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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: NervEasy on January 18, 2020, 03:38:28 AM

Title: SoC 82% to 80%
Post by: NervEasy on January 18, 2020, 03:38:28 AM
Hi,

Quick question. My SoC always jumps from 82 to 80 when driving. 81 just doesn’t happen.
Does anybody else noticed it on their Zero?

Title: Re: SoC 82% to 80%
Post by: nnelson65 on January 18, 2020, 04:02:10 AM
Yep, it's a known thing... the display skips 81,61,41,21, and 1.

Hi,

Quick question. My SoC always jumps from 82 to 80 when driving. 81 just doesn’t happen.
Does anybody else noticed it on their Zero?
Title: Re: SoC 82% to 80%
Post by: NervEasy on January 18, 2020, 12:59:22 PM
Theh so weird, thanks!
Title: Re: SoC 82% to 80%
Post by: NoMoreIdeas on January 19, 2020, 01:32:17 AM
Same thing happens on mine. I thought it was weird at first and then just got used to it.
Title: Re: SoC 82% to 80%
Post by: DonTom on January 19, 2020, 10:43:27 AM
Hi,

Quick question. My SoC always jumps from 82 to 80 when driving. 81 just doesn’t happen.
Does anybody else noticed it on their Zero?
My Zero DS SOC  will never display 41.   42 to 40, a little regen will put it back from 40 to 42. I have never seen it display a 41 ever.

I really never thought anything of it. I never expect anything digital to work perfectly all the time. But most of the bugs I can live with.

-Don-  Auburn, CA
Title: Re: SoC 82% to 80%
Post by: BrianTRice@gmail.com on January 22, 2020, 07:10:23 AM
I remembered to update the unofficial wiki for this:
https://zeromanual.com/wiki/Gen2/Instrument_Cluster/Indications#SoC

Of course, that's a pretty small note, but I don't have a better place for it.
Title: Re: SoC 82% to 80%
Post by: DonTom on January 22, 2020, 07:20:58 AM
Yep,w it's a known thing... the display skips 81,61,41,21, and 1.
I have only noticed the lack of the 41.  I must not have noticed the others. Interesting how it's every 20 SOC points.

Now i will be looking for the other three. I won't be looking for the plain "1" .  At least I hope not :).

-Don-  Auburn, CA
Title: Re: SoC 82% to 80%
Post by: Richard230 on January 22, 2020, 08:49:03 PM
I saw a "71%" SOC yesterday. 
Title: Re: SoC 82% to 80%
Post by: domingo3 on January 23, 2020, 07:01:49 AM
I think I read somewhere that 0% is really 5% as an explanation for being able to go on with 0 SOC for a while.  Doesn't seem to make sense since where you program 0% is kinda nominal anyway.  I had the passing thought that maybe someone programmed it to skip those 5 (81,61,41,21,1) numbers to give you the 5% at the end, but that seems like a ridiculous idea.

P.S.  Does SRF have this same idiosyncrasy? 
Title: Re: SoC 82% to 80%
Post by: BrianTRice@gmail.com on January 23, 2020, 07:13:03 AM
0% is not always "really 5%". In the best case, there is a reserve, but that is a soft assurance that can vary with cell balance etc.

I think the thing is that SoC on the dash is encoded in an idiosyncratic way, so that those values that don't display on the dash do show up on the app.
Title: Re: SoC 82% to 80%
Post by: Curt on January 23, 2020, 04:54:08 PM
I think I read somewhere that 0% is really 5% as an explanation for being able to go on with 0 SOC for a while.  Doesn't seem to make sense since where you program 0% is kinda nominal anyway.  I had the passing thought that maybe someone programmed it to skip those 5 (81,61,41,21,1) numbers to give you the 5% at the end, but that seems like a ridiculous idea.

This topic came up before and I posted something about it, but now I can't find it in searches.

Basically, I think you're correct that Zero extends a range [0, 95) to a scale of 1-100%, and by the pigeon-hole principle, exactly 5 values must be skipped.

My proof of concept test was the following code:

for i in range(95):
    print(i * 100 / 95 + 2)

This prints the numbers from 1 to 100 -- skipping 1, 21, 41, 61, and 81.
Title: Re: SoC 82% to 80%
Post by: DonTom on January 23, 2020, 09:49:32 PM
This prints the numbers from 1 to 100 -- skipping 1, 21, 41, 61, and 81.
If that's the case, I would think skipping the "1" would be a very poor choice.

