My 2018 Cayenne was spending lond spells not used and noticed as expected battery was loosing charge.
So i bought the porsche trickle charger i began by charging via engine bay connections to battery using croc clips but found the bonnet strut when closing the bonnet was fouling the earth terminal. This made it fiddly as i had to clip croc clip facing down below the engine bay cover nevertheless it did the job and fully reconditioned the battery .
I discussed this with technical support (Maz) who was very helpfull he explained croc clips not ideal for my applicationand spring tension would probably decline with use and gave me a couple of alternative options.
Adapt the teminal washer type terminals and or charge using in car socket.
Ive done both removed earth terminal and tapped end M8 to match thread on positive terminal and converted the washer terminal to open end so i can slide under the new M8 bolts works fine no fouling of strut.
I did this initially because i was told the Cayenne software isolates the 12v sockets when ignition is turned off unless a power source is dereected within 1-1.5mins!!
This was the next thing i tried connected up cigar lighter from charger power off .
Turned on car ignition then back off .
Switched on charger hey presto charger up and running in car so in reallity i should of tried this first but never ming i have two options now thanks for all of your support great to be able to talk to someone these days especially having knowledge of the product they are selling.
Keeps battery topped up when car has little use in winter - just plug into cigarette lighter socket - so no messing removing panels under bonnet - so when you want to drive car it takes less than a minute to unplug and away you go
Arrived quickly even over the holiday period, works as described and holds levels.