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[EDoggN]

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?

[Jarrett]

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.

[NEW2elec]

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.

[alko]

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.

[Jarrett]

Zero told me:

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

Not sure what a long period of time is though.

[alko]

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?

[pacificcricket]

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.

[EDoggN]

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.

[Jarrett]

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.

[pacificcricket]

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.

[DonTom]

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

[NEW2elec]

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.

[alko]

Zero recommendation also says keep SOC between 30-60% during long term storage.

[DonTom]

"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

[pacificcricket]

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.