2019 Cayenne Battery
01-18-2022, 12:49 PM
#93
_IF_ the Cayenne eHybrid’s “big” battery were to be able to charge the “little” battery - there at a minimum would need to be a DC/DC converter to step down the higher voltage big battery to the vehicle’s 12 volt normal capacity - this seems un-necessary to me given that the Cayenne eHybrid has an alternator - and this add complexity in: design, manufacturing, maintenance, and software. also the “big” battery maintaining the little battery is not a panacea - as the Taycan right now is experiencing “dead 12V” battery issues where the 12V drops offline during charging (a time when there is plenty of power to go around) - so it also is no guarantee the 12V battery will be well maintained…
my speculation is the two systems isolated for simplicity and safety.
my speculation is the two systems isolated for simplicity and safety.
https://www.excellence-mag.com/issue...ybrids-systems
Based on this article it does seem like there is a DC/DC converter.
Granted this is from 2015, I would assume they didn't make drastic changes.
I seem to be having some trouble with my12V battery, the alarm will go off randomly and overnight my comfort access stops working, which leads me to believe it is the 12V battery. I have to switch the ignition on/off to activate the comfort access again.
The presence of the E-machine negates the need for a conventional 12-volt starter motor or alternator. The possibility of electric-only operation requires an air conditioning compressor that is driven via high-voltage AC power instead of the usual belt drive from the combustion engine. The E-Hybrid battery control unit can also activate the air conditioning compressor independently of the driver to provide extra cooling to the Li-ion battery pack as necessary.
One of the main challenges of hybrid automation is converting the different forms of electricity generated by the system to suit the various on-board electrical devices. The battery pack supplies high-voltage direct current (DC), yet the E-machine is an AC motor. Most of the on-board accessories are powered by conventional 12-volt DC power, so a 12-volt battery is maintained as such. All Porsche hybrids employ a “power electronics” unit that performs all the necessary electrical conversions to ensure smooth powertrain operation.
The power electronics unit contains a pulse-controlled inverter to convert the high-voltage DC current supplied by the battery pack into usable AC current to drive the E-machine. Conversely, the same inverter rectifies the AC voltage that is recuperated during braking and uses it to recharge the high-voltage battery pack. A DC-to-DC converter is also present to safely convert the high voltage from the main battery pack to the lower voltage necessary to charge the 12-volt accessory battery. The rapid switching of the power electronics unit generates a lot of heat, so it is liquid cooled.
Ironically, if the on-board 12-volt battery of a Porsche hybrid becomes fully discharged, the vehicle will be inoperable because all the electronic control units that orchestrate the powertrain management use the 12-volt system. If this occurs, the 12-volt battery can be charged conventionally with a normal battery charger. The E-Hybrid has an additional on-board charging module to enable charging of the Li-ion battery pack via 120-volt home AC power, or with a special Porsche-designed 240-volt charging setup.
One of the main challenges of hybrid automation is converting the different forms of electricity generated by the system to suit the various on-board electrical devices. The battery pack supplies high-voltage direct current (DC), yet the E-machine is an AC motor. Most of the on-board accessories are powered by conventional 12-volt DC power, so a 12-volt battery is maintained as such. All Porsche hybrids employ a “power electronics” unit that performs all the necessary electrical conversions to ensure smooth powertrain operation.
The power electronics unit contains a pulse-controlled inverter to convert the high-voltage DC current supplied by the battery pack into usable AC current to drive the E-machine. Conversely, the same inverter rectifies the AC voltage that is recuperated during braking and uses it to recharge the high-voltage battery pack. A DC-to-DC converter is also present to safely convert the high voltage from the main battery pack to the lower voltage necessary to charge the 12-volt accessory battery. The rapid switching of the power electronics unit generates a lot of heat, so it is liquid cooled.
Ironically, if the on-board 12-volt battery of a Porsche hybrid becomes fully discharged, the vehicle will be inoperable because all the electronic control units that orchestrate the powertrain management use the 12-volt system. If this occurs, the 12-volt battery can be charged conventionally with a normal battery charger. The E-Hybrid has an additional on-board charging module to enable charging of the Li-ion battery pack via 120-volt home AC power, or with a special Porsche-designed 240-volt charging setup.
