One question on the SiO2 to which I cannot find a good answer: What is the charge current limit? On good quality AGM (Lifeline) you can bulk charge, voltage controlled, with no current limit. Practically for Lifelines it will take about 0.5C for about 1/2 an hour, then go down to maybe 0.3C for a couple of hours, then taper slowly to 0.02C at the end of charge. Much of the SiO2 advertising says "charge faster than AGM" yet their charge limit seems to be 0.3C. That is not faster than AGM, and requires the charger be current limited which leads to power management problems.