Cordless phone battery draining problem?

There are many instances of battery draining but most of the time it is due to poor quality of battery including those that are in shelves which have lost the charge capacity.So here are some tips

Unless the phone is showing any malfunction we cannot confirm unless a drain test is taken in the standby condition of the phone.This must be quite negligible current about few mAmps . If there drains is more check for leak in the battery source to the IC feed, a possible zener shorting or a capacitor leaking.
However if the phone is using up power on talk time , it can be due to drain in a functioning circuit which will be hard to find , but check for unusual heating in any components.
If there was leak in the board this must be ccleaned out well with petrol and may be insulated with varnish.
If however the phone works fine then it can be the fault of the battery itself as it could have developed reverse polarity.
Let the battery drain off fully and recharge, if possible a jump charging with an external voltage might sometimes cure this issue.
If not change the battery with the correct current rating.