I've been using this charger on and off throughout the winter. Basically, I'd plug the unit into 12V socket in the car and then plug it into the wall outlet and leave it overnight. In the morning, when the light on CTEK turns green, I'd unplug it and not use it for a week or two. The question I have is this: am I doing it right? Would it be better to just leave it plugged in? Is there any danger in leaving it plugged in (and unattended) for a long period of time? Thank you.

 

Your way is fine. So is leaving it plugged in as long as the cord is out of harm's way.

 

I unplug mine after I have used it, but I don't think it would matter either way.

 

No danger in leaving it connected all the time. It is designed for that. You wouldn't want to forget it was unplugged and find your battery drained - that would be annoying. Mine is plugged in for months over winter.

 

When I get out of the car I plug mine in. Have CTEK on three cars. It is a great product. I like it much better than the old battery tenders I had.

 

In the case of the Ctek 3A unit, its point is to charge the battery and maintain it. If you charge it overnight and disconnect it, the battery will discharge. 997 batteries discharge about 25% of their capacity per week with the car sitting idle... If I use this unit I leave it connected until I drive the car.

 

You are better off leaving it attatched. An enemy of batteries is sulphonation. There are lots of threads on avoiding and dealing with sulphonation on boat battery threads, but the bottom line is that keeping it charged up helps decrease this.

 

I leave mine plugged in. I do too many short trips which can kill a battery - my last car had to have a new one after only 3 years. My sister who has a short commute had the same problem. With previous cars I had when I used to travel a lot, the batteries lasted beyond my ownership.

 

mine is on all winter.........always have.......