06-28-2022, 11:29 AM
#94
Rennlist Member
Pickup new GTS last Saturday with the lithium battery. Received PCM message of low voltage connect charger while running PCM with key on. Obviously spent too much time without engine running. Picked up the Porsche charger and on the 2nd try (using 12v port) it went to bulk mode. Monitored for an hour but had to leave. Using the garage security camera it appeared to stay in bulk mode after 12 hours, though it could have changed to absorption mode but on the camera it was hard to tell exactly which light was on. This morning the power light was flashing indicating an error. I assume it’s due to UVP but will verify when I get back to the car today. It may have been caused but the port becoming unavailable but seems unlikely. Does this seem odd that it would charge this long before sensing UVP?
06-28-2022, 03:18 PM
#95
Rennlist Member
The car was not in UVP mode. Light all came on and started fine. Picked up alligator clips and installed the charger direct to the posts under hood. Charger cycled through accept and bulk quickly stopping in absorption. All appears normal. I suspect the 12v went to sleep maybe when charger switched to lower voltage. Only direct connecting in the future.
06-28-2022, 07:24 PM
#97
I can't understand why Porsche won't recall the Lithium batteries and change to AGM ones. The new 2022 Cayennes are coming out with AGM batteries, so they realise it's a load of bullplop!
I've just sent mine off to be repaired.. £300
I've just sent mine off to be repaired.. £300
06-28-2022, 08:51 PM
#98
Rennlist Member
My GTS was built in May and just delivered last Saturday. Lithium batteries are still being installed. Not sure what triggers a lithium but I do have PDCC and RWS.
06-28-2022, 10:35 PM
#99
Rennlist Member
FYI
I have an AGM with RWS and PDCC. Feb build, May delivery.
I was told by the dealer that AGMs were used when Lithiums were not available and has nothing to do with Porsche’s dissatisfaction with using Lithium or options on the build.
I have an AGM with RWS and PDCC. Feb build, May delivery.
I was told by the dealer that AGMs were used when Lithiums were not available and has nothing to do with Porsche’s dissatisfaction with using Lithium or options on the build.
06-28-2022, 10:43 PM
#100
Rennlist Member
06-28-2022, 10:51 PM
#101
Common sense suggests there is a compelling technical reason why Porsche would use a lithium battery that’s difficult to source and costs over $1k to replace, rather than a widely available and enormously less expensive AGM. Which leads me to wonder whether our 2022s, with AGM batteries rather than lithiums, will be more susceptible to starting problems in severe conditions or degraded performance over time.
06-28-2022, 11:14 PM
#102
Rennlist Member
https://presskit.porsche.de/workshop...e-cayenne.html
From the 9YO Press Kit:
Thanks to its sports car genes, the completely new lightweight construction of the chassis delivers excellent driving dynamics that surpass expectations for this segment. In designing the new Cayenne body, Porsche has consistently applied the same lightweight construction principles that it uses in its sports cars.
Compared to the equivalent model from the first generation back in 2002, the weight saving equates to 225 kilograms, or around ten per cent. The innovative lithium-ion-polymer starter battery – which weighs ten kilograms less than comparable traditional lead batteries – makes a further contribution to the weight savings. It also offers a three to four-times longer service life.
Compared to the equivalent model from the first generation back in 2002, the weight saving equates to 225 kilograms, or around ten per cent. The innovative lithium-ion-polymer starter battery – which weighs ten kilograms less than comparable traditional lead batteries – makes a further contribution to the weight savings. It also offers a three to four-times longer service life.
Last edited by Schnave; 06-28-2022 at 11:42 PM.
06-28-2022, 11:46 PM
#103
Rennlist Member
I had an electrical error on the instrument cluster after only 600 miles, however my working theory is the battery wasn’t fully charged. It sat for awhile at port and at the dealer. I was hovering over it when the amp came in and took delivery shortly after they installed the amp. I did a series of short drives initially followed by 1 week of “normal drives”.
I’ve had it on a CTEK for 6 days since getting it back from the dealer after I brought it in for the electrical error message (dealer cleared all codes). I’ll see if I experience any issues this week.
Hope the performance of the AGM is equivalent to the lithium. I doubt I’d notice the weight difference on a SUV.
