strange charging behavior

I have the charger for my BMW motorcycle to buy via the vehicle socket easy to load it. For this the device must be capable of CAN like this one.
When pressed on the Mode button, the display also flashes and thus signals the CAM mode. As far as OK.
My battery is 1 year old, fit and the bike is moved daily.
Nevertheless, I have tested the charging time: and behold, the battery should be almost empty?
Also 24 on Loader brought no change - voltage at the battery is loud BMW board computer 100% OK.

Then I tested the device on Corsa my girlfriend - because the battery is 5 years old and the car was not moving for many weeks. The charger immediately shows 100% charge on and after about 1 hour, it switches off (red LED on)?

The behavior is very dubious - if I once more time I watch all times with an ammeter on.

Possibly I've got a Monday device - so far I could not confirm any case no successful charge. If at least the CAN invite motorcycle goes I keep it - I just hope that with the 1.2A the Batt can not be overcharged. Shutdown does not do it at that so of its own accord. For this, the BMW has certainly times are 6 weeks and the starter must be weak - then I will again load and check for 1 day. The LEDs have in my device in any case not be indicative of the charge state.