I've tried using the freezing and heating method, but it did not work. Here's a method of bringing them back to life by zapping those shorted crystal dendrites away with too much current and/or voltage. You can use a welder as a power source. You could also use a car battery, a DC powersupply, or almost anything with some voltage. Make sure to wear eye protection, match negative with negative and positive with positive, and zap it for 1 - 2 seconds a couple of times and it should be good as new. I 'd hook up the negative side to the battery first. Then touch the positive to the positive side. You want to see some sparks - it is normal and not to worry. If you're not sure which is positive or negative on the battery, you can use a volt meter - use the meter also to measure the almost immediate result before and after the battery has been zapped. Repeat the process if the battery is still not holding charge, but I can assure you that you will see a big difference almost right away. The battery companies do not want us to know about it so they can continue to rip us off. Good Luck!