Griffin Power Jolt Car Charger for 3G??

Anyone have the black Griffin Power Jolt Car Charger for the iPhone 3G?

Anyone have any bad luck with this charger?

I had my phone plugged in and the phone filled up according to the charger, and then it kind of went back down a bit and the charger light went from red, to green (indicating full) and then back to red.

I feel like ever since then, my iPhone 3G batter has not held a charge as long.

Am I just being paranoid?

No, it wasn't really warm.

I just found it odd that the light on the charger turned Green to indicate a full charge for a second, and then back to amber.

And, it was like it would never get a full charge as I left it plugged up for a bit after that.

But I can get a full charge on my regular power outlet charger.

Probably nothing to worry about as I will only use the car charger in extreme emergencies anyway, but I was just curious.

Thanks.