# Current in a Lithium Ion Battery

I am trying to find the current transferred to the anode and cathode of a Lithium Ion Battery at different voltages. I know the temperature (approximately) of the battery, the battery's starting voltage, the voltage at 30sec intervals of a constant power discharge (from which current can be deduced), the dimensions of the battery and the initial amount of charge in the battery. What could I do to find this current transfer?

• Use ammeter instead? Sep 14 '18 at 20:55
• Do you mean "current" (e.g. mA) or "charge transfer" (e.g. mAH)? Sep 14 '18 at 21:53
• Current so it would be mA and can't really use an ammeter because that would require me opening up the battery which is kind of hard at this stage. Sep 14 '18 at 22:22

Power is the energy transferred per unit time ($\frac{J}{s}$) and is determined by the potential drop (V) and the current (I) at a given point in time as $P = IV$ so to get the current, solve for $I=\frac{P}{V}$. This gives you the current at a given point in time.
Your question has a few points that might be worth addressing. As Dr Moishe Pippik commented, "current transferred" is a little confusing, either instantaneous current ($I$), or total charge transferred ($Q$), which is the current integrated over time: $\sum_{t} I(t)\Delta t$ in your case. So if what you really want is the total charge transferred, you would have $Q = \sum_{t}\frac{P\Delta t}{V(t)}$. Strictly speaking you should exclude t=0 point to avoid double counting.