# Specific energy vs Specific power in batteries

When looking at the Wikipedia page for Lithium-ion batteries, one can see that there are some technical details such as Specific Energy and Specific Power, but I don't know how to connect them.

For example, one can see this:

Specific Energy: 100–265 Wh/kg

and

Specific Power: 250 - 340 W/kg

According to the theory, power equals energy divided by time; i.e. 1 W = 1 Wh/t. So can guess that t is the discharge time. Li-ion batteries usually have a discharge rate of 1 C, which means that the battery would be discharged in around one hour. Looking at those numbers, it doesn't look like my logic is correct, therefore I would like to know if this is the case or if those numbers don't really match?

• It's not theory: it's definition. Energy = $\int Power*dt$ . As the battery discharges, it's internal resistance changes, so voltage changes, and so on Feb 1, 2018 at 19:16
• The power is instantaneous power for a fully charged battery. That rate can not be sustained for a whole hour. Based on the energy you might expect roughly a half hour at that discharge rate. Feb 1, 2018 at 19:23