Janchee
Senior Member
A lot of MXS 5 owners have said the same and if I recall correctly the MXS 7 and 10 do not exceed 14.8 v in any of the settings but the risk is not only to any of the VRLA batteries but to the sensitive electronic components of the car, with a healthy battery, the initial desulphation mode is only momentary but if the charger detects any perceived desulphation and as you can see from the chart I posted earlier, desulphation at 15.8v can last for up to 8 Hrs. In everyone's MB Owners manual the guideline is not to exceed 14.8v This is the spec of an MB branded CTEK charger.
Just put my MXS 5.0 on AGM mode for the E-class. I don't think (any?) are still fitted with Lithium-ion batteries now, but here it is from my owners manual. Says no more than 14.8v for AGM, and 14.4v for Lithium-Ion. It doesn't even spend a nano-second on de-sulphation phase (1) and goes straight to number two. Although, it should be easy for CTEK to correct the manual ... Many online forums discussing this stupid print.
Even though, I 'unlock' the car so the lights are on (i.e. a bit of drain just-in-case), and then turn on the trickle charger. Used many times up until now and seems OK I stay with the charger for 10 minutes or so and then go back each hour to check.