-Don-  Auburn, CA
Title: Re: SoC 82% to 80%
Post by: BrianTRice@gmail.com on January 23, 2020, 10:18:55 PM
Summarizing battery state as a two digit percentage was a poor choice in 2014 when they introduced it.

Honestly, the 11 bars used on the Koso dash in 2013 conveyed information in a much more honest way, by not over implying precision, and giving the algorithm wiggle room for adjustments without bothering the rider. Sure, 11 bars were somewhat too few, and debatably 50 bars would be fine with blinking to create grey fuzziness when there’s a risk of imbalance causing early range loss.

It is instructive that we still have the custom dash hack for SDS bikes. I wish I had one to mess with.

Anyway, I’ll see whether I can wrap this up into yet another note in the unofficial manual.
Title: Re: SoC 82% to 80%
Post by: DonTom on January 23, 2020, 11:18:46 PM
Summarizing battery state as a two digit percentage was a poor choice in 2014 when they introduced it.

Honestly, the 11 bars used on the Koso dash in 2013 conveyed information in a much more honest way, by not over implying precision, and giving the algorithm wiggle room for adjustments without bothering the rider. Sure, 11 bars were somewhat too few, and debatably 50 bars would be fine with blinking to create grey fuzziness when there’s a risk of imbalance causing early range loss.

It is instructive that we still have the custom dash hack for SDS bikes. I wish I had one to mess with.

Anyway, I’ll see whether I can wrap this up into yet another note in the unofficial manual.
I have considered installing a small voltmeter on the bike, if I could find a good place to mount such. I think an anaolog voltmeter (https://www.ebay.com/itm/Crompton-Instruments-Analog-Panel-Mount-DC-Voltmeter-0-200-Volts-Meter-/133126131559) would be best, with a resistor in series at the bike's external charger connector for  safety.

Has anybody here done such?

-Don-  Auburn, CA
Title: Re: SoC 82% to 80%
Post by: BrianTRice@gmail.com on January 24, 2020, 03:26:22 AM
Zero bikes already have a voltmeter on the bus, and there are two Android apps that help read and one of them charts it by the second and down to the millivolt.

The Metrics app shows very clearly that voltage depends so much on throttle position while riding that it cannot easily be used to estimate SoC.

I’ve actually considered reverse estimating throttle position from this graph, because of how it dominates the gradual downward trend as capacity is used.
Title: Re: SoC 82% to 80%
Post by: DonTom on January 24, 2020, 07:36:40 AM
Zero bikes already have a voltmeter on the bus, and there are two Android apps that help read and one of them charts it by the second and down to the millivolt.
But I would prefer it to be true analog.

I think I already have the app, if "Zero Voltage (https://play.google.com/store/apps/details?id=com.bitshape.zero_voltage&hl=en_US)" is one of them.


-Don- Auburn, CA
Title: Re: SoC 82% to 80%
Post by: BrianTRice@gmail.com on January 24, 2020, 11:45:25 AM
Zero bikes already have a voltmeter on the bus, and there are two Android apps that help read and one of them charts it by the second and down to the millivolt.
But I would prefer it to be true analog.

okay boomer

I think I already have the app, if "Zero Voltage (https://play.google.com/store/apps/details?id=com.bitshape.zero_voltage&hl=en_US)" is one of them.

"Metrics for Zero Motorcycles" is what I'm primarily referring to: https://play.google.com/store/apps/details?id=com.mc.zero&hl=en_US
Title: Re: SoC 82% to 80%
Post by: DonTom on January 24, 2020, 11:52:51 AM
"Metrics for Zero Motorcycles" is what I'm primarily referring to: https://play.google.com/store/apps/details?id=com.mc.zero&hl=en_US
I like that  one! I didn't know it existed. I will go with it, thanks!

-Don-  Auburn, CA
Title: Re: SoC 82% to 80%
Post by: DonTom on January 25, 2020, 04:03:28 AM
Well, here is why I have learned to never assume anything until it is all tested. I got a real surprise after I rode my Zero DS down to 57% SOC today. The battery voltage is exactly 106.0 VDC measured directly on the Delta Q. connector.

