Elon Musk has done it again. He said Battery Day would be insane and it was. His new 4680 battery system gives Tesla a 16% range increase and will cost less than half. I can’t wait to put a set of these “bad boys” into the ESPcat (Electric Solar Powered Catamaran). So how did Musk and his team do it? Was it the highly touted solid state lithium-sulfur battery?* No!
The new battery doesn’t seem all that big a breakthrough until you begin to add up all the bits and pieces. The 4680 is bigger, 46 mm x 80 mm tall. So why didn’t they always make bigger batteries. They couldn’t make them bigger because they would get too hot with the old design. By introducing the patented tabless construction, the new battery has less internal resistance so is more efficient generating less heat. Even though the 4680 stores 5 times the energy of the 1865, the amount of heat generated is small enough to be dissipated safely.
Tabless construction, means fewer manufacturing steps. Think of the massive energy storage production versus time. It takes about the same amount of time for a robot to stomp out a fat battery as it does to stomp out a little battery with only 1/5 the energy. But wait, there’s more!
Tesla has is doing something simple but special. The new battery packs are going to be part of the structure of the frame. It is like honeycomb construction except instead of honeycomb, you have fat battery cells. This means that tesla gets to throw away all the extra cost and weight of the steel members that make up the current chassis.
I see no reason why the same idea can’t be used solar-electric boat design. Why not have the battery pack be part of the boat structure. Imagine a catamaran with a structural member made of battery cells, holding the hulls together.
There are additional breakthroughs as well including improvements in cell chemistry but that is just icing on the cake. Electric cars, and by extension, electric boats, are really going to take off now. Bring on 2022.