100% agree
OK,
I'm thinking that given all the variance you might want to either do some experimenting with different loads and time them or just take a weighted average (SWAG).
If you think about it for a while you will conclude that generally you have some sort of "standard electrical load" along with the high amp loads that only happen infrequently and of short duration. With that said the usefulness of the Peukert factor is of less import than say in a system where the loads are both big and small and have no predicted frequency of occurrence.
Another way to say this is imagine the perfect battery monitor and the just average one. Now start your motor by sucking out 100 amps for 3 seconds (0.083 AH). The perfect battery monitor will subtract whatever is does and report that while you are cranking for that 3 seconds you have a significantly lower SOC. Once you remove the load it will report that almost nothing changed as far as SOC is concerned due to the very short duration of the very high load. The average battery monitor will completely miss the start cycle and just report the SOC as if the engine never started at all.
So what is the difference except the guy that bought a fancy state-of-the-art battery monitor is out more $$$$?
I'm thinking that your "best guess" is going to be OK given how we use batteries on boats. YMMV
There is very little value in having extremely accurate PE numbers, because that will change as the battery ages. Plus, what use is it? You are always minimizing your loads while sailing, and the meter with PE defaults loaded in will give you plenty of indication that you are flattenining your battery.
Also, when you start your engine, there is a huge brief load. But then you are charging right away.
As a general rule, you have a fridge (or 2) plus instruments running while you're sailing. Throw an ice block in the freezer. This will make more difference than accurate battery monitoring.
. I will set my monitor at 1.20 and look forward to launching for the season May 1.