Hi, I‘ve had a C-Tek 5.0 for several years and in my opinion it is excellent. It does charge the battery of my wife’s car which has stop/start technology. She does numerous short journeys with everything switched on, giving the battery little change to recharge.
If it’s primarily to maintain the battery on your Boxster I would go for the stop/start version but if like me you will use it on older cars I might get the 5.0. A major advantage of the C-Tek 5.0 is that it is capable of recovering a totally flat battery but if you only need a trickle charger to keep your perfectly good battery topped up, the cheap but reliable Aldi or Lidl chargers do a good job. I use one of those too.
If it’s primarily to maintain the battery on your Boxster I would go for the stop/start version but if like me you will use it on older cars I might get the 5.0. A major advantage of the C-Tek 5.0 is that it is capable of recovering a totally flat battery but if you only need a trickle charger to keep your perfectly good battery topped up, the cheap but reliable Aldi or Lidl chargers do a good job. I use one of those too.