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[DonTom]

Say an 10 KWH battery gets old, and only has 5 KWH capacity left. What will the new charge times be? Will it stay the same or be longer or shorter?

Same question when a new  battery is warm compared to cold. Do the charge times change when charged at the same rate?

-Don-  Payson, AZ (RV)

[Crissa]

Varies by the charging system.  Some don't lose charging time, but most slowly charge faster as the battery stops being quite as elastic.

But my Zero seems to have the same charging time as new, so I don't know how Zeros react.

-Crissa

[DonTom]

Varies by the charging system.  Some don't lose charging time, but most slowly charge faster as the battery stops being quite as elastic.

But my Zero seems to have the same charging time as new, so I don't know how Zeros react.

-Crissa

The reason I am asking is that my 2017 Zero DS 6.5 seems to be charging faster but is also draining the battery faster for the distance used.

I also notice larger gains in SOC from regen., as well as a faster loss.  I see it increase  the SOC a lot more as I ride down hill and use more SOC when going uphill than before. A noticeable difference.

I know the SOC is not an accurate indicator. Not only that, I think the way the SOC works  has changed with the last FW update.

But that made me think about asking the questions about charge times when the capacity decreases from either age or cold. IOW, if the time required at the same charge rate is less than more (or the same) as the KWHs decrease from cold or age.

It will be getting cold here next week, highs in the 40's and lows on the 20's. I expect that to make a 20% or so drop in range, but I wondered what it would do to charge times, if anything.


-Don-  Payson, AZ

[Crissa]

Yes, a battery has two basic dimensions of voltage and amp-hours.  As it ages, the two things are slowly eroded.  If you're losing amp-hours, that's the width of your battery.  That's the electrodes losing surface.

The other thing you can lose is voltage - and that's the only real way to measure a battery.  You can't actually measure Ah directly without discharging the battery.  That's why SoC is such an estimate.  If you lose voltage, you'll get shallower charges.  Those 'whiskers' they talk about.

Of course, I don't know the numbers here.  Nor do I know which one does which and that often varies by minute battery pack configurations.

Sounds like your batter is in fact wearing out, how many charge cycles has it gone through?

-Crissa

[DonTom]

Sounds like your batter is in fact wearing out, how many charge cycles has it gone through?Crissa

It gets used a lot, and sometimes gets recharged twice or three time in a day.  For an example, I use the bike a lot to go between my main house in Reno and my other in Cold Springs Valley (18 miles NE of Reno). I charge at both places and when I get back, I may charge again to go elsewhere.

But to get a real good idea if my range has decreased, I will have to wait for a warm summer and calm day and make the same trip.

But that really wasn't why I was asking, I was just curious, I am not too concerned about the range of my 2017 Zero DS ZF 6.5 as long as it has the range necessary for the way I use the bike. To go between those two houses and also to get things while on this RV trip.

-Don-  Payson, AZ

[Crissa]

If we're talking about a 10% difference in time, that could even be input voltage variation.

There's just so many things which go into charge times.

[TheRan]

Assuming the charging rate stays the same, which I think it should (I suppose the pack may heat up more, possibly depending on the battery chemistry), then the charge time will decrease proportionally to the capacity. When the capacity decreases due to "wear" part of the battery becomes non-functional, the chemical reaction that takes place in that part stops working for both charging and discharging.

Of course there can be other factors at play, as Crissa said charging current could be varying, temperature, riding habits, increases in rolling resistance from worn and unlubricated bearings, tyres losing pressure, etc., but if it's a large and consistent difference you're noticing and you know those other factors haven't changed much then the battery losing capacity does seem like a likely cause.

[DonTom]

When the capacity decreases due to "wear" part of the battery becomes non-functional, the chemical reaction that takes place in that part stops working for both charging and discharging.

" but if it's a large and consistent difference you're noticing and you know those other factors haven't changed much then the battery losing capacity does seem like a likely cause."

