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[DonTom]

When charging my bike it varies between a little over 800 watts to just over 1500 watts, without graphing that over time I can't possibly estimate how much energy has gone into the battery. Of course charging time will give you an idea if capacity is reduced, if comparing it to earlier times, but it can't be used to figure out by how much.

And the time on the display to 100% SOC (ever notice it?) will take that into consideration. Add a charger and you will see the time to 100% decrease on the  display in proportion to charge rate.

My charge rate is the same as ever, but there is only half the battery to charge at that  same (varying) rate. The display only "knows"  about the charge rate, not the battery, so it shows twice the time that it really takes to get to 100% SOC.

IOW, my time to 100% SOC  is programmed for a 6.5 KWH battery that really only has around 3.25 KWHs. The time to charge doesn't "know" my battery will finish the charge in half the time it shows.

-Don-  Auburn, CA

[TheRan]

When charging my bike it varies between a little over 800 watts to just over 1500 watts, without graphing that over time I can't possibly estimate how much energy has gone into the battery. Of course charging time will give you an idea if capacity is reduced, if comparing it to earlier times, but it can't be used to figure out by how much.

And the time on the display to 100% SOC (ever notice it?) will take that into consideration.

How could it? It can't predict the future. It has no way of knowing what the average wattage will be over the charging period. Anyway that's besides the point, which is that the charging rate can vary (and thus the time to charge). If one day my bike average closer to 800 watts and then in a couple months time it averages closer to 1500 watts, just because my bike charged faster doesn't mean the battery capacity has decreased.

[DonTom]

How could it? It can't predict the future. It has no way of knowing what the average wattage will be over the charging period.

It's programmed for the bike, it has no need to read the future. If everything is working right, it's quite accurate. Haven't you ever used it? See how accurate it is on your bike. Mine used to be accurate within a few minutes or so, if not right on the nose. Now it reads double the time it takes to get to 100%.

Go charge your bike and look at it, and report back here how far off it is by using a real clock. Your charge rate makes no difference. Use as many or as little external chargers as you want, the display will know.

I get the feeling you never even knew the Zero display tells you how long the charge should take--at any charge rate.

-Don-  Auburn, CA

[TheRan]

How could it? It can't predict the future. It has no way of knowing what the average wattage will be over the charging period.

It's programmed for the bike, it has no need to read the future. If everything is working right, it's quite accurate. Haven't you ever used it? See how accurate it is on your bike. Mine used to be accurate within a few minutes or so, if not right on the nose. Now it reads double the time it takes to get to 100%.

Go charge your bike and look at it, and report back here how far off it is by using a real clock. Your charge rate makes no difference. Use as many or as little external chargers as you want, the display will know.

I get the feeling you never even knew the Zero display tells you how long the charge should take--at any charge rate.

-Don-  Auburn, CA

I'm well aware that it exists, both on the dash and the app. It's never been that accurate for me, usually it underestimates how long the charge will take.

I don't know for sure how it makes the estimate but it can be one of two ways, it can assume a certain constant charge rate (say 1200w) and not care if it varies or it can take an average wattage reading over a certain amount of time and periodically update the expected charge time. If it uses the first method then using the time estimate on the dash can be an accurate measure of capacity if the bike itself knows the capacity (it has the means to calculate it). If it uses the latter method, which would be the most logical, then the time on the dash is meaningless in determining capacity. In either case actually timing how long it takes to charge is also meaningless because the charge rate isn't constant.

[DonTom]

I'm well aware that it exists, both on the dash and the app. It's never been that accurate for me, usually it underestimates how long the charge will take.

I don't know for sure how it makes the estimate but it can be one of two ways, it can assume a certain constant charge rate (say 1200w) and not care if it varies or it can take an average wattage reading over a certain amount of time and periodically update the expected charge time. If it uses the first method then using the time estimate on the dash can be an accurate measure of capacity if the bike itself knows the capacity (it has the means to calculate it). If it uses the latter method, which would be the most logical, then the time on the dash is meaningless in determining capacity. In either case actually timing how long it takes to charge is also meaningless because the charge rate isn't constant.

