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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: PaulZero on June 28, 2020, 04:02:33 PM

Title: SRF / SRS Low SOC restrictions
Post by: PaulZero on June 28, 2020, 04:02:33 PM
Anyone know the official behaviour under CyberIII for low SOC scenario?

I've scanned my SRF manual, and the unofficial manual site and I can't see anything on what the bike will do in a low SOC.  I know (experienced and read about) that at a low SOC the power/torque is reduced.  However, I can't figure out if it's SOC or range based, and what the OS is actually limiting.

Can anyone please shed light on the matter?

Cheers!
Paul.
Title: Re: SRF / SRS Low SOC restrictions
Post by: Hans2183 on June 28, 2020, 09:10:17 PM
As of 10% SOC power and torque are very limited. Top speed is also limited to 120kmh no matter what mode you're in. You notice it most in sport or street mode because of the bigger difference. It's more restricting than eco mode.

I'm not completely sure if so but I thought there was also a limit as of 20%. I'll have to try that again once to be sure. Could be wrong on this.
Title: Re: SRF / SRS Low SOC restrictions
Post by: MVetter on June 28, 2020, 10:56:26 PM
I actually don't know what your question is.
Title: Re: SRF / SRS Low SOC restrictions
Post by: PaulZero on June 28, 2020, 11:36:19 PM
As of 10% SOC power and torque are very limited. Top speed is also limited to 120kmh no matter what mode you're in. You notice it most in sport or street mode because of the bigger difference. It's more restricting than eco mode.

I'm not completely sure if so but I thought there was also a limit as of 20%. I'll have to try that again once to be sure. Could be wrong on this.

Thanks Hans,
The only thing I noticed was at or around 20% but I wasn’t sure if it was SOC based.   I was genuinely annoyed because I wasn’t aware of it, and I struggled to make the overtake I was attempting.  So I’d really like to know for sure so I can allow for it.  I think Zero should bring out an update to permit turning this off - unless if course it’s a battery longevity feature, otherwise the owner should have discretion.  In my case I knew I had plenty of range to reach home.

Any idea if Zero have a formal publication on it?

Cheers!
Paul.
Title: Re: SRF / SRS Low SOC restrictions
Post by: MVetter on June 29, 2020, 01:04:15 AM
This is kind of a standard thing with EVs, really. The problem is amplified on motorcycles because the batteries are smaller. The only motorcycle I've encountered with no power loss all through the battery is the H-D LiveWire.
Title: Re: SRF / SRS Low SOC restrictions
Post by: Zelidar on June 29, 2020, 02:26:05 PM
I was genuinely annoyed because I wasn’t aware of it, and I struggled to make the overtake I was attempting.  So I’d really like to know for sure so I can allow for it.  I think Zero should bring out an update to permit turning this off - unless if course it’s a battery longevity feature, otherwise the owner should have discretion.  In my case I knew I had plenty of range to reach home.

That is indeed an interesting idea and firmware feature which I would appreciate having as well. I hope Zero reads and, if possible, implements your suggestion.
Title: Re: SRF / SRS Low SOC restrictions
Post by: Crissa on June 29, 2020, 04:36:17 PM
Drawing too much power at the bottom end can cause a sudden drop in voltage which would cause the entire bike to freeze up.

It would probably take a different battery configuration.

-Crissa
Title: Re: SRF / SRS Low SOC restrictions
Post by: PaulZero on June 29, 2020, 06:03:34 PM
Hi Crissa,
I didn’t know that, I thought maybe the battery had sufficient charge and voltage at the lower but still usable capacity. 
That being the case then I think the dash turned a Red theme would be ideal.  At least we’d know and not expect the performance of Sport or Street. 
Do you know if it’s at 10% or 20% SOC that low power mode activated?


Title: Re: SRF / SRS Low SOC restrictions
Post by: TireFryer426 on June 29, 2020, 07:34:52 PM
On the SR/F it tapers.  It starts at 60%.
I've only run mine down under 10% once.  There is definitely a power cut at 60%, and if I remember right there was another at 20% and then it really pulled the power back at 10%.
Its definitely SOC where it imposes the limits, and as other have said its torque output and top speed.
Title: Re: SRF / SRS Low SOC restrictions
Post by: Crissa on June 30, 2020, 01:30:18 AM
It's just a fact with battery function that when the voltage crash occurs is connected to amperage draw; lower amperage, lower chance for going off the voltage cliff.  The cliff is somewhere, you just don't want to go over it.

That's why with older devices you'll often get crashes at the end of battery life.  The device asks for more amperage, and it's just not there and then the voltage falls off (and then the device crashes).  This happens at the bottom of capacity, whether new or old - it's just the bottom creeps up as the cells age.

It's also one of the reasons the bike does cell balancing.  So that it doesn't encounter this.  Packs with lots of sub-cells (like Tesla's or Porsche's) are less likely to have this problem as the amperage is averaged out over the whole.  But it does raise the price a bit.   Bike are just smaller and necessarily have fewer cells, so will encounter this more easily.

The question with design becomes a triangle choice:  More cost, have a limit, or risk premature shutdown.  Pick one. ^-^

-Crissa
Title: Re: SRF / SRS Low SOC restrictions
Post by: Zelidar on June 30, 2020, 03:37:22 PM
... It's also one of the reasons the bike does cell balancing.  So that it doesn't encounter this.  Packs with lots of sub-cells (like Tesla's or Porsche's) are less likely to have this problem as the amperage is averaged out over the whole.  But it does raise the price a bit.   Bike are just smaller and necessarily have fewer cells, so will encounter this more easily. ...

Learning new things all the time on this forum, thank you Crissa.

Since we are speaking about SoC and firmware, what I would love to have is a function which will charge up by default at, say, 60% unless I press a button within x seconds upon which it will get to 100%, or the other way around 100% instead of 60%. The idea behind it is to have the battery at 100% for the overall least possible time. Currently, I only charge in the morning, or just before riding, so that the battery does not stay at 100% for hours at length. Setting a time where I want the battery to reach 100% would probably be the nicer option.
Title: Re: SRF / SRS Low SOC restrictions
Post by: Crissa on June 30, 2020, 10:07:20 PM
The F-platform bikes do have a default max charge point you can set in the app.

I think there's some simple button press to override this when you need to.

-Crissa
Title: Re: SRF / SRS Low SOC restrictions
Post by: Hans2183 on July 01, 2020, 02:17:31 PM
Indeed you can configure a target SOC to charge to within the app plus a delay in hours and a window in which the delay should be applied.

When you have one of these set you'll get a popup if you switch the bike on while plugged and then you can use the menu control on your left hand to select and confirm "override" to ignore this delay or target.

If you have both options enabled and you are within the delay time you can override twice. There is a glitch where you have to confirm override once, then move the selection and go back to override in order to confirm a second time.

I have mine set to 80% and only override it when I have a longer distance to ride. Often I only override it in the morning then when I prepare.

The window I use to delay charger to night time but only as of 17u since if I want to charge earlier I probably didn't make it home yet.
Title: Re: SRF / SRS Low SOC restrictions
Post by: Zelidar on August 25, 2020, 07:16:36 PM
It took me a while to adopt Zero's methods with scheduled charging, charge target and overriding them both when I need (no mention of override in the owner's manual by the way *). I am finally using both and am also very glad that these functions were made available to me. Thank you Hans2183 for motivating me to try that again.
(* 2020-Zero-Owners-Manual-SRF.pdf)