@HKJ: I do have the voltages during charge and discharge and can calculate the energy efficiency, if I can find the time I may do it.

Calculate ? I wonder how you could do this as voltages are varying during charge and discharge in fonction of the time at a non linear rate ?

Could you explain how should you calculate the energetic efficiency ? What are the formulas you intend to use ?

I have log points for each second, it is easy to calculate power for each log point and then sum power*time. This would give my total charged and discharged energy.

My logfile looks like this (i.e. I have already done the calculations, I just need to collect them from a couple of files):

time SMMeasure SMSource SMOhm SMW SMAh SMWh

0 1,028179 0,99999 1,028189 1,028169 0,000257 0,000264

1 1,044294 0,999991 1,044303 1,044285 0,000535 0,000555

2 1,061145 0,999992 1,061154 1,061136 0,000813 0,000849

3 1,078734 0,999991 1,078744 1,078724 0,001091 0,001149

4 1,096882 0,999992 1,096891 1,096873 0,001368 0,001454

5 1,115237 0,999992 1,115246 1,115228 0,001646 0,001763