Planet-9 Porsche Forum banner

5961 - 5980 of 5993 Posts

·
Registered
Joined
·
39 Posts
The 2013 car is a 2014 model year, UK cars don`t remember.

Even cars that do remember still have smart charging in play which I believe can and will leave the battery under charged if the car is infrequently used or mainly driven on short journeys, this is bad for the battery and shortens it`s life.
Many posters have found when the battery is low stop/start does not work, they are told to either charge or replace the battery, in many of those cases the battery is still within warranty and is actually still good.
Smart charging is supposed to save fuel, no figures are available.

The idea is that the alternator stops charging under engine power when the SOC of the battery reaches a certain level usually around 75 to 80%, this leaves room for quick high voltage charging from overrun and braking.
For a small increase in MPG you are often left with an undercharged battery and have no idea when the battery is in this state.
When you take your foot off the gas the PDK box is put into neutral and the revs drop to around 800 (tick over), at this point the alternator again starts charging the battery at a high voltage which slows the car until you either touch the accelerator pedal or brake, this is called free energy.
If smart charging is deactivated the PDK is still put into neutral on overrun but the alternator which is now on a continuous charging regime only charges at around 14.2 volts instead of up to 16 volts hence the car coasts for a longer distance as there is less resistance from the alternator at 14.2 volts than there is at 16 volts.

With smart charging in play you may gain a small increase in MPG but can regularly end up with a partially charged battery and not know it.
Disconnect the battery sensor and you get rid of both systems this then ensures the battery is always fully charged or near too even on short journeys.

That,s my take on it.
 

·
Registered
Joined
·
5,396 Posts
The 2013 car is a 2014 model year, UK cars don`t remember.

Even cars that do remember still have smart charging in play which I believe can and will leave the battery under charged if the car is infrequently used or mainly driven on short journeys, this is bad for the battery and shortens it`s life.
Many posters have found when the battery is low stop/start does not work, they are told to either charge or replace the battery, in many of those cases the battery is still within warranty and is actually still good.
Smart charging is supposed to save fuel, no figures are available.

The idea is that the alternator stops charging under engine power when the SOC of the battery reaches a certain level usually around 75 to 80%, this leaves room for quick high voltage charging from overrun and braking.
For a small increase in MPG you are often left with an undercharged battery and have no idea when the battery is in this state.
When you take your foot off the gas the PDK box is put into neutral and the revs drop to around 800 (tick over), at this point the alternator again starts charging the battery at a high voltage which slows the car until you either touch the accelerator pedal or brake, this is called free energy.
If smart charging is deactivated the PDK is still put into neutral on overrun but the alternator which is now on a continuous charging regime only charges at around 14.2 volts instead of up to 16 volts hence the car coasts for a longer distance as there is less resistance from the alternator at 14.2 volts than there is at 16 volts.

With smart charging in play you may gain a small increase in MPG but can regularly end up with a partially charged battery and not know it.
Disconnect the battery sensor and you get rid of both systems this then ensures the battery is always fully charged or near too even on short journeys.

That,s my take on it.
Interesting, curious how you determined all of this and its relationship to the battery sensor, is it written up by Porsche somewhere?
 

·
Registered
Joined
·
39 Posts
is it written up by Porsche somewhere?
No,

Firstly it mentions this tech in the 2014 981 Cayman US brochure.
Secondly, when the battery sensor is disconnected the charging voltage on the Porsche freezes at 13.6 volts even though the voltage in my vid below shows the Porsche is actually charging at 14.2 volts, this clearly shows that when the sensor is disconnected smart charging is also deactivated.
When smart charging is in play the voltage can swing from around 13 volts to above 15 volts. I disconnect the sensor the day I bought the car and did not do an actual voltage check with sensor in place as at that time the only interest for me was getting rid of stop/start.
The Merc in vid also had sensor disconnected well over a year ago, I bought the Mec at 3 years old and disconnected the sensor same week, the Merc`s battery is dated 3811 and is still going strong.

Electrical systems
The battery is recharged by the alternator predominantly under braking. Thanks to selective recharging the engine has a bit more power as the alternator doesn't have to generate electricity all the time.
The start/stop function can be deactivated and reactivated using a button on the centre console. The function is deactivated automatically in the event of extreme outside temperatures, low battery charge or activation of the Sport-button.

