tires mounted for my TTSE).
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115V is what my 2018 S shows when fully charged and the cells balanced. Which reminds me. I need to pull the charging plug on my bike now. ;)
Oops, I got there too late and when I pulled the charger's plug the charging light wouldn't go off. So I had to turn the ignition on and then off again to get the light to turn off.
Won't it go off by itself within 30 seconds after disconnecting?
-Don- (Rosevile, CA at A&E motorcycles--getting new tires mounted for my TTSE).
Nope, it will stay on for days and slowly drain the battery if I don't turn the ignition on and off, at which time the contactor will click off and the light will go out. I sent the logs to Zero asking them for a comment and received no response. I also complained to my dealer but they said that they had never heard of the problem and had no idea what to do. However, if I can pull the plug within about 10 minutes of the pack reaching 100% and the charging light going solid, I will hear a click and the light will go out. If I wait any longer like I did today, it will not go out. Since it is not a major deal, just an irritation, I put up with the issue. Perhaps it is a minor hardware problem with the charger switch. ???
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Nope, it will stay on for days and slowly drain the battery if I don't turn the ignition on and off, at which time the contactor will click off and the light will go out. I sent the logs to Zero asking them for a comment and received no response. I also complained to my dealer but they said that they had never heard of the problem and had no idea what to do. However, if I can pull the plug within about 10 minutes of the pack reaching 100% and the charging light going solid, I will hear a click and the light will go out. If I wait any longer like I did today, it will not go out. Since it is not a major deal, just an irritation, I put up with the issue. Perhaps it is a minor hardware problem with the charger switch. ???
IOW, the contactor is staying closed when it should be open, when you leave the AC on too long at 100% charged. Weird bugs like that make me wonder if it will be fixed with a FW update. Have you checked?
FW updates can effect some vehicles and not others. And often seem unrelated, but really are.
For an example, the backup cameras in my Tesla would only work ten percent of the time. After the next FW update, they worked perfectly 100% of the time. Few others had the same issue, yet have the same year and model Tesla.
-Don- Auburn, CA
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My bike has had all of the available firmware updates with no impact on that particular problem. However, frankly I have never noticed any difference in my bike with any of the several updates that were sent to my 2018 Zero S with PT. ???
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As the creator of this thread, I'm locking the topic. Diagnose individual battery problems on new threads. I made this thread to discuss a study, but no one's meeting that criteria.