The OMNeTBattery has a new parameter energyVectorDelta

This controls how often the residual energy values are saved in the cOutVector
Added default value for the OMNeTBattery.ned parameter energyVectorDelta

The default will write the residual energy to disk when it has changed by
0.5 percent since the last write. This will create at most 200 entries per
node which should not be too much