using a charger like mine, SOC tells the % of charge the battery has regarding what it can take in its present condition. but this does not mean that it is the 100% of what the battery could take when new and in perfect shape. if the battery is sulfated, the original 100% drops to a number that you only could know if you get the SOH.
for instance, if SOH tells you 80%, that means 80% of 12.6v= 10.08v. and that figure is the 100% against which SOC reads the 80%=8.06v. meaning that your battery will not get more than 8.06v even if shows 100% charge. hence the importance of both SOC and SOH.
getting only CCA does not get as far as getting SOC and SOH. thats why Kent in his video was short of the real condition of the battery. volts could give a good figure, but only until checking CCA you can confirm that. if CCA is low you know that the battery cant hold the load. but still is not until you check SOC and SOH that you have the whole picture.