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[PaulZero]

For those with 6kW+ charge capability, have you noticed that the bikes' discharge rate is exceptionally high immediately after a 6kW+ charge?
I have consistentently seen the first 20% SOC after a fast charge drop off in about 5 miles of travel and I don't have to push the bike to see this drop off.  The SOC then settles to my usual 1% per mile average.  I have a SR/F premium.

I am considering the charge tank upgrade but this behaviour is causing me to question this if this situation could be worse as a result. 

[kasmtk]

Probably to do with the battery being hot after fast charging.. leave it to cool for a time


Sent from my iPhone using Tapatalk

[JaimeC]

Can't say I've noticed this with my 2018 S model...

[TEV]

Not happening, 2019 Zero DSR charging at 12KW (Double J-ing).
Now the questions are:
1. Do you wait for the charging session to end , or you unplug as soon as you're at 100% ?

2. What is you cell ballance before you start charging, after you finish charging,  and after is dropping fast the 20% ?

[PaulZero]

How do I determine cell balance?
I don’t run the charging session until I have 100% SOC, I usually finish at 80% to carry on my journey.

[TEV]

How do I determine cell balance?
I don’t run the charging session until I have 100% SOC, I usually finish at 80% to carry on my journey.

The cell balance value should be in the phone app. 10mV or lower is a good value. You have to let the battery fully charge to 100% and leave it plugged for a while after it's at 100% to give it time to do the cell balancing.
How often do you charge to 100% , and let it stay plugged in for a few hours after that ?

[PaulZero]

Hmmm, I don’t see anywhere in the Zero Next Gen app with cell balance information.
I very rarely fully charge my bike. 3000 miles on it and I think I’ve fully charged maybe twice. When I overnight charge I use the charge target feature to take it to 85% usually - plenty for my commute or a one-way trip, then fast charge at the other end for an hour. 
I always thought ‘best practice’ was to keep within 20%-80% (roughly)?

[PaulZero]

Just found this thread : https://electricmotorcycleforum.com/boards/index.php?topic=8130.0
I have the SR/F and I think only the 'older' Zero app has the cell balance figures.   I don't think the Mext Gen app does.

[TEV]

Hmmm, I don’t see anywhere in the Zero Next Gen app with cell balance information.
I very rarely fully charge my bike. 3000 miles on it and I think I’ve fully charged maybe twice. When I overnight charge I use the charge target feature to take it to 85% usually - plenty for my commute or a one-way trip, then fast charge at the other end for an hour. 
I always thought ‘best practice’ was to keep within 20%-80% (roughly)?

You should download the manual from Zero website and see what it's recommending about charging and ballancing.
My guess is that your cells are way out of ballance,  and it will take a while to get them back in ballance,  but I may be wrong, I have a DSR,  not a SR/F, so I didn't read the SR/F manual.

[MrBlc]

@PaulZero
For longevity of cycle life of the battery, doing quick charging in that range, yes that is best.
Over time however, the batteries will develop a unbalance between them, which is what you have been getting information on here in this thread.
This unbalance means that one cell is discharging faster than the others as it has more charge in it than the others.
This is a result of difference in internal resistance and even though Zero tries to match this as best as possible, it is impossible to eliminate.
When you experience this behavior (sudden drop for a few %'s) it usually indicates an imbalance, and it's fairly easily resolved by having the bike slow charge all the way to 100% sometimes, and then let it be connected to the charger until balancing has finished.
Depending on how large of a difference there is, this could take several hours..

[PaulZero]

@MrBlc thanks for explaining.  This is my first EV so it’s all new. 
Ya gotta wonder then why it seems the ‘Next Gen’ app is missing the Cell Balance information. Appears to be just a guessing game.  For me there are quite a few Battery behaviours that are neither explained in the manual nor presented in the dash or the app.  Such as the drop off of power as SOC drops, limp mode (I hate not knowing when the bike has entered this state) and now cell balance.  I guess over time I’ll just get used to but I shouldn’t have to.  This is probably ‘fixable’ in a firmware update or app update so here’s hoping. 😉

Cheers!

[MrBlc]

@PaulZero
Happy to help
I suspect they obfuscated that information to not worry customers with the intricacies.. It tracks with how they have, over time, removed more and more advanced information and access over time.
Easiest way to handle this would be to follow this:
- QuickCharge like you are used to
- Store at 80% or below when parking for extended time (more than a day)
- Do a 100% charge the night before going on long trips
- Do a 100% charge when you have the time to follow up on it and check that everything runs smoothly

That should cover most use cases, and give you an as low as error filled experience as possible. At least in relation to battery and charger.

[DonTom]

@PaulZero

- Store at 80% or below when parking for extended time (more than a day)

I think you should add to NOT store below around 30% or so.

-Don-  Reno, NV

[PaulZero]

Feedback on the help provided above...
On the SR/F and I assume SR/S you need to use Charge Target if you want balanced cells but not 100% charge.  So for example if I am out and I pull into a charge station and I plan on reaching 80% because that’s all I need or based on time then I need to set the charge target to 80%.  Then the amperage will start to drop as soon as the bike hits 80%, I assume this is the BMS balancing the cells after hitting the target.  The amperage dropped from 57A down to 6A over the course of 10mins.  So for the extra 10 mins with seemingly no benefit (same SOC) the bike indeed performed at my usual 1% per mile.  I really think Zero should have kept the cell balance info, but I can now judge based on how quickly the amperage drops after the target is hit. 
Learning lots every day with this amazing machine! 👍