No. 22

Battery Secondary No. 22 is a red plastic cased battery pack that was used in some 700 type push button telephones.  Most of these batteries are now dead or failing and the instructions below advise on how to replace the battery.

The original battery comprises of two cells marked NCB 1572A - Made in Germany.
The battery supplies 4.8 volts - 150ma total output.

Remove the battery lid
The lid is glued and difficult to prise open.  Drill a small hole just under the lid and then use a small screwdriver to prise the lid off.  Once the lid moves, it will come off quite easily.

Remove the old batteries - your have to prise these out - and then remove the lead.

Obtain cells that match the voltage and current criteria and that will fit into the case.  Try to use NiMH batteries. Ensure that the leads are connected correctly.

REMEMBER dispose of the old cells in a responsible fashion.  Most battery companies and council waste sites make provisions, DO NOT put into general household waste...Please!


BACK Home page BT/GPO Telephones Search the Site Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised: February 27, 2019