BCI (battery Council International) capacity testing RC (Reserve Capacity) is the minutes a battery can give 25 amps down to 10.5 volts. This is where I get the 25 amps. Note the charts that say 10.5 is fully discharged will be very close to 12.06 as 50%.
Yes the Trojan numbers seem to be a bit lower than the generic charts for resting voltage. This is what you should follow if you have Trojan Batteries and ignore the rest.
http://www.trojanbattery.com/tech-support/battery-maintenanceI looked for a US Battery chart to no avail.