I’ve had it on a CTEK for 6 days since getting it back from the dealer after I brought it in for the electrical error message (dealer cleared all codes). I’ll see if I experience any issues this week.
Hope the performance of the AGM is equivalent to the lithium. I doubt I’d notice the weight difference on a SUV.
Last edited by abokor; 06-28-2022 at 11:48 PM.
06-30-2022, 08:16 PM
#104
Rennlist Member
https://www.excellence-mag.com/issues/292
Also check out the link for a great article on the Cayenne GTS!
Porsche was the first car maker in the world to offer a Lithium starter battery. The lightweight, 13 pound, 18 Ah battery was available for the 2010 GT3 and Boxter Spyder as a €1,904 option.
https://www.porsche.com/middle-east/...ternational-de
The second generation battery was conventionally shaped and boasted a 40 Ah capacity. It was offered beginning in 2013 on the 991.1 GT3 and Cayman GT4. This battery was not powerful enough for the Cayenne.
(Source: Excellence, Issue 292)
In 2016, Porsche was in the process of redesigning the Cayenne 958.2 with an emphasis on weight reduction, as I posted earlier. In November 2016, the EU proposed a complete ban on the use of lead which would have decimated the automotive battery industry.
https://www.xing.com/communities/pos...ies-1012416615
Given this proposed ban and the weight reduction goals of the redesign, Porsche decided to task two battery suppliers (A123 Systems and LG Chem) to develop a lightweight 60 Ah lithium battery to power the new Cayenne 9YO. To help amortize costs, the battery was also offered in the Bentayga and Urus. It was later installed in the 2020 992 and as the accessory battery in the Taycan.
(Source: Excellence, Issue 292)
So there you have it. The reasons were both technical and political!
The proposal to ban lead in batteries is still alive and if implemented, will send shockwaves through the automotive industry. As if we need another shock to the industry right now.
https://www.assent.com/blog/lead-fur...d-under-reach/
https://www.bestmag.co.uk/eu-proposa...ough-industry/
Bonus Picture: The 9YO battery with the top removed. Check out the circuitry for the Battery Management System.
Last edited by Schnave; 06-30-2022 at 09:55 PM.
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LSR (06-30-2022)
08-01-2022, 08:24 PM
#105
Replacement LifePO4 Lithium Battery Replacement
Fyi, I've been having low voltage issues on my 2019 Cayenne S The first warning sign was Porsche Connect calling to inform me that my car was reported stolen. This happened about 6 times. I am guessing, but it seems that when the voltage is low, it triggers theft alerts.
I failed to recognize these signs. I did note the onscreen battery voltage read normally. No other warnings were shown.
I went on a 6-day trip and parked the car in the garage. When I returned the car was totally dead. I called my dealer and they told me to call Porsche road service, get a jump and then drive the car for an hour.
I had Porsche send a wrecker.. They sent a pickup truck to jump-start. The jump start worked, and I drove on the highway for an hour. As soon as I came home and switched off, the car was dead again.
I went to the Porsche dealer to inquire. They thought it might be a battery issue. The replacement of this battery is $2100!!!
FYI, this model year has no key access to the trunk. No battery power = no open trunk. Since you need the wrench in the trunk to disengage the transmission for towing, this is a problem. I would consider relocating this red wrench from the trunk to a more accessible location.
Please give let me know your thoughts! Thanks! Hope this helps someone.
I failed to recognize these signs. I did note the onscreen battery voltage read normally. No other warnings were shown.
I went on a 6-day trip and parked the car in the garage. When I returned the car was totally dead. I called my dealer and they told me to call Porsche road service, get a jump and then drive the car for an hour.
I had Porsche send a wrecker.. They sent a pickup truck to jump-start. The jump start worked, and I drove on the highway for an hour. As soon as I came home and switched off, the car was dead again.
I went to the Porsche dealer to inquire. They thought it might be a battery issue. The replacement of this battery is $2100!!!
FYI, this model year has no key access to the trunk. No battery power = no open trunk. Since you need the wrench in the trunk to disengage the transmission for towing, this is a problem. I would consider relocating this red wrench from the trunk to a more accessible location.
Please give let me know your thoughts! Thanks! Hope this helps someone.
Last edited by dbwalsh; 08-01-2022 at 08:26 PM. Reason: punctuation