C-Tek charger issues with cigarette lighter connection!

[macfly]

If you decide to upgrade to a C-Tek charger, as I did because several of our owners were so exceptionally vocal about being so much better than the standard BMW/Deltrans unit, be warned, I have discovered a bug using it that can destroy your battery.

Initially I suspected I'd made a mistake when I went to start my car, and found that despite being on charge, I had a totally dead battery. I figured that maybe I'd somehow left the ignition on, but now I've caught it doing what it does three times, and realize what is happening.

If like me you leave the key in the ignition, so it also gets a charge, there is something odd with the pairing of the C-Tek and the BMW electrical system. After about four or five minutes it will actually turn on the cars electrical system if the key is in the ignition when you connect it to the cigarette lighter socket! As I leave all my doors, trunk and hood popped to preserve the seals, the complete alarm system, the little lights, the warning dings all come on, and remain on. By that time my car is covered, and I'm back in the house with the garage door closed and the music on, so I'd never heard its gentle dinging under the covers.

However since I've been getting a consistently low power readings on my brand new battery, I've been monitoring it more closely, and just this evening caught it out again.

It seems that if you want to charge the battery with the key in the ignition, you must first remove the key, then connect the charger and once it is on, and showing you its level of charge, replace the key. So far doing it this way has not brought on the problem, but if I do it the other way, sure enough the electrics wake up on their own.

I'd honestly say the BMW/Deltrans unit is better, as I never had an issue with it, but when I ran mine over by mistake I decided to 'upgrade'. I wouldn't recommend the C-Tek based on my experience.

[Kevin]

But is it okay as long as the C-Tek is plugged in but the key isn't in the ignition?

[macfly]

Yes, I think so, I think there's something about the key being in the ignition slot that allows the base system to be activated.

[Z8Mania]

Ive never had a single problem with the ctek but I go straight to the battery. Going straight to the battery is the recommended practice.

I have a friend who had the deltran unit start a fire so I moved way from those units years ago.

I've also never left my key in the car and its always worked so go figure!

[Z8LVR]

I didn't see this post earlier, but over the past winter my Alpina did exactly as Andrew described, died, yet my Z8 did not. The Z8 worked fine running the C-Tek through the lighter, but not the Alpina. I did not remove and insert the key again - the last thing I did was connect the charger. I do keep the key in for charging as recommended by BMW. I also leave my seals open (doors, windows, top, hood, trunk ) during storage on both cars, but did see all the lights go out after a short period. Really had me wondering why only a dead battery on the Alpina... Now, WHY??

[Z8Mania]

I can't explain it but I think its best to go direct to the battery.