PowerSupply

Power supply

Requirements for the charger:

Only interaction: turning on or plugging in the power supply; all wires remain connected all the time
The devices can be turned on all the time, independend of whether the power supply is plugged in. When it is not, the devices are supplied from the battery.
When the power supply is plugged in, the charger can remain connected to the battery for an arbitrary time without damaging the battery.
When the power supply is not connected, the battery is not discharged by the charger.
The battery is charged to at least 50% (better: 100%) in one night.
A short-circuit does not damage the charger.
When the battery is not connected, the charger does not damage the devices.

Values: