I have been using the cig charger. Very easy and goof proof. No need to pop the frunk.

 

I used to clamp directly to the battery with my S2000, but now I love the Cig lighter plug from Porsche for my tt. It hangs from my garage roof and I plug it in before I get out of the car, 3 seconds...sweet. And I haven't noticed heat problems, but it does sometimes take more than 12 hours to charge fully.

 

i also have the cig. lighter plug for charging battery
great idea, easy as .
p.s. new battery as well
3rd one since 2007 !!!!!

 

This year the car will be in offsite storage with no outlet access. I am curious if it's worth the trouble of removing the battery and charging it at home? Seems like a major pain for $80 wal mart battery