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--- opinion:frater_secessus:sizing-model [2023/07/08 12:41]
frater_secessus created
+++ opinion:frater_secessus:sizing-model [2023/07/08 12:46] (current)
frater_secessus [source]
@@ Line 2: / Line 2: @@
 ====== 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:
@@ Line 10: / Line 17: @@
   * 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)
+  * 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)
@@ Line 20: / Line 27: @@
+I don't intend to make it particularly friendly, since I am the intended audience.

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