"Redtag" wrote in message
news
On Sun, 14 Dec 2003 19:18:32 -0000, PJO wrote:


OK, You can either do it properly or do it cheaply. The proper way would
be
to have a proper rated PSU/charger in a proper steel cabinet with the
battery. Quite expensive.

Pete, I am fine with doing it properly - it will still be cheaper than the
£228+VAT that the alarm people wanted!

If I do source the properly rated charger (a 3A one should do it) then how
to I connect this? I would still like to keep the existing 7Ahr battery,
and add this in parallel but if I do this then how to I charge it? I want
to do as little as possible in "their" cabinet and to add my own with this
new battery.

Cheers

Get hold of a Power Supply Unit / Charger that will comfortably take your 17
A/hr battery, and comes complete with a relay switch that operates on mains
failure.

The relay should be wired with the open no voltage contacts connected to
your alarm panel. The voltage side of the relay will be connected from
charger to battery when mains power is present, and then drop from battery
to appliance if a mains failure occurs.

These people should be able to point you in the right direction:

http://www.ktassemblies.co.uk/products.html