I have just purchased a phone plugged it all in have you to wait till batterys have charged for it to work

Mostly both mobile and standard cordless phones will work briefly when the batteries have been on charge quite a short while. The longer they are left on charge the longer they will work for.

The standard cordless phone charges at a very slow rate because it spends most of it's life sitting on the charging cradle but a mobile phone charges much quicker in order for the phone to be more useful, consequently once charging is well underway a mobile phone can be used as long as the charger is left plugged in.

With a new phone and batteries it is better for the batteries to be left alone to fully charge before use. The first full charge usually doesn't last as long as specified but after the batteries have been discharged and charged a few times the full capacity should be achieved.

Usually you need to wait about 15 hours for the new phone batteries to charge up.