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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: EDoggN on June 28, 2019, 06:16:28 PM

Title: Zero SR/F - Newbie Charging Question
Post by: EDoggN on June 28, 2019, 06:16:28 PM
Hello all!  I am new to the forum and Electric Motorcycles in general.  I currently own a Tesla Model S and Model 3 and love the electric lifestyle.  I test drove a Zero SRF a few days ago and haven't been able to shake my desire to buy one.  I have a question about charging that I am hoping this forum can help me out with.  When you plug the bike into a power source I see that you can set a charge limit (80% for example), however the manual recommends that you should unplug the bike when the charge is complete.  My question is, since the computer on the bike is stopping the charging process automatically why do you need to unplug it?  The Tesla's have a similar charging setup and once you plug them in you don't have to worry about unplugging them.  Zero makes it sound like you can damage the battery by leaving it plugged in...is this true?
Title: Re: Zero SR/F - Newbie Charging Question
Post by: Jarrett on June 28, 2019, 06:34:14 PM
In the past, I understand that Zero said to leave them plugged in all the time.  At some point, that guideline changed.

My completely fact-less based speculation is that they had some number of them burn when left plugged in for a long time, so now the manual says to unplug them.

That could be completely false, but I assume that's the reason for the change.

I personally leave mine plugged in longer than it takes to charge it to 100%.  For example, if its going to reach 100% at 3am, I don't get up and unplug it at that time.  I wait until I am in the garage next to unplug it.

Also, once unplugged, my DSR will start slowing draining itself.  My FX doesn't do that, it will stay at 100% until you ride it again.  Not sure why the difference there.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: NEW2elec on June 28, 2019, 07:00:05 PM
The SRF is new and a different platform and can stop the charging process at any state of charge.  The old bikes can't. 
At this point I don't know what the SRF manual says about staying plugged in after charging to your desired SOC but the current "unplug after 100%" recommendation would be for the old bikes.

The pouch cells at 100% expand slightly and prolonged time at this state plus high outside temperatures could cause the pouches to be over stressed.

Your SRF can do what you want so the only reason to unplug that I can see is keeping say a lightning strike power surge from reaching the bike and "maybe" if after the bike stops charging at say 80% it no longer knows you plugged in and moveing the bike could damage your charging cord. 
The last one is more far fetched but that's all I can think of for the SRF, which again the "unplug" advice may not even apply to.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: alko on June 28, 2019, 07:07:16 PM
In the past, I understand that Zero said to leave them plugged in all the time.  At some point, that guideline changed.

My completely fact-less based speculation is that they had some number of them burn when left plugged in for a long time, so now the manual says to unplug them.

That could be completely false, but I assume that's the reason for the change.

I personally leave mine plugged in longer than it takes to charge it to 100%.  For example, if its going to reach 100% at 3am, I don't get up and unplug it at that time.  I wait until I am in the garage next to unplug it.

Also, once unplugged, my DSR will start slowing draining itself.  My FX doesn't do that, it will stay at 100% until you ride it again.  Not sure why the difference there.

There's something wrong with your dsr if you notice it draining after unplugging it. Mine doesn't do that nor should any of them.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: Jarrett on June 28, 2019, 07:51:39 PM
Zero told me:

"drops in SOC over a long period of time are normal."

Not sure what a long period of time is though.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: alko on June 28, 2019, 08:52:51 PM
Zero told me:

"drops in SOC over a long period of time are normal."

Not sure what a long period of time is though.

Yes over a long period of time (which im guessing weeks if not months), but didn't you just get the dsr?
Title: Re: Zero SR/F - Newbie Charging Question
Post by: pacificcricket on June 29, 2019, 01:21:35 AM
The SRF is new and a different platform and can stop the charging process at any state of charge.  The old bikes can't. 
At this point I don't know what the SRF manual says about staying plugged in after charging to your desired SOC but the current "unplug after 100%" recommendation would be for the old bikes.

The pouch cells at 100% expand slightly and prolonged time at this state plus high outside temperatures could cause the pouches to be over stressed.


Pretty sure you misunderstood the whole problem. First of all, neither new or old bikes truly charge to 100% in terms of the cells' operating limits - the cells are being cycled something like 20 to 95 % of their range,
which is presented to you as 0-100% on the dash. Then, the old bikes can also stop charging at any time - BMS simply disconnects the charger, and it doesn't matter whether AC power is still supplied, but the threshold
is not user-programmable. Finally, the original issue revolved around "floating". After sitting for a while, self-discharge drops the SOC below certain point where BMS re-activates the charger to top off what was lost.
That cycle can be repeated many times, depending on how long does the bike sit plugged in, and that's what was undesirable for the cells' longevity.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: EDoggN on June 29, 2019, 01:38:11 AM
If that is the case, it Seems like this would be an easy problem to fix??  Once the charge limit is reached,  make it where the operator manually has to re-activate the charging.  This would make the same as unplugging.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: Jarrett on June 29, 2019, 01:41:12 AM
Zero told me:

"drops in SOC over a long period of time are normal."