 

·
PCA Nat'l DE Instructor
Joined
·
1,782 Posts
Thanks for sharing your detailed research on this topic!

Sent from my XT1650 using Tapatalk
 

·
Registered
Joined
·
896 Posts
Took a victory ride to celebrate a record day on Wall St. - def took a beating last week so it felt good to get back some of my losses LOL.

Also, it was pretty epic weather wise - over 60 degrees In winter in NJ.

And I survived Shades of Death Road.

267206


267207


267208
 

·
Registered
Joined
·
5,396 Posts
@Jim137a NJ you say, I was looking at the pictures trying to find snow! Nice that you could get out and turn the wheels over...
 

·
Registered
Joined
·
896 Posts
@Jim137a NJ you say, I was looking at the pictures trying to find snow! Nice that you could get out and turn the wheels over...
‘Hardly any snow this year at all in NJ this winter. I’ve been able to get the Cayman out every month since winter started - I love it.

The temperatures have been so mild this winter it’s crazy, usually the lakes are frozen over but today i actually saw people kayaking and paddle boarding in the middle of winter - crazy.
267209
 

·
Registered
Joined
·
5,396 Posts
Yet up here we have had a very cold January and only now getting back to seasonal temperatures...
 

·
Registered
Joined
·
44 Posts
With temps over 40 today, got the Cayman out to run errands and take 'the long way there and back again'.

Still satisfied (and impressed) with how many bags of groceries and cases of wine I can stuff into this car.

No G-levels to match Jim137, though.
 

·
Registered
Joined
·
896 Posts
Took another spin today to help me forget about my losses in the stock market - yesterday we were up and today right back in the toilet today. LOL.

Hit a few of my favorite spots and slowly getting the G Meter up there.

267229

Hawks Nest- Route 97 just North of Port Jervis NY

267230

Roebling Bridge - Lackawaxen PA

267231


267232

One of NJ loneliest roads ( trust me there ain’t many lonely roads in NJ ) Layton, NJ

267233
 

·
Registered
Joined
·
5,396 Posts
@Jim137a Good plan, go left when the market goes right and zig when it zags! :)

Looks like a great road, one little problem with the bridge, I think the weight of the Cayman will be fine, not sure about the speed though...
 

·
Registered
Joined
·
896 Posts
@Jim137a Good plan, go left when the market goes right and zig when it zags! :)

Looks like a great road, one little problem with the bridge, I think the weight of the Cayman will be fine, not sure about the speed though...
ha ha - its hard to do the speed limit on that bridge - the sound bouncing off those walls is pretty damn good.

The bridge is a pretty amazing piece of history - if I read my history correctly that was John Roebling‘s 1st bridge - his second was the Brooklyn Bridge.

267243

The underside of the bridge.
 

·
PCA Nat'l DE Instructor
Joined
·
1,782 Posts
ha ha - its hard to do the speed limit on that bridge - the sound bouncing off those walls is pretty damn good.

The bridge is a pretty amazing piece of history - if I read my history correctly that was John Roebling‘s 1st bridge - his second was the Brooklyn Bridge.

View attachment 267243
The underside of the bridge.
It was originally built as an aqueduct, with a central, deep channel to float barges of coal to New York City. On either side of the aqueduct were shallower, dry channels for horses to pull the barges across the Delaware River from Pennsylvania. The central channel is now dry, and wide enough to fit one car.

Sent from my XT1650 using Tapatalk
 

·
Registered
Joined
·
896 Posts
It was originally built as an aqueduct, with a central, deep channel to float barges of coal to New York City. On either side of the aqueduct were shallower, dry channels for horses to pull the barges across the Delaware River from Pennsylvania. The central channel is now dry, and wide enough to fit one car.

Sent from my XT1650 using Tapatalk
‘here’s a quick YouTube video on the bridge.


Heres a pic from from the walk way which is above the road surface of the bridge. Vack in the day horse or mule teams would be on the walk way pulling barges across what is now the road surface - obviously what is now the road surface was flooded with water pumped up from the river to float the barges.

267244
 

·
Registered
Joined
·
77 Posts
‘here’s a quick YouTube video on the bridge.


Heres a pic from from the walk way which is above the road surface of the bridge. Vack in the day horse or mule teams would be on the walk way pulling barges across what is now the road surface - obviously what is now the road surface was flooded with water pumped up from the river to float the barges.

