Your local Fire Alarm Company is another source for the batteries. The batteries in the fire alarm panels are required to be changed out every 4 years. There is nothing wrong with the bulk of these batteries and they will last for years in the RC world. In my flight box I have a 12 volt 7.5 amp hour battery. To use my quick charger I have a 12 volt 18 amp hr battery. I have a cheap Hobbico charger that keeps them charged up. You will also find that even if the batteries do go bad, they make excellent weights for gluing on those doublers. Good Luck, Dave