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Discussion Starter #1
As I was driving on the highway this morning I noticed the battery gauge dropping rapidly. I was actually about to get off on my exit and let off the accelerator- and as I'm slowing down and going into the turn-off it just keeps dropping. The car is regenerative braking at this point- no accelerator, no heat on- and it lost about 6% in 15 seconds. Now usually the battery does not go down when you are actively regenerative braking so this is really weird.

I've noticed this rapid battery gauge loss at other times, when the car is getting low on charge, and at other times when it's cold out. The gauge is not reliable at any low charge in my opinion and I've noticed it dropping down percentages even at stop lights. I figured it was my imagination since people talk about "range anxiety" - but this is actually happening with this battery gauge not being as reliable as I think it should be. This morning is colder than usual, in the 40's and I was taking a 40-mile round trip at highway speeds it I started off at about 90% battery. Usually that would take the battery down to 35-40%. Today I'm getting home with 12% battery as the gauge was dropping so fast in the last 10 minutes of my commute. My only guess is that it could have been wind chill even though if that's the reason then it's rather unexpected at almost 45 degrees. Or perhaps the top-end of the battery is mis-calibrated and reporting more charge than it actually has.

I'm just wondering if anyone else has experienced the gauge dropping for no reason or much more rapidly than it should be?

Assuming there's a theoretical "fix"- I'm a firm believer that we should not be engaging in self-fixes for this car. The 500e should be programmed in such a way to not report false information, including current charge level, and should not require constant user-interaction, fixes, or 3rd party tools. It should be doing what it's designed to do.
 

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As I was driving on the highway this morning I noticed the battery gauge dropping rapidly. I was actually about to get off on my exit and let off the accelerator- and as I'm slowing down and going into the turn-off it just keeps dropping. The car is regenerative braking at this point- no accelerator, no heat on- and it lost about 6% in 15 seconds. Now usually the battery does not go down when you are actively regenerative braking so this is really weird.

I've noticed this rapid battery gauge loss at other times, when the car is getting low on charge, and at other times when it's cold out. The gauge is not reliable at any low charge in my opinion and I've noticed it dropping down percentages even at stop lights. I figured it was my imagination since people talk about "range anxiety" - but this is actually happening with this battery gauge not being as reliable as I think it should be. This morning is colder than usual, in the 40's and I was taking a 40-mile round trip at highway speeds it I started off at about 90% battery. Usually that would take the battery down to 35-40%. Today I'm getting home with 12% battery as the gauge was dropping so fast in the last 10 minutes of my commute. My only guess is that it could have been wind chill even though if that's the reason then it's rather unexpected at almost 45 degrees. Or perhaps the top-end of the battery is mis-calibrated and reporting more charge than it actually has.

I'm just wondering if anyone else has experienced the gauge dropping for no reason or much more rapidly than it should be?

Assuming there's a theoretical "fix"- I'm a firm believer that we should not be engaging in self-fixes for this car. The 500e should be programmed in such a way to not report false information, including current charge level, and should not require constant user-interaction, fixes, or 3rd party tools. It should be doing what it's designed to do.
We're sorry to hear that you are experiencing this concern. If you would like any additional assistance, our team is always available via private message!

Alison
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My guess is that the battery state of charge algorithm is adjusting itself for temperature. I've seen that a few times at least.

Sometimes driving against strong wind does a lot significantly increases the power. Also the cabin heater is around 7 kW alone, which often is the main reason of sudden drop.
 

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I'm a firm believer that we should not be engaging in self-fixes for this car.

Sorry, no offense, but if you don't want a theoretical self-fix, don't discharge PAST zero, & don't unplug the humidity sensor :) . Just take it to a dealer where they will almost certainly say nothing's wrong.

Discharging only TO zero has been reported unsuccessful, so you'd want to park by the charger with all the lights on, rear defog, & maybe fan on hi (heater & A/C won't work) for a while, preferably until OBD shows 0.00%, or you get a 12V battery warning: Regain Lost Range for Free!
 

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Mine has done similar, although not as drastic as yours. I have lost 4% at times In a matter of seconds. The times it happened has been when I was below 30%. I asked about it on this forum and the explanation was the system is recalibrating itself. This seems to be the case for mine. All is fine the next day and goes weeks before doing again. Another factor was temperature. Mine also did it at colder temps. I would think yours did a re-calibration on the fly and hopefully all will be back to normal tomorrow. Makes for same anxious moments though....😏
 

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Discussion Starter #6
Thanks for the replies. Recalibration sounds plausible... I guess I'm just disappointed. I drove about 35 miles before that happened. I have barely driven the car in the past few weeks. I left it at around 60% for a few days. Then charged it up to 90% the day prior. It was just a slightly colder day than usual, about 45 degrees and I've driven the car in much colder weather than that. But I have never seen the gauge drop that rapidly in the span of just a few seconds.

I have several small video cameras- I might start pointing one at the dashboard to record it in case it happens again.
 

