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I always wondered how low the battery can go before the car shuts down. A few times it has gone down to below 10 miles but this time hit my personal safety limit
A couple of days ago I almost got stranded on the road

These are the events

Sunday, I drove over 220 miles on the way back home

  • 4 miles from the house the GOM had 8 miles
    • Driving on the highway
    • A/C on
  • 1.7 miles from the house amber warning that the car was going into power safe mode
  • All unnecessary electronics turn off (A/C, displays, etc)
  • Car power reduced. Cars slows downs significantly (let somehow hit the brakes)
  • GOM 0 miles % battery 0%
  • Luckily, I was about to get off the highway towards my house

  • 1.3 miles from house
    • Driving in local residential streets
    • Red warning asking me to pull to the side safely as the car is going to shut down
I decided to continue driving as I was driving on residential area and only had 1.3 miles left to go

I got home plugged in the car and had drink…..

My conclusion: Have a minimum of 10 miles on the GOM to make it safely home
 

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2019 FE Photon Red
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.... I got home plugged in the car and had drink…..

My conclusion: Have a minimum of 10 miles on the GOM to make it safely home
What do you mean? You made it home! 🙂

Push the limit. Next time go around the block one more time before pulling into your driveway.
 

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  • 4 miles from the house the GOM had 8 miles
    • Driving on the highway
    • A/C on
  • 1.7 miles from the house amber warning that the car was going into power safe mode
    • GOM 0 miles % battery 0%
With only 8 miles left on the GOM, I would have turn off the A/C myself a long time ago... :)
At what speed were you cruising on the highway with only 8 miles left ?
That sudden drop at low battery stage, wasn't it exactly what Bjorn in Norway experimented in one of his latest video on the IPace ?
 

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2019 I-Pace HSE - Borasco Grey
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At the bottom is a link to a post I made on the subject a few months ago. The bottom line was I started wondering I was going to make it home the last few miles. Starting with 21 GoM miles, the car burned through 16 GoM miles over the 10 mile drive home even while in lower power modes.

SOC range calculation vs. odometer info...
 

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It is better to rely on the SOC rather than the estimated range, particularly near the bottom of the "tank". The algorithm that calculates the range may have an offset (so not completely proportional) and that remainder at the end might be an underestimate as opposed to an over estimate. I had an occasion where I had, if I recall, a 25km buffer, but that disappeared over the last 30km. With 20km left to go and the GOM at 45, it instantly went to 25!. I went to low power mode and drove carefully and got to the planned fast charger (Whole foods parking lot) with 12 left on the GOM and as I pulled into the lot, the last 12 disappeared to 0 and the car threatened to shut down. I managed to coast to the charge spot, but my knuckles were white. I was not watching the SOC (I was logging data to calculate bat capacity) and learned the lesson.
 

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This has happened to me twice, far away from home...

3955


Both times involved non-working level 3 chargers that I was counting on to use with around 15-20% left. I had to limp my way to a level 2 charger and I arrived with 1%! Scary times and super frustrating to have to wait so long at the level 2 charger to charge enough to reach my destinations.
 

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A recent video said the I-Pace went 20 more miles than the GOM said, before it went dead. ?
They were driving slow in a parking i believe when if hit zero SOC
 

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I noodled my first I-Pace's battery down to below zero twice. First time was a naive attempt, I had 7 miles on the GoM and some 5% SoC (which doesn't make sense, I know) and so I went on a 5 mile loop only to find myself going down to alarm bells 2 miles from home. I did make it home though. Next time I decided to drive around my block a bunch of times to see how low it could go. I did about 3 miles on vapors before I chickened out. There's an old thread on it but I can't find it. I'm not going to do it with my new kitty because it's just not good for it. (I had too much trust in JLR's engineering early on.)

Perhaps the GoM and SoC estimates have gotten more accurate with recent software updates but I still don't trust the numbers on the low end. For example (Geek Alert!):
A linear fit of the charging profile from OBD data (dominated by the linear range which happens between ~10% and 98% SoC) indicates that 0% SoC is at negative 2kWh, which is clearly nonsensical. But batteries don't behave linearly at the extremes of capacity (low or high end) and so things go a little haywire. Enter the API (WattCat's numbers). The software "bends the curves" because the engineers make empirical adjustments in their models at the extremes because the extremes are so unpredictable. Which leads to 5% at 7kWh or Nyland's "oops it dropped from 5 miles to 2 miles in an instant."
 

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My car made it home showing 1 mile remaining on the GOM.

I assume at 10 miles it could literally shut down at any time. Has anyone continued to drive with ZERO miles? How far?

Once in my RAV4-EV I coasted a quarter mile after shut down to get to a parking lot with a charging station. I had learned not to turn the vehicle off as it will still coast in neutral running on the 12v battery. Once you turn it off and go to park it you are not moving until charged or towed. I had to push it back about 10 feet to get on the charger then turned it off.
 

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Over the course of my ownership (>20k miles in 18 months), I've run SoC down to 1%-2% several times, mostly testing near home, but a couple times unintentionally due to 'down' chargers, excessive highway speed cutting into range, unexpected side trips on a planned long journey, etc. Doing so has made me much less anxious in "under 10% SoC" situations, since I know how the car will perform. The key is to activate low power mode as soon as you sense you're in a tight range situation; don't wait for the car to engage it on its own at the last minute. Also drop your highway speed, even 5 mph can make a difference when every mile counts. As a last resort, I've even toggled AC on and off (leaving the fan on 1 or 2) to reduce power consumption. Good to learn where all the DCFC stations are in your metro area, too, as well as number of cords and typical availability. I can definitely attest to the fact that range anxiety diminishes significantly with duration of ownership.
 

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I noodled my first I-Pace's battery down to below zero twice. First time was a naive attempt, I had 7 miles on the GoM and some 5% SoC (which doesn't make sense, I know) and so I went on a 5 mile loop only to find myself going down to alarm bells 2 miles from home. I did make it home though. Next time I decided to drive around my block a bunch of times to see how low it could go. I did about 3 miles on vapors before I chickened out. There's an old thread on it but I can't find it. I'm not going to do it with my new kitty because it's just not good for it. (I had too much trust in JLR's engineering early on.)

Perhaps the GoM and SoC estimates have gotten more accurate with recent software updates but I still don't trust the numbers on the low end. For example (Geek Alert!):
A linear fit of the charging profile from OBD data (dominated by the linear range which happens between ~10% and 98% SoC) indicates that 0% SoC is at negative 2kWh, which is clearly nonsensical. But batteries don't behave linearly at the extremes of capacity (low or high end) and so things go a little haywire. Enter the API (WattCat's numbers). The software "bends the curves" because the engineers make empirical adjustments in their models at the extremes because the extremes are so unpredictable. Which leads to 5% at 7kWh or Nyland's "oops it dropped from 5 miles to 2 miles in an instant."
And that should be the takeaway from sciencegeek’s post. If you respect your kitty, don’t drive down to zero unless you really have to. Respect your cat. ;)
 
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