Not sure what a long period of time is though.

Yes over a long period of time (which im guessing weeks if not months), but didn't you just get the dsr?

Maybe I'll swing it by the dealer.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: pacificcricket on June 29, 2019, 02:04:26 AM
If that is the case, it Seems like this would be an easy problem to fix??  Once the charge limit is reached,  make it where the operator manually has to re-activate the charging.  This would make the same as unplugging.

Absolutely agree, it's a software deficiency. Though there is a side-effect - if you in fact intend to store bike for months at a time, Zero advises to plug it in then to prevent discharge below critical level and damage to the cells. They're kind of picking between two evils. Now if I understand correctly, there is a "storage mode" available in the software in the newer models which addresses that use case.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: DonTom on June 29, 2019, 02:31:23 AM
My question is, since the computer on the bike is stopping the charging process automatically why do you need to unplug it?  The Tesla's have a similar charging setup and once you plug them in you don't have to worry about unplugging them.  Zero makes it sound like you can damage the battery by leaving it plugged in...is this true?
I think they need to update the manual for the SR/F. I see no reason to ever unplug either the Zero SR/F or the Tesla as long as you're not charging to full.

I rarely drive my Tesla M3 during this time of year. I have it plugged in at all times to start charging at 2300 hrs until it gets to 80%. So it always stays at 80%. I see no reason why you cannot do the same on the SR/F, if only charged to 60%. No real reason to ever unplug it, IMO, but I would also set a charging time to charge at to 60%, if not being used.

If being used a lot, I would set it at a higher SOC.   But charge to 100%  only when you think you may need it.

-Don-  Auburn, CA
Title: Re: Zero SR/F - Newbie Charging Question
Post by: NEW2elec on June 29, 2019, 10:53:42 AM
The SRF is new and a different platform and can stop the charging process at any state of charge.  The old bikes can't. 
At this point I don't know what the SRF manual says about staying plugged in after charging to your desired SOC but the current "unplug after 100%" recommendation would be for the old bikes.

The pouch cells at 100% expand slightly and prolonged time at this state plus high outside temperatures could cause the pouches to be over stressed.


Pretty sure you misunderstood the whole problem. First of all, neither new or old bikes truly charge to 100% in terms of the cells' operating limits - the cells are being cycled something like 20 to 95 % of their range,
which is presented to you as 0-100% on the dash. Then, the old bikes can also stop charging at any time - BMS simply disconnects the charger, and it doesn't matter whether AC power is still supplied, but the threshold
is not user-programmable. Finally, the original issue revolved around "floating". After sitting for a while, self-discharge drops the SOC below certain point where BMS re-activates the charger to top off what was lost.
That cycle can be repeated many times, depending on how long does the bike sit plugged in, and that's what was undesirable for the cells' longevity.

Well I'm not really understanding you.  :)   
The first part I know and agree with the dash 100% SOC isn't a true cell limit 100%.
If they were working the way the new SRF bikes do then the older Zero's BMS "could" turn off the charger at a set SOC but as they are now if you want the bike to stop charging at 80% SOC you have to unplug it from the wall.  The BMS will "only" stop the charger at 100% SOC.

This next statement makes me wonder if you saw the new charging recommendations from Zero.

Quote from Pacificcricket :  if you in fact intend to store bike for months at a time, Zero advises to plug it in then to prevent discharge below critical level and damage to the cells. They're kind of picking between two evils.

They say "don't" leave it plugged in even for storage.  You need to check on it monthly and charge if needed.
Link to Zero's web page on the subject :   https://www.zeromotorcycles.com/owner-resources/charging-recommendations/

The truest reason as to why this change was made is up to debate.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: alko on June 29, 2019, 06:50:33 PM
Zero recommendation also says keep SOC between 30-60% during long term storage.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: DonTom on June 29, 2019, 09:20:50 PM
"After each use, you should plug you motorcycle into an AC power source to recharge. Once it is charged, you should disconnect it from the AC power source. Leaving your motorcycle unplugged will maximize long-term power pack health."

Why should it make any difference to the battery if it is plugged in at 100% or not? The contactor will then be open anyway, and charging is stopped, plugged in or not, right?

-Don- Auburn, CA
Title: Re: Zero SR/F - Newbie Charging Question
Post by: pacificcricket on June 29, 2019, 10:18:56 PM

They say "don't" leave it plugged in even for storage.  You need to check on it monthly and charge if needed.
Link to Zero's web page on the subject :   https://www.zeromotorcycles.com/owner-resources/charging-recommendations/


That's fine, but really that's a problem with their software. If they were to implement proper logic to control the charger, none of that would be a problem.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: pacificcricket on June 29, 2019, 10:27:15 PM
Why should it make any difference to the battery if it is plugged in at 100% or not? The contactor will then be open anyway, and charging is stopped, plugged in or not, right?

Quote
After sitting for a while, self-discharge drops the SOC below certain point where BMS re-activates the charger to top off what was lost.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: NEW2elec on June 29, 2019, 10:34:15 PM
I 100% agree.  The app is the only way I can think of to even access it, as is, and even then I doubt they built in a way to talk to the BMS from the app.

