Picked up an XG-A with power winder at yard sale last weekend in exceptionally good shape, inside and out, and hopefully will function with proper battery. Sure looks like power winder needs the cap off to function. However, there is no battery in XG-A nor a cap for it. If camera is working, probably would use it without the winder, so I'll need a battery cap. Is it a standard size? BTW I've been a long time Minolta shooter. Bought my first Minolta Autocord when they arrived in Boston circa 1955; later added two other of related models. Had various Hi-matics model as car camera. Any help you can offer, re XG-A battery, will be greatly appreciated.