Capacitor recharge rate

• Your capacitor will recharge faster the closer you are to (approximately) 25% of your maximum.
• The recharge rate drops of very quickly once you go below this.

Specifics

Experimental data on capacitor recharge. The blue points are data points from Kivena's experiments. The black line is an equation based on Dust Puppy's research which you can see at the top left corner of the image. The smaller inset graph (orange) shows a percentage of average recharge rate over current capacitor percentage. You can clearly see that maximum recharge is 2.5x the average recharge and occurs at 25%. Click to enlarge

The capacitor recharge rate is a non-linear function—the rate at any given moment depends on how much energy is stored at that moment. Near zero and near full capacity, the recharge rate is very low, and it peaks around 25 percent.

A player by the name of “Dust Puppy” investigated the recharge rate in-depth and published his findings in this thread. Based on his experiments, he suggests that the formula for calculating recharge rate is:

...where:
C is your current capacitor level in GJ.
C_max is your maximum capacitor level in GJ.
dC/dt is your current capacitor recharge rate in GJ/s. (Formally: The instantaneous rate of change of the capacitor charge C with respect to time.)
τ is capacitor recharge time divided by 5.

Capacitor recharge, therefore, peaks at 25%, and the advertised “Capacitor Recharge Time” is actually the time for the capacitor to go from dead empty to 98.7%, assuming no drains or boosts.

Experimenting with this formula, it has been found that the peak recharge rate, without any effect of boosters or energy draining weapons, is indeed at 25% of capacitor capacity.

The formula can be also used to write capacitor level as function of time

where C₀ is capacitor level at starting time t₀ and C is capacitor level at time t₁

The full derivation may be found at http://forum.eveuniversity.org/viewtopic.php?f=222&t=30652 (dead link).

---

Bottom line for EVE capsuleers: remember that the recharge rate declines dramatically once it falls below 25% of capacity. Therefore, if in a fight, leave yourself a margin of safety and consider escaping if it appears that you will soon fall below this amount.

For more on maximizing your capacitor performance, see this UNI class syllabus: Capacitor Management 101