Dotted line for limited power available - when do you see it?

[galangg]

I range charged overnight and took the car out this morning.

I did just about manage to make the dotted line appear at very high power and high speeds, but it was much rarer. So it does seem to be related to state of charge. I'll let the car come down to 40% or so and then do the same thing again to confirm.

Still, it's fascinating how half the people on the thread seem to say this is everyday behaviour for their car, and the other half say they've never seen it!

Charging habits maybe?

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aaaand it's back in my head again. I need to unsub from this thread

There could be worse songs to get stuck in your head.

 

[apacheguy]

Still, it's fascinating how half the people on the thread seem to say this is everyday behaviour for their car, and the other half say they've never seen it!

IMO, the reason for that is that people aren't paying full attention to the power gauge as scaescare pointed out:

#2 - When under 40% I can get a "momentary" limiter at the top of the range if I floor it for more than just a bit. You have to be watching for it as it tends to appear within the shaded swept area of the power meter, and it disappears as soon as the needle swings back below the limit.


(I wonder if those who claim never to have seen #2 under those circumstances may have thought you were speaking of a persistent limiter after having floored it once or twice?)

You really do need to be mindful of it because sometimes the limiter is not persistent. That means you only see it when the car is floored and it appears in the orange area thus making it difficult to distinguish.

 

[mgboyes]

You really do need to be mindful of it because sometimes the limiter is not persistent. That means you only see it when the car is floored and it appears in the orange area thus making it difficult to distinguish.

Yes in my experience it's never persistent. I guess I just always glance down and think "oh crap, maybe that's a bit too fast" at which point I see it, and back off, and it vanishes.

"If only there were videos of people accelerating their cars from 0-60 and beyond, and if only they were somehow indexed and stored somewhere on a website I could access" I thought to myself. Oh yes, it's called youtube. Just watched about 10 videos of people taking their P85 from 0 to very quick. In all of them, at around 100mph/160km/h, a yellow limiting line appears at the top of the power meter. Now I'm not doing 100 when I see the line, but it definitely seems to be the same behaviour/effect.

Guess I'll just have to... Let It Go

 

[nikwest]

On the German Highway without speed limit you see the dotted lines a lot. If your battery charge is below 50% it shows quicker. I would not worry about them. For sure it would be nice if they didn't show so often.

 

[David99]

It's most likely to protect the battery. The voltage of any battery needs to be kept within a healthy limit. The lower the state of charge, the lower the voltage drops. The more power you draw from the battery, the lower the voltage drops. To keep it safe and healthy you can't let the voltage drop too low. It would cause permanent damage. When the state of charge is getting down and you push the pedal, the car will protect the battery by limiting the power. I have seen mine go all the way down to 80 kW when I once had to go passed the 0 miles. I'm not sure if the car allows you to push it beyond the limiter. I would definitely be very careful and not exceed it. I think it might also come on when some components get too hot.

 

[scaesare]

It undoubtedly come on for several reasons:

- To protect components that may be overheating
- When the pack charge is insufficient to deliver full power
- When the pack is too cold to deliver full power
- When the park charge is low and the car is attempting to conserve energy

There are likely other situations as well. In all of the ones I've experienced, you can't push the pack (much) beyond the limiter... I say "much" because I actually will see the needle swing past the limiter, but I tend to think this may be more to slight display inaccuracy rather than the car allowing you to do something potentially harmful...

 

[swegman]

What about when the pack is charged fully (100% using range charge)? Thats when I see limit lines, until approximately 3 miles of range is depleted from the full range (258 miles) charge.

 

[mgboyes]

What about when the pack is charged fully (100% using range charge)? Thats when I see limit lines, until approximately 3 miles of range is depleted from the full range (258 miles) charge.

Are you talking about limiting lines on the regen side (i.e. below the zero point on the power meter)? That's simply because when the battery you can't use regen because there's nowhere for the regenerated energy to go.

 

[SarahsDad]

Can't say I've ever seen the dotted line above 20 miles remaining. Below that, yes.

 

[swegman]

mgboyes, no, I'm referring to the limiting lines appearing on the energy usage display (as shown in the picture directly above), but occurring when the rated range is shown as 258 miles. That has happened to me the last two times I did a full range charge on FW 5.12. The lines disappeared after the rated range would drop to about 254 miles. I understand about the limit lines on the regen display when the battery is fully charged, but that is not what I'm referring to.

 

[scaesare]

mgboyes, no, I'm referring to the limiting lines appearing on the energy usage display (as shown in the picture directly above), but occurring when the rated range is shown as 258 miles. That has happened to me the last two times I did a full range charge on FW 5.12. The lines disappeared after the rated range would drop to about 254 miles. I understand about the limit lines on the regen display when the battery is fully charged, but that is not what I'm referring to.

Well that's the first I've ever heard of that. I've never had anything other than regen-limiting at full charge.

Could this have been the battery pack getting too warm as a result of charging for some reason? I'd not expect most home charging circumstances to be able to charge the pack fast enough to cause heat build up....these range charges weren't at superchargers, were they?

 

[swegman]

No, the car was charged at home in the Washington, DC area (its been a mild summer this year) using the UMC (40A at between 239-242V, depending on time of day).