[moldcad]

OK, so - in spite of so many positive feedback for the CTEK - I purchased the Bosch C3 tender (50% cheaper), and have just successfully completed topping-up my R's 69AH EFB battery (it needed charging badly, as my wife - using the R as her DD - only drives short distances in the city). I used "Mode 3 | 12 V (14.4 V / 3.5 A), suitable for batteries with a capacity of more than 14 Ah in normal condition".

However, I need advice on which mode of the Bosch C3 to use with my M235i's VRLA/AGM battery. Should it also be mode 3, or "Mode 4 | 12 V (14.7 V / 3.5 A) suitable for batteries with a capacity of more than 14Ah in cold condition or for many AGM batteries"? But then, how do I know whether my VARTA 80 Ah VRLA/AGM battery in the BMW belongs to the "many AGM batteries" mentioned in Mode 4 description for the Bosh C3 charger? And using higher voltage and current then necessary can be destructive for any VRLA battery - AGM or not - especially when the ambient temperature is what we have now (well over 30C)... Please advise; TIA.