'Hidden' 15% extra range

[Yorkshirepuds]

My dealer recently told me that there is a hidden safety margin of around 15% extra range after running the battery down to an indicated 0%. This would equate to something in excess of 30 miles still available AFTER hitting 0%.

Now I don't intend to test this myself but next week I'm going on a longer trip that will stretch the range if I have difficulty finding a decent (working) charger on the way... so, to relieve a little of the range anxiety, it would be good to know if there is any truth in this.

Anybody else heard (or tried!) this and is it likely to be true?

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[W1NGE]

My dealer recently told me that there is a hidden safety margin of around 15% extra range after running the battery down to an indicated 0%. This would equate to something in excess of 30 miles still available AFTER hitting 0%.

Now I don't intend to test this myself but next week I'm going on a longer trip that will stretch the range if I have difficulty finding a decent (working) charger on the way... so, to relieve a little of the range anxiety, it would be good to know if there is any truth in this.

Anybody else heard (or tried!) this and is it likely to be true?

This is the 'protected' area reserved to manage the overall battery life and I don't think it is a 'reserve' supply of juice. So essentially our 100% charge is actually 85% of available charge capacity and software managed / locked. I think your dealer has misunderstood this point.

 

[XLR82XS]

This is not accurate according to InsideEV range tests. The best you can hope for after zero SOC is to let the car sit for a little time. This may recover a few more miles of range.

That kid from inside EV tested a 4S to 0 range and he had to limp into a charging station. Video on youtube.

 

[kort]

My dealer recently told me that there is a hidden safety margin of around 15% extra range after running the battery down to an indicated 0%. This would equate to something in excess of 30 miles still available AFTER hitting 0%.

Now I don't intend to test this myself but next week I'm going on a longer trip that will stretch the range if I have difficulty finding a decent (working) charger on the way... so, to relieve a little of the range anxiety, it would be good to know if there is any truth in this.

Anybody else heard (or tried!) this and is it likely to be true?

bullocks, your dealer is wrong and giving you bad and dangerous advice

 

[Yorkshirepuds]

This is the 'protected' area reserved to manage the overall battery life and I don't think it is a 'reserve' supply of juice. So essentially our 100% charge is actually 85% of available charge capacity and software managed / locked. I think your dealer has misunderstood this point.

Ah... pity! I thought it sounded too good to be true.

Thanks all for clearing that up.... I'll not be testing it myself now!

 

[MJDCT]

Who cares, you've got a yorkie wheel.. just imagine

 

[Yorkshirepuds]

Who cares, you've got a yorkie wheel.. just imagine

They're the 21" Yorkshire Pudding Design aero wheels (the aero wheels need just 10 mins in the oven longer than the non aero) ?

 

[MJDCT]

They're the 21" Yorkshire Pudding Design aero wheels (the aero wheels need just 10 mins in the oven longer than the non aero) ?

bring on the gravy puddles.

 

[bruksnys]

It's TRUE! I just came from Porche center, ordering my new Taycan CT, they said that they just came from a racing event, where they were doing some racing laps. Two Taycans came a little bit short with range so they just kept going, one came to finish with decent speed with 0 battery left and 20 kilometers (did not need to go further, it did not died) and another one came with MINUS 5% battery on their onboard computer. Not 0, but it actually showed a number MINUS 5% and were still going

 

[Deleted member 1697]

people : 0%soc is dangerous for the battery lifetime
porsche : 15% hidden extra range
people : 100%soc is dangerous for the battery lifetime
Porsche : 15% hidden extra range also

 

[plumandreal]

bullocks, your dealer is wrong and giving you bad and dangerous advice

Agreed!

When you hit zero it has no spare range. And it cuts out. And it doesn't charge at Normal speed from this point.

And yes I've done it. And won't do it again!

 

[daveo4EV]

It's TRUE! I just came from Porche center, ordering my new Taycan CT, they said that they just came from a racing event, where they were doing some racing laps. Two Taycans came a little bit short with range so they just kept going, one came to finish with decent speed with 0 battery left and 20 kilometers (did not need to go further, it did not died) and another one came with MINUS 5% battery on their onboard computer. Not 0, but it actually showed a number MINUS 5% and were still going

My dealer recently told me that there is a hidden safety margin of around 15% extra range after running the battery down to an indicated 0%. This would equate to something in excess of 30 miles still available AFTER hitting 0%.

Now I don't intend to test this myself but next week I'm going on a longer trip that will stretch the range if I have difficulty finding a decent (working) charger on the way... so, to relieve a little of the range anxiety, it would be good to know if there is any truth in this.

Anybody else heard (or tried!) this and is it likely to be true?

