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[DonTom]

I started with 81% SoC, s

Me as well as a guy I know with a Zero SR/S have discovered that if you START a charge at 80% it will charge at a MUCH lower rate than when it gets to 80% when started at 70% or below.

So now I never start a charge at 80% or above.  I will usually only get a 2 KW charge with 6.3 KW of chargers. I get the exact  same rate if I remove 2.5KW worth of charging. Makes no change at all when I start the charge at 80% or above.

But I will get close to around 6KW at 80% SOC if I start the charge at  less than 70%.

Why?  I have no idea. But I have seen it happen several times. It can be very confusing at first, until realizing it only happens when starting the charge at above 80% SOC or so (I cannot give an exact SOC, but AFAIK, it will NOT happen if you start the charge at least 10 SOC below the 80%).

-Don-  Reno, NV

[enaef]

Attached a new recording of charging behaviour this evening.

[Crissa]

Well, that's pretty definitive.  It doesn't pop back to the original curve quickly, it starts a new arc down to the charge target.

That's totally not how it should work.

-Crissa

[enaef]

For me the question remains, if this behaviour is intended and if so, for what reason.

Also, the estimated remaining charging time seems not to include the curve in its calculation.

The estimated remaining charging time seems to be calculated only by the kW which work right at the moment and uses this linearly until the target - instead of including the coming curve.

If you look at time stamp 18:10:05 the estimation is 2 minutes. Actually it took 12 minute until the shut down. And this was with 7.1 kW going in.
At a 22 kW station with ~11.5 kW going in, the difference will be even bigger.

Of course, with a SR/F or /S standard with only one 3 kW charging module the difference will be smaller and less obvious.

[Richard230]

I don't understand why Zero would change the charging curve for the SF/S models, compared with what they use for the legacy S models.  On my 2018 S with PT, it charges at 120V without any tapering, according to my Kill-A-Watt meter. The charger/BMS goes full-bore at 12 amps until it shuts off without any reduction. When I check the cell balance using the Zero app, balancing shows 2-3 mV. Also the estimated charging time when checked shortly after first plugging the OBC in is right on the button. So no complaints here. 

[DonTom]

I don't understand why Zero would change the charging curve for the SF/S models, compared with what they use for the legacy S models.  On my 2018 S with PT, it charges at 120V without any tapering, according to my Kill-A-Watt meter.

At a 1.3 KW charge, it's not all that much of an issue. Not much there to taper off.

-Don-  Auburn, CA

[alby62]

ma voi in america  avete il caricatore  da 9 kw ??'!!!!! che ...fortuna

[alby62]

ehi  don ton hai  avuto anche  tu una  stelvio ' la mia però era del 95

[DonTom]

ma voi in america  avete il caricatore  da 9 kw ??'!!!!! che ...fortuna

(but you in america have the 9 kw charger ?? '!!!!! so lucky)

On some Zeros, 12 KW charging is available.

12 KW AC  is sometimes available from Tesla Destination charge stations using a  50 amp Tesla-Tap.


-Don- Auburn, CA USA

[DonTom]

ehi  don ton hai  avuto anche  tu una  stelvio ' la mia però era del 95

(hey Don you too had a stelvio 'but mine was 95).

I still have my 2016 Stelvio. I ride it fairly often, but not nearly as much as my Zeros.


-Don-  Auburn, CA USA

[enaef]

So - out of interest I asked my dealer if he would enquire Zero about the reason of this chargin behaviour. I assumed I would get an answer quicker than if I contacted Zero myself.

According to Zero cell balancing is indeed (also) done at the end for all charging targets under 100%

[Crissa]

That's not a good behavior   Cell balancing at a target needs to be optional.  Especially when you're on the road!

I can see why you might want it say, if you were charging to 80% every night.

-Crissa

[enaef]

Therefore I'm going to deactivate the charge target when I'm on the road. Balancing then will start to kick in earliest at ~85% SoC I guess. Up to 90% I will still have quite a decent rate. At that point I will have to decide how much I'm in a hurry (or bored) and how much SoC I'm really going to need until the next charging opportunity.

[TheRan]

Perhaps I'm mistaken but I always thought balancing happens after the battery has finished charging (whether it's to 100% or 80%), and that it has nothing to do with the charge rate tapering off at the end. On the older models with no charge target they will get to 100%, tapering off as they approach that, and then once they're at 100% the charge light will stay lit for like 10-15 minutes as it's balancing and the bike will be drawing much less from the mains, like in the hundreds of watts instead of thousands (maybe in the tens, it's been a while since I monitored it).

[Richard230]

Perhaps I'm mistaken but I always thought balancing happens after the battery has finished charging (whether it's to 100% or 80%), and that it has nothing to do with the charge rate tapering off at the end. On the older models with no charge target they will get to 100%, tapering off as they approach that, and then once they're at 100% the charge light will stay lit for like 10-15 minutes as it's balancing and the bike will be drawing much less from the mains, like in the hundreds of watts instead of thousands (maybe in the tens, it's been a while since I monitored it).

Using a Kill-A-Watt meter, I have seen different patterns in charging between my old 2014 S and my 2018 S. The 2014 model would seem to slow its charging occasionally like it was taking time out to balance the battery cells and before it would shut off charging would slow to about 250 watts for several minutes. However, my 2018 S just charges at 12 amps until it shuts off, without tapering the charge, which happens about 15 minutes after SOC shows 100%. I don't know what is going on, other to say that both bikes seem to do a good job keeping the battery cells balanced, with 2-4 mV showing on the Zero app after the charger turns off. It would seem to me that Zero's thoughts regarding how to recharge their battery packs is constantly evolving. 

My daughter owns my old 2014 S (with PT) and yesterday she rode it to my home along the same route that I take to visit her on my Zero. She used 32% SOC to travel the 37 miles to my home. When I take the same trip riding my newer Zero with a slightly larger battery pack, it usually takes 30% SOC. So I would have to say that her batteries haven't degraded very much during the past 6.5 years that the bike has been in use. I might add that on the 2014 model, the charger remained plugged in all of the time for about three years. before Zero's revised recommendations were published.