Yes I have a voltmeter. I will test today. Actually, the fan does not come on. Light stays solid yellow. After the computer went into sleep mode over a year ago, the battery hub and charger continued to go through the proper charging cycle. After about a year that stopped. Assuming I have to rebuild the battery, what is the tear down process for the hub? I have already removed the core electronics from the hub. It seems that to remove the battery harness, I first need to remove the nut on the rear side of the hub and then tap the core out of the bearing. Would that be correct?