• there is a buffer
• it’s not used in this manner
• your dealer is confused - normally I’d point & laugh - but this stuff is new to everyone so I‘ll give them a “pass” this one time
• this LiON battery stuff is truly confusing - so this is actually a good question
• you can drive a bit “past” 0% but actual amount will vary based on a lot of circumstances - really no different that gas gauge being empty
• basically what you as a consumer are allowed “see” is a sanatized/simplified view of the battery state
  • 0% is NOT the “true” physical 0% at the physical battery cell level - it simply means you reached the “end” of the amount of power Porsche has decided to let you use for this charge cycle
    • if you were allowed to reach absolute LiON cell 0% - the battery would be bricked - and you’d need a new battery
  • 100% is NOT the ”true” physical 100% - it’s the amount of power Porsche has decided to let you use this time
    • storing LiON batteries at 100% SOC for long periods are stressful to the battery and reduce battery longevity
• how much power 0% and 100% actually represent will vary with: time, age, weather, driving conditions, temperature, number of total charge cycles, battery health, your last few charging session, and a impressive list of random factors…LiON batteries and their capacities is not a precise affair - it’s bit of fuzzy math - that works well in the “middle” but at the actual “edges” (0% and 100%) you lose precision and can not actually precisely measure/predict where that will be…
  • solution: stay in the middle - and do not get near the edges when you can’t really know
  • Techinque: don’t push boundaries here - give yourself as healthy buffer so that you never place the battery “near the edges”
  • Result: Battery Management Software that manages the battery’s true capacity and keeps the battery in the “safe” zone away from the edges where the Fuzzy math can’t predict behavior
    • this means holding back a certain amount of battery capacity that while it’s there is unusable because to use it would damage the battery cells…

People keep asking:

Oh great internet what can I do to manage my battery for reason {blah}…

my response

Nothing! There is soooo much software between you and the actual physical battery - there is virtually nothing you as the consumer can do to influence the batteries behavior, age curve, or capacities, or wear/tear…

Porsche has a sophisticated and well developed Battery Management system and it has sole authority for all things “battery” - it contros horizontal and the vertical - and all things are filtered through the BMS - it’s job is to keep the battery in it’s safe “zones” - volatage, amps, temperature, capacity, charging speed, discharge speed, etc…it’s main purpose is to prevent warranty cliams - i.e. keep the battery in the “safe/warranty” zone for 100,000 mlies or 8 years…

so there is nothing you can do to influence the battery - because you have software on board the vehicle that knows the “true” state of the battery - and it’s _JOB_ is to keep you the consumer from doing anything at any time that would push the battery into conditions that will cause a warranty issue…

Porsche has complete control here via the BMS - and what the battery can and can not do is behind a locked door in a locked control room cause the “BMS” which is a software black box in every modern EV that is keeping these LiON batteries working for us - it’s a bit like fly by wire fighter jets - without the software you couldn’t actually keep the jet in the air using just human skills and sensors…

BMS is the current great variable between EV manufactures and one of the few places where the EV experience can vary between different vendors…

 

[NormF]

A ran a “know my car” experiment, driving it down to 1% SOC (near my home, in Range mode). What I found was that in the last 50 Km the battery has more range than it shows - at least 10% more. In other words, the Porsche software has a built in conservatism factor. And it seemed very predictable, with no sudden changes in the indicated range. You can count on the fact that you will be able to travel at least as far as the range is showing as it gets to a very low SOC. I also listened to an EV expert who said that it is useful to periodically take most EV’s down to a low SOC so that software can re-calibrate low SOC. Don’t leave it there, immediately re-charge.

 

[Brazz]

Hello. I’m new to the forum and have been reading a lot of posts about batteries and charging. I just ordered a 4S with delivery expected March. The battery posts are confusing. The manual states to charge to 80% versus 100% for daily use, but there is a 15% buffer as posted. So, effectively if we charge to 100%, we are theoretically only at 85% with the buffer. And, if we charge to 80%, as recommended, we are effectively at 65% of battery capacity considering the safety buffer. So, we should be safe to charge to 100% (effectively 85%) and the range of the battery is maximum to our ability and still protected by Porsche’s buffer. Am I missing something??? Confused….

 

[REIL]

Hello. I’m new to the forum and have been reading a lot of posts about batteries and charging. I just ordered a 4S with delivery expected March. The battery posts are confusing. The manual states to charge to 80% versus 100% for daily use, but there is a 15% buffer as posted. So, effectively if we charge to 100%, we are theoretically only at 85% with the buffer. And, if we charge to 80%, as recommended, we are effectively at 65% of battery capacity considering the safety buffer. So, we should be safe to charge to 100% (effectively 85%) and the range of the battery is maximum to our ability and still protected by Porsche’s buffer. Am I missing something??? Confused….

You may find this thread of interest if you have not seen it yet.
https://www.taycanforum.com/forum/threads/how-many-charge-to-100.4635/page-8#post-104456

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