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Did Charging Rate Change with V8.0(17.5.28)?

Discussion in 'North America' started by RR Runabout, Feb 6, 2017.

  1. RR Runabout

    RR Runabout Member

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    Did V8.0(17.5.28) software release change the charging rate?

    I have the High Amperage Charger Upgrade.. I noticed an improved MPH charging rate.. I at home I have a 100Amp circuit with the 72 Amp Charger..

    Before the upgrade I was charging at a rate of 35 MPH - I remembered calculating that charge rate was about 1/2 an amp per hour... Today after the upgrade today, I am charging at a 54 MHS or about 3/4 an amp per hour... A 50% improvement.

    Both before and after, same voltage being reported 226V and 72/72 Amps...

    Has anyone experienced it? charging.PNG
     

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  2. RR Runabout

    RR Runabout Member

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    At my cabin, plugged into a 30 Amp dryer outlet with charging amperage set to 28 Amps (yeah a little high) I always pull in about 17 MPH of charge - about 1/2 an Amp per mile hour... I will see this weekend if it charging rate changes...
     
  3. arg

    arg Supporting Member

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    duplicating my answer from the other thread where you posted this:

    You are almost certainly being misled by the fact that the MPH figure is an average over the whole charge.

    55MPH is about right for 72A 230V, and probably this is what you've been getting all along. The current does take a few seconds to ramp up from zero to 72A, so at the very beginning the average is held down by this ramp-up time when the charging was slower. After a few minutes, the ramp-up is only a tiny fraction of the whole and the average number is the same as an instantaneous value.

    Another factor that can make the ramp-up much longer is low temperature: if the battery is very cold, the battery heater will run and charging will be slow (or even not at all in extreme cold). So in this case there could be quite some minutes of slow charging before it gets going at full speed (though it will be showing something smaller than 72/72A while that's going on) - if you then take a look at it just after it has got up to full blast, the average will much less than the current speed, and while it's now charging at fairly constant speed the average will take a long time to catch up.

    The average is even more confusing at the end of the charge (especially at Superchargers) - as the speed tapers off above 90%, and particularly when at 99% it's hardly charging at all, the average will still be dominated by what was going on in the middle of the charge. This can lead to you wasting time sitting there thinking "another 5 mins will give me another 10 miles, so it's worth waiting!" when in fact it gives you almost nothing. Looking at the amps figure gives you a much closer idea of what is going on at any moment.
     
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  4. RR Runabout

    RR Runabout Member

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    Thanks for the response..

    So, I am an electrical engineer. I absolutely understand the asymptotic nature of charging to the battery to peak and almost every time I charge it is to the 80% range.

    I should have stated that prior to the upgrade, every time I sampled the charging remotely or in the car directly, many many times throughout a single charge period and across many charging cycles, I never saw a single sample that was over 35 MPH...

    Something changed and it was not the power at my house...
     
  5. scaesare

    scaesare Well-Known Member

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    Did you actually get that amount of range accumulated? And you had verified the car was reporting [email protected]~240V?

    That rate is almost exactly right for a 48A charge current. It would seem something was reporting wrong. Either:

    -The mileage rate was wrong, and you should have seen more mile accumulate than the reported rate suggested

    or

    - The reported current was incorrect, and your charger was only operating at 48A previously...

    I would assume the former would have been noticeable... and a firmware upgrade could likely address the latter, so I'd bet that was it.
     

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