I used to use CTEK chargers, but lost faith with them 10 years ago, after having multiple failures across three different models. I switched to the Optimate chargers and use them ( different models ) on the bikes, garden tractor, Volvo and the Plus Six. The chargers are specific to the type of battery fitted. So far no issues, but I am not a battery expert in any way, so maybe I have just been lucky with them. The issue of the "modern" 12v car battery types failing suddenly is always at the back of my mind though. Our Plus Six is coming up to six yrs old, so I think this winter its due a new battery. The original fitted is a Yuasa, so do I change brands or keep to the original??.
Batteries don't fail suddenly per se, they typically loose their capacity slowly and steadily over a period of time dependant on how well they are looked after and/or used. The sudden findings that a regularly used car starts one day but not the next is usually down to that car starting easily, masking how little capacity is left and typically happens at the onset of winter as cold start oil temperatures drop. Regular monitoring of a fully charged batteries standing voltage at least 24 hours after last use or charge will be a good indication of a batteries ultimate life. 12.2 volts or less measured at the battery and the end is nigh. Another pointer is how quickly your smart charger reaches the fully charged indication, with minimal capacity left this is going to be much sooner than when new.
FWIW I recommend Hankook batteries. Have used this south Korean brand for many years on cars and boats with great longevity - why pay more as they say.
