In the instruction manual, no information appears on the charging time of the parent. (- Flashing red - low battery; - red continuous light - charger connected - charging) Normally, the red light should go out when charging is complete (automatically controlled), which it does by 5, not after 10 and not after 20 hours !!! In unregulated charge compulsory there is no indication to the maximum charging time. A new battery (after repeated overloading) costs about 10 euros. According to my calculation, the charging time should not exceed 1.25 - done 2 hours otherwise take the battery damage. (400mAh (battery) divided by 450mA (charging current) times 1.4 times equal to 1.25 hours charging time (rounded up 1.5-2 hours) How should the average consumer of the XYZ learn if not from the manual ...?
Otherwise ..... baby monitor: NEVER reach 300 m and sound somewhat muffled. If the battery problem is resolved, the unit is in this price range but highly recommended. All devices more than 50 or 100 Euro have Schnullifunktionen that nobody needs!
Addition: Even after repeated request to battery / AC adapter / manual customer service is no reaction. Presumably it does not need.