Harting & Helling Janosch MBF5050 Compatible Battery 4.8V 700mAh

Harting & Helling Janosch MBF5050 Series — 4.8V Ni-MH Replacement Battery

This is a 4.8V 700mAh Ni-MH rechargeable battery for the Harting & Helling Janosch parent unit. It fits the MBF5050, MBF5151, MBF4080, and MBF5050 series babyphone systems. When the original cell degrades and stops holding charge, this is the direct swap that restores full wireless operation to the portable parent unit.

• MBF5050 / MBF5151 / MBF4080 platform: These models share the same 4.8V four-cell Ni-MH pack format, connector pinout, and charging circuit. Swapping between models in this series works because the BMS and charge termination logic targets the same voltage ceiling across all three.
• Bench tested on actual hardware: We cycled this cell through the parent unit's onboard charge circuit. The BMS accepted the pack without fault flags, delta-V cutoff triggered at the correct point, and the unit held a stable 4.8V rail throughout audio transmission.
• Post-swap wireless link: After fitting this battery, re-pair the parent unit with the camera unit before assuming anything is broken. Baby monitors lose their stored wireless channel when the parent unit drops to zero voltage — this is a normal reset, not a fault with the battery.

Why the Janosch parent unit drops range after a battery swap

The 2.4GHz radio transmitter in the parent unit is voltage-sensitive. At low charge states, the radio steps down its output power to protect the circuit, which cuts usable range noticeably. A freshly fitted Ni-MH cell that hasn't completed its first full charge cycle will sit below peak voltage and deliver reduced range until fully charged. Run a complete charge before judging whether the battery is at fault. Range restores once the pack reaches full 4.8V.

Parent unit battery draining completely overnight

Night-time monitoring with the screen active is a sustained draw that a 700mAh Ni-MH cell was not sized to sustain indefinitely. The screen backlight is the single largest current consumer on the parent unit. Enable the screen timeout function in the monitor's display settings — most Janosch units support a 30-second auto-off. With the screen off and audio-only active, current draw drops significantly and the pack lasts through a full overnight session.