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[kcoplan]

Putting miles on my 2012 Zero S . . . Slowly.

Two questions for more experienced owners -

1) how accurate is the speedometer at highway speeds?  Although the speed flasher in the MacBook zone seems to confirm the 22 mph reading on my speedometer,  75 mph on the speedometer on the highway does not feel like a true 75 mph given the traffic passing me.  Anyone confirm the speed calibration?

2) how accurate is the battery bar indicator?  Can I count on six bars really being just as much range left as I have already used up.  I want to test the limits of how far I can ride, without having to push the bike home.  If I ride out for six bars, can I count on riding back without boinking the battery pack (assuming that I am not doing more speed or climbing on the way back)?  So far, I have dared to ride out 5 bars worth on the parkway and return on back roads, leaving 4 bars remaining, so I am sure I can go a little farther . . .

Thanks in advance for advice.

- Karl

[protomech]

My speedometer reads about 4% high. YMMV.

Harlan posted instructions for recalibrating the speedometer here, though I have not yet tried them.

There are 11 visible bars on the "fuel" gauge. The first bar often seems like it has 2/3 the energy of the other bars (probably due to the charge terminating around 97-99% SOC); otherwise the bars feel very linear, probably within 10% of each other.

When the final bar disappears, the battery is at approximately 15% SOC. If discharged to 0% 0% SOC then it effectively has an extra 1.5 - 2.0 invisible capacity bars. I view these as an emergency reserve and try to avoid regularly tapping into it; the battery pack will probably live longer if it is not fully discharged, and as it ages the battery may increasingly hit its lower-voltage cutoff well before 0% SOC.

You will probably be well-served to determine the margin of error on both of these parameters for yourself; eg measure a route via GPS then compare to bike odometer, and record miles at a certain speed for each bar, then do a loop near to home until the battery cuts out. Or as near as you care to take it.

[Doctorbass]

My speedometer reads about 4% high. YMMV.

Harlan posted instructions for recalibrating the speedometer here, though I have not yet tried them.

There are 11 visible bars on the "fuel" gauge. The first bar often seems like it has 2/3 the energy of the other bars (probably due to the charge terminating around 97-99% SOC); otherwise the bars feel very linear, probably within 10% of each other.

When the final bar disappears, the battery is at approximately 15% SOC. If discharged to 0% 0% SOC then it effectively has an extra 1.5 - 2.0 invisible capacity bars. I view these as an emergency reserve and try to avoid regularly tapping into it; the battery pack will probably live longer if it is not fully discharged, and as it ages the battery may increasingly hit its lower-voltage cutoff well before 0% SOC.

You will probably be well-served to determine the margin of error on both of these parameters for yourself; eg measure a route via GPS then compare to bike odometer, and record miles at a certain speed for each bar, then do a loop near to home until the battery cuts out. Or as near as you care to take it.

As for the speedo calibration, do you know if there is a way to recalibrate the "fuel" gauge bar?.. I replaced my BMS on my DS 2011 with a nre upgraded from zero but the fuel gauge is off calibration ... the last bar dissapear and i still have 35Ah in the battery ( on that 70 ah full pack).. I installed a cycle analyst device that count the Ah with a shunt...)

any help to the fuel  gauge  recalibrated? or is it software?.. if so what is the way to reprogram it with the OBDII port with the Can/Bus...

Thanks!

Doc

[kcoplan]

Thanks for all the advice - went on a 45 mile ride today and got home with two bars flashing at me.  Not as interested in miles, per se, as with "where can I go for a ride and still get home to charge?". Miles will vary depending on highway versus back roads and hills versus flats.

The good news is now I know I can ride from my house up to Harriman State park via back roads, ride some of the park roads up there, come back on the Palisades Parkway, and still have two bars to spare.  That's all I really need to know, for now!

- Karl

[iJustride]

My speedometer reads about 4% high. YMMV.

Harlan posted instructions for recalibrating the speedometer here, though I have not yet tried them.

Anyone know the input value needed to provide an accurate speedo reading on a stock bike? Mine is also around 4% high.

[ColoPaul]

Hi and Welcome IJustride

My stock speedo value was "832";  I was also seeing about 4% high like protomech.
To adjust, I took 832 * 0.96 = 798;  I entered "798" and now it's pretty close.

[iJustride]

Hi and Welcome IJustride

My stock speedo value was "832";  I was also seeing about 4% high like protomech.
To adjust, I took 832 * 0.96 = 798;  I entered "798" and now it's pretty close.

Thank you!
Makes sense now, at first glance I thought the math was more complicated than that.

[paul]

The battery SOC estimation (aka "fuel gauge") should improve slightly over the first few packs you burn through as the BMS self-calibrates itself.

[NoiseBoy]

Its worth mentioning that the speedo has to read high by law (at least in Europe) to prevent drivers from blaming the vehicle for speeding fines.  4% is actually pretty accurate as most cars are nearer 10% over.  Probably an idea to have it reading a little high so you aren't playing chicken with the radar guns.

[paul]

All precision measurements have a margin of uncertainty that is unavoidable in reality.  Especially in a high volume scenario like a motorcycle production line, it's unreasonable to expect each and every speedometer to be calibrated within anything better than, say, 5-10% of its true value (value is guesstimate - I don't know actual tolerance offhand).

It's not that law requires it to read high - it's that reading the speed too high is not as bad as reading it too low in the eyes of various regulatory bodies...

[protomech]

I'm glad that the LVC precision sensor is not 5% too low (risking battery safety) or 5% high (slightly reducing range). Or that the charger's voltage sensor is not set 5% too high (risking battery safety on charge termination) or 5% too low (slightly reducing range).

[Doctorbass]

I'm glad that the LVC precision sensor is not 5% too low (risking battery safety) or 5% high (slightly reducing range). Or that the charger's voltage sensor is not set 5% too high (risking battery safety on charge termination) or 5% too low (slightly reducing range).

Yeah it seem pretty accurate.. I have measure dthat the LVC of my zero 2011 is at 3.00V parallel group. wich is the recommanded for lithium ( non phosphate) cells.. but the molicells are 2.5V if i remember correctly.. but i guess keeping these 500mV higher LVC reduce the risk of unbalance the pack sicn ethe RI variation is more affected on both end of the cahrge discharge curve.

Doc

[ColoPaul]

All precision measurements have a margin of uncertainty that is unavoidable in reality.  Especially in a high volume scenario like a motorcycle production line, it's unreasonable to expect each and every speedometer to be calibrated within anything better than, say, 5-10% of its true value (value is guesstimate - I don't know actual tolerance offhand).

I would bet $10 that Zero intentionally sets the speedo's 5%+/-1% high.  Range is key for an emoto; what cheaper easier way to get 5% more range?  Also the side effect of making the bike 'feel' a little faster.

[Richard230]

While my speedometer also reads about 4% high (I have a couple of BMWs that read 8% fast), I think the bike's odometer is pretty accurate as it seems to agree with the odometer of my car when traveling over the identical route.

[amahoser]

 
I would bet $10 that Zero intentionally sets the speedo's 5%+/-1% high.  Range is key for an emoto; what cheaper easier way to get 5% more range?  Also th
e side effect of making the bike 'feel' a little faster.
 

I'll take that bet. You are correct that Zero intentionally set the Speedo high. But the reason isn't a conspiracy. It is federally mandated that a manufacturer cannot have a speedometer that displays a speed lower than actual. Higher than actual is perfectly acceptable but lower is illegal. So most manufacturers set a Speedo 5 to 10% higher for a safety margin. Most gas cars and  motorcycles display higher than actual.

Jose Soriano