Using Ctek recovery mode insitue

[uk_friendly_fire]

Hi Ctek chargers can be used connected to the car battery whilst it's still connected to the car's electrics. Older batteries can be desulfiated using creks recovery mode however I read that the charger can produce up to 16v in this mode.
Two questions:
1) Does anyone know if that high a voltage will damage anything?
2) Has anyone used the ctek in recovery mode whilst the battery is connected to the car?

[Drummond]

As per CTEK, the recond mode should not be used for AGM batteries. Check if your battery is of that type.
https://ctek.my.site.com/faq/s/article/H...9594652697

I'd rather not use it on battery connected to the car anyway. The strong pulsation might confuse the car inbuilt battery management.