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[DynoMutt]

Would this tradeoff on the battery discharge rate also be impactful re: charge times?

Would it explain perhaps the reason that CHAdeMO is no longer an option for 2015?

[protomech]

Possibly. The smallest S bike has a 0-95% charge time of 1.4 hours with 4 accessory chargers, which isn't much longer than CHAdeMO charge time.

[firepower]

I sure CHAdeMO would still be an option for fleet customers.

Quote from aaronzeromoto

"In terms of the experience, the biggest issue remains potential incompatibility with CHAdeMO stations that are not fully compliant with the specification. Our solution and our motorcycle's electrical architecture requires support for voltages below 200V.  You'll find some posts on the forum describing this in more detail if you are interested. Some charging stations chose simply to stop at 200V, which is why you can't buy one of these unless you talk to me. We don't want you to be disappointed.  Today, it's really a better solution for our Fleet customers that are installing a known compatible charging station or someone that knows they have access to a compatible station (typically a Nissan one)."

http://electricmotorcycleforum.com/boards/index.php?topic=3637.msg21348#msg21348

[protomech]

According to my calcylations the new 2015 battery are now using Farasis 27Ah pouches instead of 25Ah (2013-2014)

Official confirmation of the 27 Ah cell.

Originally posted at http://www.farasis.com/news.html

October 2014

Leading the way in Li-ion battery performance, Farasis Energy is excited to introduce the 27Ah pouch cell design. A 10% capacity increase over Farasis’ previous capacity pouch cell designs, the 27Ah will be featured in Zero Motorcycle’s up and coming 2015 line up. See Zero Motorcycle’s press release to learn more.

[kensiko]

Did I get this link here ?



Anyway, just listened until 35 minutes. Our battery is the second one on graph at 26:33.

[firepower]

Excellent video,  deserves it own forum post.

[Burton]

Watched full video.

The key takeaway for our current bikes is to reduce the time spent with cell voltages above 4 to reduce the scale building. I believe my 2013 SR has the individual cell voltage set to 4163mv by default in the MBB. Changing this to 4 might increase the life of the battery at the expense of range.

Terry kind of does this but differently. He charges to 100% right before leaving versus letting it trickle charge over night. This way the time spent at higher voltage is reduced.

For those who store their bikes over winter it might be great to reduce the cell voltage cutoff via the MBB interface for the winter to keep the cells at 50% SOC.

High temperature is also a big factor with our bikes. Trying to keep the battery as cool as possible all the time will reduce the oxidation in the cells. Not sure how we can really fix this ourselves outside adding cooling components to the bike. Would doing this likely increase the risk of condensation though?

[Justin Andrews]

Yeah, I think its been mooted before that storing your bike around the 40% - 50% mark is the most conducive to long life.

[Burton]

Yeah, I think its been mooted before that storing your bike around the 40% - 50% mark is the most conducive to long life.

Yes, but how many people are using their ODBII connector to set the bikes charge limit cutoff point

[Doug S]

Yeah, I think its been mooted before that storing your bike around the 40% - 50% mark is the most conducive to long life.

The more extreme a charge OR discharge event is for a rechargeable battery (any rechargeable battery, even "deep cycle" batteries), the harder it is on the battery. When the Prius first came out, people were screaming that the battery pack would have to be replaced every year as the batteries "wore out"...but there are now Priuses (Prii?) running with well over a quarter of a million miles on their original battery packs. Toyota engineers wisely limited the SoC of the batteries to the 40-60% range, so they only use 20% of the battery's capacity, but treating them so gently extended the useful life of the battery by a huge amount, well into "it's not a problem" territory.

Modern batteries give better results than the NiMH batteries of fifteen years ago, but it's still true, and will probably always be true, that efforts to get more capacity out of a battery by charging just a few millivolts higher, or discharging just a few millivolts lower, are always going to reduce the life of the battery. The engineers of the vehicle have to balance useful battery capacity against battery life, and their balance point isn't necessarily the same as yours as a consumer -- the manufacturer is always going to be motivated in large part by the advertising value of greater battery capacity. That's why I personally don't like to see my SoC indicator drop below 30%, and will try very hard to keep it from ever going below 20%. I'd rather plan my affairs around slightly shorter range and have my battery pack last longer.

[GdB]

A good article but one missing point is the stress caused by 100% full charge. 
From what I understand most of the cell wear is caused by full charge.