Your first part above seems to be saying the charge time will increase as the battery kHW decreases from "wear" even though there is lower capacity.

Your second paragraph seems to indicate the opposite. Remember, it seems to both charge as well as discharge faster these days as if i were a new battery of  a lower capacity (which it isn't). Not only are the charge times a lot faster than the screen says it should take, I also notice the difference with regen where I gain more SOC then ever going downhill and us it up faster than usual on level ground or when going uphill. Sometime I get an increase of 3 or four SOC points just by going down hill for a little while.

It could be a difference only in my SOC indication since my last FW update. Perhaps my range has not changed--hard to say.  Perhaps  they made the SOC more sensitive so you can see the regen gain on the SOC.

I really cannot be sure if my range has really reduced unless I ride it far enough to get dangerously low. And I am too chicken to do such out here.

-Don-  Payson, AZ (RV)

[Crissa]

If the wear and tear on the electrolytes is even, yes, it will act like a lesser battery.

Sometimes that means the battery heats up more, wasting energy that it would otherwise produce.  Sometimes that means just being quicker to charge and discharge.

Battery aging is not entirely consistent, that's all.

-Crissa

[Richard230]

In the case of my 2018 S with PT, according to my Kill A Watt meter, when the battery pack is low, the charging rate is relatively slow, but then it ramps up as the SOC nears 100%.  When it reaches 100% the charging rate has increased to 1450 watts, until the charger shuts down suddenly. The charging current from the wall then drops to 9 watts for a few minutes and then to 3 watts, where it will stay until the power is disconnected.

I suppose that if you wanted to check the condition of your battery pack, you could run it down to 00% SOC, plug in a Kill A Watt meter and check the total power consumed when the charging system cuts off.  You could do this every year or so to see if anything has changed.  Interesting, but running the pack empty close enough to home to recharge would be no fun for me. And then there is that pesky 10 miles or so available for when the SOC display reads 00%.  Personally, knowing that information just doesn't seem worth the trouble. 

It is too bad that the Zero app no longer displays available kWh like it used to do for my 2014 S, before that feature was eliminated by Zero during one of their app updates. However, I was not surprised to see that information gone as it did show a slight reduction in pack capacity over time.  Probably not something that Zero wanted its customers to ask about or discuss on owner forums.   

[Crissa]

Being as I live up a steeper than 10% grad, coming back with single-digit charge is stressful enough for me.  Even with two people, it's pretty hard to push let alone up the grade!

They couldn't actually know the KWh remaining, which is probably why they eliminated it.  The information should be in the logs, though, as it keeps running tallies of consumption for range estimation.

-Crissa

[Richard230]

Being as I live up a steeper than 10% grad, coming back with single-digit charge is stressful enough for me.  Even with two people, it's pretty hard to push let alone up the grade!

They couldn't actually know the KWh remaining, which is probably why they eliminated it.  The information should be in the logs, though, as it keeps running tallies of consumption for range estimation.

-Crissa

Well, the app provided the kWh capacity of the battery pack remaining to a hundredth of a kWh.     Apparently they had some system for guessing the power left in the pack. It seemed to correspond closely to my Kill A Watt meter when recharging my 2014 S.

[TheRan]

When the capacity decreases due to "wear" part of the battery becomes non-functional, the chemical reaction that takes place in that part stops working for both charging and discharging.

" but if it's a large and consistent difference you're noticing and you know those other factors haven't changed much then the battery losing capacity does seem like a likely cause."

Your first part above seems to be saying the charge time will increase as the battery kHW decreases from "wear" even though there is lower capacity.

Then you're misreading my post. I said the charge time decreases proportionally to the capacity decrease. Less capacity, less time to charge.

Regarding the inaccurate charging estimate from the screen, perhaps the software is assuming the battery has its original capacity. If your charging current is fairly consistent you can work backwards and see what it thinks the capacity is, and by timing how long it actually takes (or using a Kill-a-watt as someone else mentioned) we can see what the actual capacity is.