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[siccycle]

Reading Xenoil's post about charging. My understanding is that the Zero's batteries should be charged to full after every ride. The charger is designed to not overcharge the batteries- even at 100% the cell voltage will be at some small amount below anything at all alarming, detrimental etc. I believe it is never detrimental to charge the Zero batteries because of this built in high voltage cutoff.  What is the science (published studies?) on this. Is there anything detrimental to the life of the Zero batteries by charging to full at every ride?

[BrianTRice@gmail.com]

The onboard charger and BMS are designed to condition and balance cel voltage to maximize battery life for all the 2013+ models. Zero's recommendation is "just plug it into an outlet when you can" and experience / customer stories bear that out.

We are no longer in a world where an end user has to think about the conditioning of their battery stacks.

[BenS]

Edit: After reading through the original post again, I just realized that I kind of just repeated it. What I was trying to say is that I think it's best to do what ZERO requires for warranty, and then you'll be covered for long mileage, whether you're on the original packs or replacements. 

This is in the user manual in the warranty section regarding batteries, that they are only covered under proper use.

"“Proper use” also means charging the Power Pack after each use and storing it in a fully charged state, or recharging it every 30 days, or keeping it on the
charger when in storage or not in regular use."

Leaving the charger connected near the end of a charge can give the BMS time to balance the cell voltage, if needed.

I like being able to have the bike fully charged, ready to go at any time!

[Kocho]

There is no one right answer: it is a compromise between priorities. To cite from another forum:

"The loss of capacity per cycle that occurs when Vmax is reduced leads to an overall INCREASE in total lifetime capacity as the extension in life cycles rises faster than the per cycle capacity falls. If you care mainly about highest capacity per charge set Vmax as high as allowed and accept low cycle life. If you can tolerate say 80% to 90% of max possible capacity per cycle, set Vmax lower and get more overall energy storage before replacement"

Read this article and do the math based on the third table:

http://www.batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

You will see that charging to "100%" (even if that is below the max possible) will shorten the life of the battery. So would deep discharges near "0%".

Also, many articles on Li batteries state that topping on with trickle charger is not good for them, nor is it to store them fully charged for a long time.

Read the text near and after that third table. Also read the linked article: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

It appears that keeping the bikes plugged and fully charged for long periods of time without use goes against all of the above, as does routinely running them to "0%" charge to get maximum range per charge.

As mentioned, if one's priority is max. range per charge, they are sacrificing the overall life expectancy of the battery. Over 10-20,000 miles that won't matter too much, but Nissan Leaf and Tesla owners who super charge at high currents and maximize range per charge are losing battery capacity noticeably faster than those who do not. At least we have a choice, but I do not think that's in the manual...

To make a fully informed decision on how to use the Zero chargers "best", we need to know how they work, to what SoC 100% charge corresponds, do they top-up too aggressively, etc., which is not exactly in the manual.

[KrazyEd]

I have to go with what ZERO says.  Generic articles on generic Lithium batteries may be good for a general education when starting out,
but, ZERO knows about how they wish their batteries to be cared for. One of the first things that the manual says is to keep the bike
plugged in when not being ridden or, risk voiding the warranty. My 2012 XU had similar capacity the day it was totaled as it did when
new. My 2013 FX 5.7 is the same.

[grmarks]

I have to go with what ZERO says.  Generic articles on generic Lithium batteries may be good for a general education when starting out,
but, ZERO knows about how they wish their batteries to be cared for. One of the first things that the manual says is to keep the bike
plugged in when not being ridden or, risk voiding the warranty. My 2012 XU had similar capacity the day it was totaled as it did when
new. My 2013 FX 5.7 is the same.

I agree, different battery chemistries require different management. You can't just apply generic rules to every battery. Tesla batteries are affected by charging to 100% but that does not necessarily apply to other chemistries.

[firepower]

this video explains why lithium-ion degrades with charging and how small additives to the mix can increase life dramatically

New additives and manufacture process are increasing  cell life and charge. (Farasis cell zero use have increased from 25Ah to 27Ah in a few years and rumours of another increase.)

High temp and over charging causes most damage. To increase cell life dont take it to extremes of charge and discharge.
As long as you use a charger that monitor cell voltage and current all is good.
Even the fast chargers people make are set to turn off before the Zero charger so it can finish charging at the recommend level.

[Kocho]

So what is the per cell voltage in the Zero that corresponds to "100%" on the dash? Anyone measured?

As for "follow the manufacturer, they know best", it is just blind faith to think this way without specific information. Remember the Vectrix, another US company no longer with us? Their BMS was killing the packs on both their NiMh and Li bikes. Fast. Zero is doing a better job it seems in both charging and quality of the cells. But chemistry is chemistry - there is still a rated limited number of "full" charge/discharge cycles before the battery is expected to degrade down to 80% of its original capacity. The FX battery will degrade the fastest, because due to its smaller capacity it will go through the same number of cycles as the 2.5x bigger S/DS/SR battery much sooner, if they are to travel the same distance. Zero recognizes this and gives shorter rated life/warranty on the FX pack. This indicates that the Zero packs' chemistry is not somehow so good that it does not age. Hence, the guidelines in table 4 in the first article still apply (even if the number of cycles might be a bit bigger for Zero vs. the particular LiPo cells tested there).

Again, the above maybe more of academic interest, given that few bikes will ever test the limits of their battery rated life during a few years of ownership, if Zero is doing a good job with the BMS and the cells are good quality. The age effects might become noticeable after 1000 charge cycles, maybe 2000. That's 20+ thousand miles. We just don't have many bikes on the road with that many miles to tell what happens in reality.

[firepower]

some Tesla cars have exceeded there expected battery life with very little cell capacity loss.
I think battery of today are a lot better then those of 5 or 10 years ago.
Better chemistry, electronics, and understanding cell life at different rates and limits of charge and discharge.

Manufactures and consumers want long battery life. If they cant deliver, they loose confidence and sales and end up same as Vectrix.