Is a batt tender necessary?

[MikenOH]

I've had 2--for our 06 and 99 Boxsters; I highly recommend them. Our 99 had the OE battery when we sold it and I think part of the longevity is due to the tender we kept it on. I got it from wally world for $25.

The 06 has the porsche tender with the cigarette light adapter; it works equally well but is more expensive--about $60.

BTW, you'd be suprised how much starting the car in cold weather and short drives can drain the battery; I did that a few times last month and the trickle charger was charging for nearly a day.