What are the battery specifications?

Vessel comes with a rechargeable lithium-ion battery (240mAh) and on a full charge based on moderate usage can last 1-2+ weeks. If you are a power user, this may not be the product for you. Batteries will always be limited by capacity - a 240mAh battery will last for casual and moderate consumption but if you're drawing all day, every day, it will have its limits.