The time it shows varies with charge rate almost  instantly. You can see that as you add and remove chargers, even non-Zero  chargers connected a non-stock way. A delay of perhaps a half minute or less to show the new time. I have charged my SR as high as 8.4KW and the MUCH shorter charge  time displayed is still accurate on the bike. My Elcons (5 KW total) go directly to the motor controller. To get to 8.4 KW, I add a couple of Delta Q chargers to the stock input designed for such with Zero's Y cable. I normally use 240 VAC for all my charging.

It's only my DS where it is not accurate because of the bad battery. The range on my SR has not changed much. At least not enough for me to notice. And no noticeable difference in the charge times.  If it says I need to charge for an hour, if I come back to check five minutes early,  it says I have five minutes left. It's very accurate on my SR, unlike my DS.

BTW, the most I ever charged my DS is at 3.4 KW. So I know I never overcharged it.

-Don- Auburn, CA

[TheRan]

I don't know for sure how it makes the estimate but it can be one of two ways, it can assume a certain constant charge rate (say 1200w) and not care if it varies or it can take an average wattage reading over a certain amount of time and periodically update the expected charge time. If it uses the first method then using the time estimate on the dash can be an accurate measure of capacity if the bike itself knows the capacity (it has the means to calculate it). If it uses the latter method, which would be the most logical, then the time on the dash is meaningless in determining capacity. In either case actually timing how long it takes to charge is also meaningless because the charge rate isn't constant.

The time it shows varies with charge rate almost  instantly. You can see that as you add and remove chargers, even non-Zero  chargers connected a non-stock way. A delay of perhaps a half minute or less to show the new time.

-Don- Auburn, CA

So it makes an estimate based on the average wattage over a set period, the second method I mentioned. That's good for getting an accurate estimate if the average stays constant but it must not for me, it must drop over time so the charging rate slows towards the end (it's perhaps particularly high at the beginning, peaking at over 1.5kW for a 1.2kW charger).

Still, even if it is really accurate it's not always going to be consistent and that's the point I'm trying to make.

[Crissa]

Why wouldn't it know the charge rate?  It's what's talking to the chargers.

-Crissa

[DonTom]

So it makes an estimate based on the average wattage over a set period, the second method I mentioned. That's good for getting an accurate estimate if the average stays constant but it must not for me, it must drop over time so the charging rate slows towards the end (it's perhaps particularly high at the beginning, peaking at over 1.5kW for a 1.2kW charger).

Still, even if it is really accurate it's not always going to be consistent and that's the point I'm trying to make.

I think charge time will be reasonably consistent  if the battery itself doesn't change much and the temperature is near normal. Of course the charge rate drops near the end. And likewise, it shows that longer time in the time left to charge.

If yours shows significantly  more time than it takes to charge, have you also noticed a reduction in your average  range?  Perhaps you're starting to have the same problem as with my DS. What size battery is in your Zero? Usually the smaller batteries crap out faster than the ones with more KWHs available as the percentage of load versus KWH is  larger on the smaller batteries.

MY SR with pwr tank  is the same age as my DS and has as much range (and long charge times!) as it did when the bike was new. At least I cannot notice any difference.

-Don-  Auburn, CA

[Richard230]

In the case of my 2018 S with PT, the estimated time to 100% SOC seems quite accurate, after it has been charging for a while and gets settled-in.  When you first plug the charger in it provides a longer time than it will actually take.  But after a while, the time reduces to become quite accurate, almost down to the minute when it will reach 100% SOC.  But once that happens it will require about 10 more minutes more before the green light stops flashing and the charger shuts off.  I closely watch this as I need to pull the charger power plug within 10 minutes of the charger cutting off otherwise the solid green light will remain on and the battery pack will slowly start draining after I pull the power cord. If I don't pull the plug, the green light will remain on (for days) until I turn the ignition on, at which time I will hear two loud clicks, then when I turn the ignition back off, I will hear one click and the green light will finally go off.

