This may sound paltry given Tesla has Gigafactory, which produces batteries including energy storage for a home called Powerwall.
Tesla's power bank uses a 18650 cell with a capacity of 3,350 mAh which is also used on the Model S and X electric cars. Of course the two cars use more than one cell.
Tesla's power bank is priced at US $ 45, more expensive than other types of power bank. It is unlikely that consumers will be interested in purchasing the power bank if it is made by Tesla.