But for now they want it unplugged for all the sub 2020 models.


+1 on your second statement to DonTom as well.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: NetPro on June 30, 2019, 09:33:41 AM
"After each use, you should plug you motorcycle into an AC power source to recharge. Once it is charged, you should disconnect it from the AC power source. Leaving your motorcycle unplugged will maximize long-term power pack health."

So, they are recommending to recharge after each use ???
But, let's say you go out for a short ride (mostly my riding style) and there is plenty of juice left to do it again several times.
Does recharging after a ride where you used, say 10% of the full charge, counts the same as when charging from a deep discharge, as far as the "total number of recharges" that battery pack can withstand before going kaput?

They say the total number of recharge cycles for a given battery is predetermined so, are we shortening the battery's life by recharging when the SoC went down just a little bit and there is plenty of juice for the next trip or two?
Title: Re: Zero SR/F - Newbie Charging Question
Post by: NEW2elec on June 30, 2019, 09:30:31 PM
Well I'll tell you the way it was told to me four years ago when I asked.  :)
A "charge cycle" is from 0% to 100% or a combo of 10 times of 90% to 100%.  Zero estimates about 2500 charge cycles until you have 80% original capacity of the battery.  In theory over 250,000 miles.
 Of course your results may vary and you have a five year battery warrant if things should not go that well.

The other issue of charging a Zero is balancing the cells.  Again on the sub 2020 bikes this is done by the BMS at 100% SOC when charging.  I'm not sure if the SRF can do it at lower SOC or not.
  The range of cell unbalance is on your app listed in mVs  a sub 15mVs is what you want and if your drifting out of that range you should charge it all the way up and let it balance the cells.

You may have some issues along the way but I have two of them and will never have a gas bike at this point.  Enjoy it.  :)
Title: Re: Zero SR/F - Newbie Charging Question
Post by: Auriga on July 01, 2019, 04:19:47 AM
Lithium ion batteries degrade sitting at the top end or low end of the battery. This is usually considered to be ~80-100% and 0-20%. I'd recommend only charging to 80% and recharging once you get to 30% or so. The SR/F and carryover platforms can balance without the charge cord being attached, if left idle for long enough. I'd still charge it to 100% every couple weeks or so to help it along. If you need the range, there's nothing wrong with going to 100%.

I've got data from a population of li/ion powered autonomous robots, and the ones that were lightly used at 100% suffered far worse degradation than those used regularly in the usable range. 

Another reason Zero probably doesn't want you to leave it plugged in for long periods has to do with the chargers. If they fail, and you leave it plugged in for long enough, it can kill the battery. Firmware issues that prevent the bike from fully sleeping could also drain the battery faster than one might expect.
Title: Re: Zero SR/F - Newbie Charging Question
Post by: NetPro on July 01, 2019, 08:52:16 AM
Well I'll tell you the way it was told to me four years ago when I asked.  :)
A "charge cycle" is from 0% to 100% or a combo of 10 times of 90% to 100%.  Zero estimates about 2500 charge cycles until you have 80% original capacity of the battery.  In theory over 250,000 miles.
 Of course your results may vary and you have a five year battery warrant if things should not go that well.

The other issue of charging a Zero is balancing the cells.  Again on the sub 2020 bikes this is done by the BMS at 100% SOC when charging.  I'm not sure if the SRF can do it at lower SOC or not.
  The range of cell unbalance is on your app listed in mVs  a sub 15mVs is what you want and if your drifting out of that range you should charge it all the way up and let it balance the cells.

You may have some issues along the way but I have two of them and will never have a gas bike at this point.  Enjoy it.  :)

This is great news: I am glad to see that the system is computing the level of discharge every time the bike is plugged in and it "knows" when it is just a top off or a full charge as it relates to the number of cycles.
 
Thanks Bro!
Title: Re: Zero SR/F - Newbie Charging Question
Post by: NetPro on July 01, 2019, 09:05:57 AM
Lithium ion batteries degrade sitting at the top end or low end of the battery. This is usually considered to be ~80-100% and 0-20%. I'd recommend only charging to 80% and recharging once you get to 30% or so. The SR/F and carryover platforms can balance without the charge cord being attached, if left idle for long enough. I'd still charge it to 100% every couple weeks or so to help it along. If you need the range, there's nothing wrong with going to 100%.

I've got data from a population of li/ion powered autonomous robots, and the ones that were lightly used at 100% suffered far worse degradation than those used regularly in the usable range. 

Another reason Zero probably doesn't want you to leave it plugged in for long periods has to do with the chargers. If they fail, and you leave it plugged in for long enough, it can kill the battery. Firmware issues that prevent the bike from fully sleeping could also drain the battery faster than one might expect.

Yeah, them lithium batteries are finicky but at least we don't have to worry about memory effect as in years past.
These recommendations are not that hard to follow and I'll stick to them going forward.

Thanks!