Trojan got caught with their shorts down around their ankles. This is why I am so steadfast in not finagling with reality. Cyclable batteries develop heat when charging or discharging. The active mass involved versus the radiation square inches determines a manufacturer's charging recommendations. Plate thickness determines the characteristics of a battery - are the plates on a T-1275 the same thickness as the T-105? I believe Trojan only upgrades the paste on their industrial elecro-motive batteries. The 105 and 1275 should have the same paste formulation applied to them.
At 50%SOC total current to achieve 14.8 volts would tell the story.
It is extremely necessary when first charging a battery at "VMAX" for cell to cell temperature and cell variance monitoring. A 1c/min rise must be monitored closely and current reduced if the cell temp achieves 40c.
I'll throw n a tidbit. Charge rejection high impedance is the mark of a poor quality battery. This is a somewhat complex calculation involving weight, plate thickness, and ampere hours at the 20 hour rate. Two evenly matched contenders, the one with the lower impedance will be the winner. But hidden things like plate count can obscure the test. Par for par, a Trojan T-105 will charge easier than a US Battery, Johnson Controls battery or Deka. Such is the nature of deciding which is the bigger inhibitor to marketability: Price or Performance.
