Calendar vs Cycle Battery Degradation

Hi Paul,

Please find the attached .sam file. I'm using SAM version 2023.12.17.

Regards,
Yashwanth

Hi Yashwanth,

For the Li-ion LMO/LTO battery type's lifetime model, in any given time step:

Battery Relative Capacity to Nameplate (%) = 100% - Battery Relative Capacity to Nameplate Cycling (%) - Battery Relative Capacity to Nameplate Calendar (%)

The source code for that calculation is in the 'lifetime_lmolto_t::integrateDegLoss()' function here: github.com/NREL/ssc/blob/005b77b3c9fbe73c70806cebe631c30adf169433/shared/lib_battery_lifetime_lmolto.cpp#L133

In your case, the battery capacity starts at 100% and degrades to 94% at the end of the 15-year analysis period, so the battery does not experience much degradation.

Also, because the battery bank replacement option on the Battery Life page is set to "No replacements", the battery degradation has no effect on your simulation results the cost of battery replacement, but may have a small effect on simulation results if you are using the Self Consumption dispatch option or modeling grid outages. [Edited 5/10/24]

Best regards,
Paul.