91 twn car EATS batteries

Battery construction could be your problem. Most people don't know that if you use the "side poles" you are connecting to the "top poles" via a wire inside the battery. This allows the primary poles on top to accept a jump to start the car, but the battery won't charge through the side pole because the wire inside is fried. To prove that this is the case, jump from the positive top pole to the positive side pole to start the car. If it works, buy a couple of "adapter" connectors from a parts store and hook your wires to the "top poles" for a permanent connection.