I usually do not charge my i-MiEV batteries to 100% when I don't need it for short commutes.  It has Lithium Titanate cells rated at 3000-7000 cycles.

So it makes even more sense to do the same for the Zero NMC cells rated at 1000-2000 cycles.

http://batteryuniversity.com/learn/article/types_of_lithium_ion]Ref: [url]http://batteryuniversity.com/learn/article/types_of_lithium_ion[/url]

[MostlyBonkers]

Thanks for your comments G.

I did mention that it's best to store Li-ion batteries at 40-50% state-of-charge but it doesn't hurt to point out that keeping them fully charged isn't necessarily the best strategy.  I think that leaving them at a very low SoC is the most harmful and you also run the risk of the battery being bricked if it drops below the minimum.

My main motivation for writing that article was to try and reduce some of the anxiety around battery charging. Most people just want to plug their EV in when they get home so they always have a full charge ready and waiting. They don't want to have to think about how long their next journey is likely to be. They also don't want to have to remember to top up the batteries if they are going on a long trip. I want people to understand that it's ok to leave an EV plugged in all the time, if that's how you want to use it. The engineers who design these things have accounted for that and you'll get good battery health for at least the length of the warranty.  For most people that's enough. They'll want a new car or certainly bike at least every five years and they just don't care.

People like you and I are a little different though. We want to take some care and want to get the most out of the things we buy and spend a lot of money on. You might want to keep your Mitsubishi for ten or fifteen years if it does the job. My Hyundai Getz is twelve years old and running well.  In that case, you want to be doing exactly what you are doing. The last thing you want is a bill for a new battery pack after eight to ten years. I'd be upset if my Getz needed a new engine at ten years, which is arguably one of the most expensive components.

For most people, my message is: Don't hassle it, keep it plugged in. For the rest of us it's: A little bit of planning will give you a longer service life.

I know that if I was to buy second-hand I'd want a good way of measuring the battery health!

Thanks again G, I am actually agreeing with you even if it might not seem that way in some respects! [emoji4]

[siccycle]

Great Reading- Thank You Mr. Bonkers I leave my Zero plugged in all the time. I believe the Zero engineers have designed the charger to not overcharge. That 100% is not really 100%- that it is a value that in no way compromises the longevity of the cells.

But if Burton's comments about over 4 volts are helpful, then where does that leave our 'leave it plugged in' strategy?

I guess my question is- How do we program our MBB (Main Bike Board) to shut off at say 98%? Is this too far off topic for this thread?  Reprogramming sounds quite 'techy'. But I would certainly enjoy learning more. Are there any threads that have this covered? Thanks

[buutvrij for life]

Very good piece of work, Bonkers. I've spent several hours reading battery University for the last 2 years, as my life depends more and more on battery tech, and this is a very good summary in relation to our bike's, and as you said; for people who like to take a little more care of their wheels!

I have a question about batterytemp/charging:

If my info is correct, Zero tells us not to charge or avoid charging below freezing point. (or the BMS won't allow it)
When my DS is resting, it's battery temperature is always some 10 or 12 degrees higher then its surrounding temperature. I'm talking Celsius here.
Would that mean that i could charge the bike when it's -minus 5 degrees celsius? (battery temp would then be 5 degrees above freezing point)

The reason i'm asking is because we have mild winters over here, and mostly, temperatures are close to freezing point, and i do like to take a little more effort to keep stuff in good condition   My bike is always in the non-heated basement of my house. Is my thinking to simple or what?

[MostlyBonkers]

I'll try and answer the last two posts and thanks for your feedback.

The strategy of leaving the bike plugged in all the time is ok, after all it's what they tell you to do in the manual. There are lots of practical reasons why you would want to do that, convenience being at the heart of it. It is worth considering an alternative strategy if you don't use your bike every day. You could, for example, buy a timer and charge the bike for long enough to bring it up to 50% after your ride. You'll know from experience how long to set the charging time for depending on the state of charge left.  You could also set the timer to come on a few hours before you want to ride the bike again to bring it up to a full charge. If taking that approach, you will still want to leave the bike plugged in for an extended period occasionally to allow the BMS to balance the cells.

If the ambient temperature is at or below freezing, I would not attempt to charge the bike even if the battery thinks it is warm enough. If the bike has been standing for a long time, all of the components will be at the same temperature. It's likely that the temperature sensor is reading inaccurately.

I hope that helps.