DRAFT

====== secessus' power system model ======

{{ :opinion:frater_secessus:model.png?200|}}

Heads up:  this tool is intended to simplify my life when helping people with power setups, not to be Holy Gospel.  Do your own homework. 



===== assumptions =====


The model makes several assumptions: 

  * Lithium can be discharged to 80% DoD, lead chemistries to 50%
  * it uses nominal voltages (12.8v, 12.0v, etc)
  * it assumes LiFePO4 rather than Li-NMC, so use Watt-hours for sizing given the option
  * it uses [[electrical:solar:pvwatts|PVwatts]] for insolation averages (hours of full sun equivalent by month
  * assumes a steady level of current from alternator, so for short drives use rated current for DC-DC and [[electrical:12v:battery_capacity|0.2C]] for direct chargining.  For longer drives use maybe half of that (0.1C)



===== source =====

the [[https://docs.google.com/spreadsheets/d/1n7qiftVYoKvHIrFqQ60G64kiqI14kuXj2oQ2WcBn7yE/edit?usp=sharing|spreadsheet is online]] in Google Docs.  Copy/download if you want to play with it.  Areas that are editable are in green.  


I don't intend to make it particularly friendly, since I am the intended audience.