If it was very low, it will take a good couple of days on a small trickle charger, it's limited to what it can supply, it will probably be ok tomorrow. It will almost certainly be warm if trying to charge a flat(ish) battery. It looks ok though.
My Accumate can take 3 days to go to "green" on the Maser depending on how long it's been left (took a day on the Aston)
The Maserati branded charger IS the XS0.8 CTEK unit but at the price of the far superior 5 amp CTEK item (XS5.0). The XS0.8 charges at 0.8 of an amp whereas the other at 5 amp so obviously takes longer to charge a flat battery. The 5 amp item will assess the condition of the battery and can recover a dead one with it desulpating programme.This does indeed look like the CTEK unit, minus a few LEDs. Likely the tiny unit XS 0.8.
I have one of these used to trickle charge the car when not in use. Also bought the bigger unit XS 5.0 to revive the battery in the 3200 which seemed properly FUBAR. This unit does motorbikes too so useful on my Vespa (now gone). Not too expensive, especially compared to a a new Bosch