As I have said before, I have plugged in a Kill-A-Watt meter and there is no charge tapering on my bike once 100% SOC has been achieved.  As soon as charging ends and the green charging light becomes solid, the power decreases from 1350 watts to 3 watts within a few seconds and will stay at 3 watts until the power cord is disconnected.

[TheRan]

So it makes an estimate based on the average wattage over a set period, the second method I mentioned. That's good for getting an accurate estimate if the average stays constant but it must not for me, it must drop over time so the charging rate slows towards the end (it's perhaps particularly high at the beginning, peaking at over 1.5kW for a 1.2kW charger).

Still, even if it is really accurate it's not always going to be consistent and that's the point I'm trying to make.

I think charge time will be reasonably consistent  if the battery itself doesn't change much and the temperature is near normal. Of course the charge rate drops near the end. And likewise, it shows that longer time in the time left to charge.

If yours shows significantly  more time than it takes to charge, have you also noticed a reduction in your average  range?  Perhaps you're starting to have the same problem as with my DS. What size battery is in your Zero? Usually the smaller batteries crap out faster than the ones with more KWHs available as the percentage of load versus KWH is  larger on the smaller batteries.

MY SR with pwr tank  is the same age as my DS and has as much range (and long charge times!) as it did when the bike was new. At least I cannot notice any difference.

-Don-  Auburn, CA

Perhaps there's something up with my charger, but as I've said the charge rate varies from 800 to 1500 watts. If it spends more time at 1500 it will charge faster, if it spends more time closer to 800 it will charge slower. The estimated time isn't wildly inaccurate nor does the charge time vary drastically from what I would expect (it tends to average out to around 1200/1300 watts, around 2.5 hours for half a charge, etc.) but the fact that it doesn't charge at a constant and steady rate means that it could vary.

When you're charger your bike, does the charge rate stay at a constant wattage as shown by the app? Is that wattage always the same?

[NEW2elec]

My app shows the amps and watts of course jump around all over the place.  My Kill a Watt meter shows it being much steadier.

[DonTom]

My app shows the amps and watts of course jump around all over the place.  My Kill a Watt meter shows it being much steadier.

I have noticed that also, but it's only with the OBC. If you run ONLY Delta- Q-Chargers or other chargers and keep the OBC off, it is rock steady using the same app. And like you say, even the OBC is rock steady on a kill-a-Watt meter on the AC side as it is jumping all over on the DC side.

If you run both, the OBC with the Delta Q chargers, it is still a jumpy output.

I was wondering if it had something to do with cell balancing, but I think all that is done only near the end of the charge. This jumpiness is at any percentage of SOC when the OBC is on.

I wish I knew why, but I could not find a clue.

In fact, I have asked about that here more than a year ago. Seems nobody knows the reason why it's jumpy on the app only when the OBC is on--yet steady on the AC side. And steady with running any chargers without the OBC using the same app.

So I will ask again . . .

Anybody here have a clue why?

-Don-  Auburn, CA

[Richard230]

No clues here.   

[DonTom]

When you're charger your bike, does the charge rate stay at a constant wattage as shown by the app? Is that wattage always the same?

I have not looked at the app while charging for quite a while, so I cannot be sure what the app says but I assume it will show less wattage at the last 5% or so of SOC

What I do remember is the jumpiness in watts on the app whenever the on-board charger is used and it being rock steady when any other external charger is used. And how the AC current  is rock steady as it is jumping on the app.  I remember all that because I found it to be very unusual and have no clue what is really happening. BTW, that was why I put a Killowatt meter on the AC side. Since it was rock stable, it only added to the confusion of what causes the jumpiness in the app only when the  OBC is used.

-Don-  Auburn, CA

[togo]

> ... This jumpiness is at any percentage of SOC when the OBC is on.
> I wish I knew why, but I could not find a clue.

Even when cold?  I'm thinking it could be thermal...?