I have a battery (Autozone)about one year old that I'm having a problem with. It registers about 12 volts on my test meter but does not put out any power. i took it to Autozone and had them test it it registered 12 volts and showed the battery to be good. i've tried it on several things but it is not putting out any power. the last one i tried it on was a small winch on my trailer. i hooked it up with the clamps from the winch and it would not turn the winch. I connected another old battery to the winch and it worked great. My connections are clean and good because other batters work on the smae machines. Any ideas?