Nodes are powered by either rechargeable internal Lithium-ion battery packs or replaceable non-rechargeable batteries - the design and the specification of the node will determine what battery technology is used. The battery life of a node unit is a critical consideration in the design of a node project; this is because once the battery runs out on a node, the data that has been collected is no longer stored on the solid-state hard drive and all data recorded since it was deployed on the sea floor will be lost. Therefore, a node with a 30-day battery life must be deployed, record data, be recovered and reaped within that 30-day period. This also ties in with the number of nodes that are to be deployed as this is closely related to battery life too. If too many nodes are deployed and the OBN crew’s resources are not sufficient to recover these in time or external factors such as adverse weather limits recovery operations, batteries can expire and data can be lost. Disposable or non-rechargeable batteries can also create a significant waste management issue as batteries must be transported to and from an operation and the drained batteries disposed of by a licensed contractor ashore.