Yes. used batts are not worth much at all, No one knows whether they were kept fully charged or left to sit and sulphate, severely shortening there life, the hawker batts are only stated by the manufacturer for a 3 year life, We all know they will go longer, but used batts are a crap shoot even these, I have spoken with the tecks at hawker 3 times since buying a new set of these, and they should be brought to a full charge when installed and yes there are specific charge rates to fully charge these batts, Then and only then a maintainer will work keeping them up, the problem I see with these awesome batts is that they were probably never maintained properly because they are different. I will say Mine start my 925 like its a warm summer day at 20 here. If someone buys them they should get them to a full charge making sure they have a charge rate of at least 13.6 volts, then purchase a quality maintainer desulphator. I know so many people who have new batts of any kind and after a few months do not understand why the truck did not start, first they were not fully charged when purchased, second they need to be maintained on a charger, they are not magic, they lose power every day when not used, and short runs may never charge em and actually have them get weaker and weaker and sulphate up. fyi for some basics,