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.
Apologies Dave I missed your post as the page had turned... (-: Also sorry to read of your CTEK disappointments, though I have had no such issues with mine as my seldom used cars were until now permanently connected to their live CTEK chargers when not in use, and as such both cars never failed to fire up when required over many years...The Morgan with it`s old style wet lead acid battery and matched CTEK, and the 2012 stop/start facility equipped car with it`s AGM battery and matching CTEK AGM float charger/conditioner..
As for practical experience of sudden battery failure, I suspect that is a rarity indeed, and may often as the result of misdiagnosis, been there and done that myself, the fault being down to a cruddy connection hiding under a cap type terminal that was not loose..
HOWEVER in the case of my recent AGM battery failure, that the 2012 car had been running well for a journey time of circa an hour in daylight with headlights or air con in use, it came as a complete surprise to shut down the engine for a max of 10 minutes, then request a restart to see the dash go blank, untill the ign key was released to the stage where the dash display returned and circa 11 volts was measured along with as expected way too many fault warnings to make any sense of... All of which suggested a cruddy connection somewhere, and as the O.E. battery was replaced circa four years previously when all added together a cruddy connection to the primary ECU was my general expectation.... As up until that time I had not come across a battery with an internal and seemingly INTERMITTANT connection between cells.....Whether that might in any way be an AGM related issue... or not.... I have no idea, though that battery did fail when connected to a load testing device.
As ever I rely on those with more practical knowledge or education than I in such cases... to determine that AGM batteries may present a different set of charging challenges, and causes of failure.... Though having typed that my 2012 car`s seemingly original AGM battery lasted for circa 9 years, until I forgot to connect it to it`s CTEK charger and it failed to start the engine after only 8 days or so, indicating that the battery`s ability to hold charge had likely diminished with the passage of time, which is to be expected..
Replacing a battery on an irregularly used vehicle and or one that may note be used over winter, just seems to me like a reasonable form of insurance, but even that is not guaranteed to avoid a fail to start situation. as for sticking to the same proven brand.... Yeah, well risk management and cost cutting can in time lead to increasing failure rates in once trusted brands of anything.... mare is the pity.
Wishing you the best of luck in your choices. Even with my new battery in the 2012 car, I suspect I will be driving it with my fingers crossed for a while yet before I regain some sort of confidence in it`s abilities...!
