until 2012, it was, mainly, a (composite) material[1,2] electrode improvement, conforming the composite (Pb/C, as negative) electrode regulations. The Pb to Carbon (mR=mPb/mC) mass ratio, mR is among[2] the limits of the low 5:1 to high 82:1.
Also, latterly, there is a ("composite", internal) device[3] (as another brand, additional) intensification. The device based enhancement resembles[3] by doing an addition of a self-supporting C/super-Capacitor on top (electrically in series) device (internal) connection to the Negative (super-)electrode, via a proton-exchange membrane[4], to the accepted Pb sponge (Negative electrode).
1. The Pb to Carbon mass ratio is about 5:1 to 82:1. The capacitor paste contains lead and carbon in a lead to carbon mass ratio of about 5:1 to 82:1. Hybrid negative plates for flooded deep discharge lead-acid batteries can be made using such pastes in combination with traditional pastes[2].
2. Negative plate for lead acid battery http://www.google.com/patents/CN102576863A?cl=en
3. Noted in the video, after the 38s frame : http://www.axionpower.com/the-battery