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Thanks for the replies. Recalibration sounds plausible... I guess I'm just disappointed. I drove about 35 miles before that happened. I have barely driven the car in the past few weeks. I left it at around 60% for a few days. Then charged it up to 90% the day prior. It was just a slightly colder day than usual, about 45 degrees and I've driven the car in much colder weather than that. But I have never seen the gauge drop that rapidly in the span of just a few seconds.

I have several small video cameras- I might start pointing one at the dashboard to record it in case it happens again.
I'm sorry to hear this. Please feel free to reach out via private message!

Alison
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This is a common occurrence with these cars. My 2016 did it, and now my 2017 does it. The battery charge percentage will sometimes drop rapidly from ~24% to ~16% in a matter of seconds from one percentage point down to the next. It seems to be more prevalent in cooler weather. It does not appear to affect the remaining distance calculation so much. It appears to be normal and nothing to be worried about.
 

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Thanks, that's kind of nice to know, IF by "distance calculation" you mean what we personally estimated prior to the drive.

However if you mean the GOM most of us ignore for good reason, then it doesn't help as much.
 

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So it’s kinda like my VW where first half the rank the gauge barely moves but 1/2 on done it seems to dive every 20 miles.
 

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Except that your VW probably does that consistently, much like an eGolf by the way.

The problem with the 500e is that it normally does NOT do that, & then all of a sudden one day you're 28 miles from home with a reasonably-comfortable 30%, & it suddenly drops to an "I won't make it" 22%.

Maybe less stressful if we try to always remember Abe's advice above, so when it does happen, just try to ignore it, because it's just the gauge that's messed up. Then try to recalibrate the gauge with "past zero, then charge non-stop to full". Then it might not do it again for a few years.
 

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I just had a pretty long freeway trip driving my 500e from home in Monrovia area to compton, to Tustin and back to compton and had it doing this. 100% of trip was with AC on as it was a warm day I was at 24% then I was literally watching it drop to 23-22-21-20-19-18-17-16% in 30 second span as I was coming to a stop off the freeway then ending up at 14% I was like oh wtf.
108614
 

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Discussion Starter #13
I just had a pretty long freeway trip driving my 500e from home in Monrovia area to compton, to Tustin and back to compton and had it doing this. 100% of trip was with AC on as it was a warm day I was at 24% then I was literally watching it drop to 23-22-21-20-19-18-17-16% in 30 second span as I was coming to a stop off the freeway then ending up at 14% I was like oh wtf.
Yeah, it's exactly the same thing I experienced. I was going highway speeds for an extended period of time then slowed down (regen braking).

My only observations on my trip are that:
  • I did not charge to 100% so battery cells may have been at un-even charge
  • I took a longer trip than usual at highway speeds.
But even if that's true then it's just normal driving, so not sure I can even fault myself.
 

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Mine was 100% charged up as I knew I was gonna need every last bit of it. What I most found peculiar is discharging like that while Regen braking and stopped at a light off the freeway. Here is me pre air conditioning While plugged in before leaving notice the huge difference in temperature though 108 degrees yikes
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What I most found peculiar is discharging like that while Regen braking and stopped at a light
Thanks for the reports.

It's not actually "discharging" *. It's the gauge.

& if a driver doesn't happen to be watching the gauge during the 30 seconds when it drops, they might understandably think (& even report) that it's range loss from battery degradation, even though it's not.

It seems to have happened to me recently too, but I just didn't happen to be looking at the gauge: I needed to drive about 65 miles roundtrip, partly on light-traffic freeway, so I charged to full. Based on nearly 5 years experience with this as my only car, I expected to get back with at least 20% (80% used).

I got home with only "11%" on the gauge (89% used) but it does NOT seem to be from range loss. OBD showed 95% at "full" charge, & 18% when I got home (77% used). Since then I've driven several of my standard 32 mile commutes using 32%, same as always.

So here's a question: It seems like we can recalibrate our % gauges with discharge past zero & non-stop full charge, but if OBD can get a better reading of % charge, why doesn't the display gauge just show that?


* Someone please check my math: 7% discharge in 30 seconds would be about 529 amps, which would almost certainly have destroyed the battery, with lots of smoke & probably fire.
 

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Don’t forget that was while regening which makes it even more wierd as I was seeing 22-45kw going back to the battery while doing so.
 

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Right. My point is it's "just" the gauge, not actually the battery discharging or losing range.

I'm still wondering why the gauge doesn't show the seemingly-more-accurate OBD %.
 

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Because FCA, things are more complicated then it has to be...
 

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Right. My point is it's "just" the gauge, not actually the battery discharging or losing range.

I'm still wondering why the gauge doesn't show the seemingly-more-accurate OBD %.
Maybe, for the same reason as "the other right" with the burnt out bulb ;-) Give FCA coders some espressos, g'******.
 

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Do you think the vast difference in ambient temperatures have anything to do with the soc? I went from leaving in 108 degree heat to 80ish compton to 74 degree Orange County. I would imagine the bms would handle that with all the cooling tech onboard this ain’t a leaf.
 
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