Battery Model Defaults

Dear Paul,

I was hoping to get some clarification on the default values that populate for the battery model in the desktop app.
- Are these values from a specific battery manufacturer/model, and if so where could I find this data and information?
- When I'm trying to model a specific battery (ex. EVE's 3.44MWh Energy Storage System), the battery datasheet does not contain some of the information that is required for the model (voltage-discharge curve, cycle life data, internal resistance). Do you expect that this data is usually accessible on a datasheet or should users rely on the applicability of SAM's underlying voltage/lifetime, etc. default models where manufacturer datasheets are lacking?

I greatly appreciate the expertise you have shared thus far!

Best regards,
Trinity
 

Hi Trinity,

The default values for the different battery types (or chemistries) in SAM are for a typical battery of that type. The parameters come from different sources and do not represent a specific manufacturer's model of battery.

As you note, unlike for PV modules and inverters, the information provided by manufacturers on battery datasheet is not standardized across the industry and is not sufficient to fully specify the battery type in SAM. For most batteries available on the market, one of SAM's default battery types should adequately represent the battery's performance characteristics for the type of simulation SAM is designed for.

Best regards,
Paul.

Hi Paul,
Thank you for the details - are these typical battery parameters an averaged value across many sources or simply just values taken from multiple sources?

Further, the documentation mentions that the lithium-ion chemistries have default values originating from Lindon's Handbook of Batteries, but I was not sure where the lead-acid and flow battery values come from if you have any insight on this.

Thank you for the clarification on the models! If only there was some kind of datasheet standardization for batteries.

Cheers,
Trinity

Hi Trinity,

The battery parameters for each battery chemistry are values taken from different sources to represent a realistic battery, not averaged from different sources.

There is some discussion about the source of default lead acid parameters in DiOrio, N.; Dobos, A.; Janzou, S.; Nelson, A.; Lunstrom, B. (2015). Technoeconomic Modeling of Battery Energy Storage in SAM. 32 pp. NREL/TP-6A20-64641 ( PDF 2.6 MB ), for example in Section 3.1.1.

Best regards,
Paul.

Hi Paul,

I appreciate the clarification - thank you for the quick response!

Cheers,
Trinity