After losing a couple of batteries last winter in cold sheds, I decided to invest in some trickle chargers, which I left on all winter in the thought that this would keep the battery alive. However, once again, I have a battery which will not turn the engine over. It shows fully charged on a charger, and on my cheap battery condition meter shows all greens/good. But the tester at the battery shop said it was dead. Did I do the wrong thing with the trickle charger ?