106.0 VDC according the charge in the unofficial guide (https://zeromanual.com/wiki/State_of_Charge) is normally around 73% SOC. This means my battery is fine, but my SOC % reads flaky!

I think the change happened right after I got the last FW update, but I didn't notice the major change in what I thought was range until well after.

But this makes me wonder what range I will have left at 0 SOC. I figure quite a bit, if the   charge vs. SOC is reasonably accurate here. (https://zeromanual.com/wiki/State_of_Charge)

Whops, in more checking, I find a BIG contradiction here (https://zeromanual.com/wiki/SoC_per_Voltage), which means my bike SOC is okay and the battery is flaky.

Now I  notice a "must fix" in the longer chart, so now I do have to assume the battery.

Brian, any comments?

-Don-  Auburn, CA
Title: Re: SoC 82% to 80%
Post by: domingo3 on January 25, 2020, 07:04:31 AM
Well, here is why I have learned to never assume anything until it is all tested. I got a real surprise after I rode my Zero DS down to 57% SOC today. The battery voltage is exactly 106.0 VDC measured directly on the Delta Q. connector.

106.0 VDC according the charge in the unofficial guide (https://zeromanual.com/wiki/State_of_Charge) is normally around 73% SOC. This means my battery is fine, but my SOC % reads flaky!

I think the change happened right after I got the last FW update, but I didn't notice the major change in what I thought was range until well after.

But this makes me wonder what range I will have left at 0 SOC. I figure quite a bit, if the   charge vs. SOC is reasonably accurate here. (https://zeromanual.com/wiki/State_of_Charge)

Whops, in more checking, I find a BIG contradiction here (https://zeromanual.com/wiki/SoC_per_Voltage), which means my bike SOC is okay and the battery is flaky.

Now I  notice a "must fix" in the longer chart, so now I do have to assume the battery.

Brian, any comments?

-Don-  Auburn, CA

What leads you to say that your battery is flaky?   I feel like I missed something.
Title: Re: SoC 82% to 80%
Post by: DonTom on January 25, 2020, 10:09:38 AM
Quote from: domingo3 link=topic=9767.msg87236#msg87236
What leads you to say that your battery is flaky?   I feel like I missed something.
Today, I started with my SOC at 100% (above 115 volts). I rode it for exactly 14.8 miles mostly at around 35 MPH. Some slower (10 MPH), some a bit faster (50 MPH). That took 43% ( SOC  indicated is 57% of my SOC or down to 106.0 volts).

I am getting around 0.34418 miles per 1 SOC average in mostly easy slow riding. My SOC will even go down faster with a few more miles.

On the freeway, I would not be able to go 20 miles at 65 MPH. Perhaps not even 15 miles. I would not even chance ten miles at 65 MPH.

It's a 6.5 KWH battery. Temp was  a little above 50F. today.

Spec for full range on this bike is:

City=74 miles
Highway=35 miles
Combined=47 miles

-Don-  Auburn, CA
Title: Re: SoC 82% to 80%
Post by: BrianTRice@gmail.com on January 26, 2020, 06:57:22 AM
The SoC to voltage curve is for at-rest conditions and is only the most vague guide because it may even vary by model year.

Also, Zero computes SoC in a proprietary way that I am not privy to.

I am really tiring of DonTom hijacking threads to talk about this. This thread is about SoC display discontinuity.

Make your own thread.
Title: Re: SoC 82% to 80%
Post by: Crissa on January 26, 2020, 08:56:08 AM
Yeah, Don, can you collect all these observations into one place?

It'll be useful as other bikes age and start having battery symptoms, too.

-Crissa
Title: Re: SoC 82% to 80%
Post by: togo on January 28, 2020, 07:01:32 AM

> I have considered installing a small voltmeter on the bike, if I could find a good place to mount such. I think an anaolog voltmeter (https://www.ebay.com/itm/Crompton-Instruments-Analog-Panel-Mount-DC-Voltmeter-0-200-Volts-Meter-/133126131559) would be best, with a resistor in series at the bike's external charger connector for  safety.

> Has anybody here done such?

Yes, this one:

https://www.amazon.com/gp/aw/d/B01DW8AIFI/ref=ppx_yo_mob_b_track_package_o0_img?ie=UTF8&psc=1

Fuses at battery end, both wires, and thin wires, since it's just a little bit of current.  I used ring terminals to the controller, under the seat. Doubles as an indication contractor is on.