View attachment 267244
Thanks for the interesting history lesson :cool:
 

·
Registered
Joined
·
953 Posts
‘here’s a quick YouTube video on the bridge.


Heres a pic from from the walk way which is above the road surface of the bridge. Vack in the day horse or mule teams would be on the walk way pulling barges across what is now the road surface - obviously what is now the road surface was flooded with water pumped up from the river to float the barges.

View attachment 267244
Very cool. I love this stuff. Last September my wife and I took my in-laws down the Mississippi River from Bettendorf to Hannibal, visiting several of the locks and dams and in general the various interesting river towns. Pretty fun and interesting trip.

Thanks for sharing!


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
896 Posts
Very cool. I love this stuff. Last September my wife and I took my in-laws down the Mississippi River from Bettendorf to Hannibal, visiting several of the locks and dams and in general the various interesting river towns. Pretty fun and interesting trip.

Thanks for sharing!


Sent from my iPad using Tapatalk
Would you mind sharing some of the places you visited along the Mississippi?

At the end of May I have to drop off my son at the Air Force Academy in Montgomery AL. The tentative plan is to leave NJ the last week of May and road trip down through VA, WV, TN and then hit PEC Atlanta and then drop him off at Maxwell AFB.

Once I drop him off I plan to head over to Natchez MS and do the 444 mile Natchez Trace Parkway to Nashville but while I’m over by the Mississippi River I’d love to see some cool stuff there - any recommendations on food, lodging and cool stuff to see would be appreciated.

 

·
Registered
Joined
·
953 Posts
Would you mind sharing some of the places you visited along the Mississippi?

At the end of May I have to drop off my son at the Air Force Academy in Montgomery AL. The tentative plan is to leave NJ the last week of May and road trip down through VA, WV, TN and then hit PEC Atlanta and then drop him off at Maxwell AFB.

Once I drop him off I plan to head over to Natchez MS and do the 444 mile Natchez Trace Parkway to Nashville but while I’m over by the Mississippi River I’d love to see some cool stuff there - any recommendations on food, lodging and cool stuff to see would be appreciated.

Well we started in Davenport IA then on to Muscatine IA where we stayed at a fantastic hotel, The Merrill, that I HIGHLY recommend if you are ever up that way. But that’s pretty far north of your current route.


We visited several locks and dams and were able to actually see one in action. Panorama below.




As far as your trip into Tennessee, we used to live near Nashville about 30 miles from the Natchez Trace and it’s a beautiful drive. Be prepared for very slow speeds but it is worth it. Do yourself a favor and stop at Loveless Cafe on hwy 100 at the Natchez Trace. Some of the best food in the Nashville area. The biscuits! And don’t forget pie!

Honestly on the Mississippi trip, we didn’t really have a bad meal, even at some of the more hole in the wall joints.

Interesting little towns with lots of river life museums and of course tourist traps like Hannibal with it being the boyhood home of Samuel Clemens.

We ended at Hannibal and headed back east to Springfield IL to see Lincoln’s burial site then on back to Indy.



Interesting fact about the Mississippi, it begins in Minnesota and you can step across it.

Fascinating river.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
896 Posts
Well we started in Davenport IA then on to Muscatine IA where we stayed at a fantastic hotel, The Merrill, that I HIGHLY recommend if you are ever up that way. But that’s pretty far north of your current route.


We visited several locks and dams and were able to actually see one in action. Panorama below.




As far as your trip into Tennessee, we used to live near Nashville about 30 miles from the Natchez Trace and it’s a beautiful drive. Be prepared for very slow speeds but it is worth it. Do yourself a favor and stop at Loveless Cafe on hwy 100 at the Natchez Trace. Some of the best food in the Nashville area. The biscuits! And don’t forget pie!

Honestly on the Mississippi trip, we didn’t really have a bad meal, even at some of the more hole in the wall joints.

Interesting little towns with lots of river life museums and of course tourist traps like Hannibal with it being the boyhood home of Samuel Clemens.

We ended at Hannibal and headed back east to Springfield IL to see Lincoln’s burial site then on back to Indy.



Interesting fact about the Mississippi, it begins in Minnesota and you can step across it.

Fascinating river.


Sent from my iPad using Tapatalk
Thanks for the info and I def put the Loveless Cafe on my itinerary their menu looks so good.

 
5961 - 5980 of 5993 Posts
Top