I purchased eight Trustfire 10440 blue batteries (the ones that appear most popular on this forum). Two of the eight batteries don't work in the cars because the positive terminal repels the magnet that normally holds the positive end of the battery. The battery works fine in the transmitters. On closer inspection, I noticed the appearance of the batteries are slightly different. Both "bad" batteries are like the one on the left, while the six "good" batteries are like the one on the right.
Yes, I have a whole bunch of them. Well at least you only got two! They will pop out of the car, but work in the controllers as you said. I did find a solution by soldering a piece of 10 thou. steel like the lane change plate to the battery. Be careful not to much heat or you might damage the battery. I have a photo in another thread some where.
I think we decided that the problem must be that the battery nipple is non magnetic, i.e. probably stainless steel. Don't have an answer at present other than soldering a steel tab/washer to it.
Just 2 people have had this problem as far as I know.
