Ok, there is an effect I can never recall the proper spelling of which says THE FASTER you discharge a battery the faster^2 it runs down
So a battery that holds 220 amp hours at the 20 hour rate (11 amps) may only hold 150 at say 20 amps. or 300 at 5 amps.
This is why a Group 24 battery ( roughly 75 AH at teh 20 hour rate) has over 100 amps at the "one amp" rate.. (Wal*mart) they slowed the discharge so as to make the battery LOOK better on the spec sheet.. We who research are not fooled.
So I am assuming the person pushing parallel. Did not double the load else his result would be different.
I have the bandwidth today (And tomorrow) so let me research...
Explanation better than mine at Battle Born Batteries dot com Peukert's law WikipediaI can spell it well when I'm looking at the above URL :).
