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[NervEasy]

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?

[nnelson65]

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?

[NervEasy]

Theh so weird, thanks!

[NoMoreIdeas]

Same thing happens on mine. I thought it was weird at first and then just got used to it.

[DonTom]

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

[BrianTRice@gmail.com]

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.

[DonTom]

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

[Richard230]

I saw a "71%" SOC yesterday. 

[domingo3]

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? 

[BrianTRice@gmail.com]

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.

[Curt]

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.

[DonTom]

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

[BrianTRice@gmail.com]

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.

[DonTom]

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 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

[BrianTRice@gmail.com]

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.