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[DerKrawallkeks]

I don't know if the aging gets less over several years, I should check;)
but it's not like they have 79% after 5 years. I think a healthy battery even if kept at 100% is gonna have more life. The aging is much less at the average temps that our batteries have, being outside. Depending where you live, the average is probably like 15°C.

[ESokoloff]

Lots of discussion on Max SoC but not so much on Min running SoC. 
My past battery spent a lot of time on the low end & I’m wondering if that isn’t more harmful then max non storage SoC.

Using my typical usage as an example (40% each leg of commute with New charge pattern, I E charging each leg).........
I agree that 70% would be easier on the battery then 80% but I feel the greater harm would be running @ 30% vs 40%.

For the most part we all charge up to 100% but how many here have consistently utilized the full spectrum of SoC?

I have for years & thousands of miles & this pattern had to have had an impacted on battery SoH (State of Health).

[princec]

Very low SOC is much worse than high. Once the voltage drops below a certain threshold, copper dendrites form irrevocably and in the worst cases short out the batteries causing a fire.

Good link here:
https://www.cassindustries.com/lithium-ion-battery-safety-failure-causes/#:~:text=Copper%20shunts%20form%20inside%20the,Li%2Dion%20than%20regular%20cycling.

Cas

[Richard230]

About 10 years ago, while I was attending an electric car conversion event, I struck up a conversation with a fellow who insisted that the best way to balance battery cells was when they were at a low voltage state. That was the only time that I had heard that before or since. At the time it seemed to make some since, but running the battery pack until it was almost depleted and then balancing the cells before recharging seemed like a lot of work to me and probably something that a typical customer of a mass produced EV would likely not want to do.

[JaimeC]

I used to race R/C model cars.  We'd fast charge at the track between heats but the night before the event, the practice was to trickle charge the packs to allow the cells to balance for maximum performance and life.  The slow charge allowed each cell to charge to their fullest capacity; fast charging generally only charged MOST of the cells to their full capacity.  There was a lot of effort made into matching the cells used to build each battery pack but there are ALWAYS inconsistencies.

Mind you, back then the technology used for rechargeables was NiCad, not Li-ION... but I would think the philosophy would be pretty much the same thing...

[DerKrawallkeks]

@princec Very low SoC really is bad, but our Zero batteries have 3.4V when at 0% indicated SoC (at least mine is). That's very different from 2V or crazy things like that. Some other batteries like in laptops regularly go down to 3V. So 3.4V is no problem at all, and very healthy for the battery.

@Richard230 This is called bottom balancing. It's not much of a difference, but since our batteries (unfortunately) spend most their time full or highly charged in the garage, manufacturers want the cells to be balanced during this condition.
With our super-well matched cells straight from the same production line, most of us don't need to worry about balancing.

[princec]

I guessed Zero had intentionally chosen 0 and 100% SOC voltages that were extremely conservative for the battery so that they weren't hit with thousands of warranty claims.
I wonder if the new 10% "range" charge boost that's being talked about in the other thread about new model updates is their relaxation of the current 100% SOC limit after extensive testing has determined it to have little effect on longevity.

Cas

[DerKrawallkeks]

Yup I agree with you, I think the 4,15V and ~3,4V limits are conservative (and smart;))
The range boost is probably just what you said. For example even Farasis themselves rate their cells up to 4.2V, so they could be doing this, or they could go a little bit further down.

My guess would be going further down, since they spent less time there, while the impact of having the cells sit at 4.2 vs 4.15V all the time (plus cycling them up to 4.2V in addition to that calendar aging) would make quite a difference.

[gt13013]

our Zero batteries have 3.4V when at 0% indicated SoC (at least mine is)

Hello. Where do you get this information?

On my 2016 FXS, I have two separate battery packs and I get logs for the BMS and for each pack. The logs give constantly the SOC, the  battery voltage, the higher battery cell voltage, the lower battery cell voltage (and many other information).
Here is an example from another topic : https://www.electricmotorcycleforum.com/boards/index.php?topic=5314.msg107059#msg107059
I attach an example where I tested a full depletion of the battery. And from this log, you can see that in the case of my bike the voltage goes down to about 3.1 V. But it is still a safe value.