last year bought Honeywell ADE LCD Accenta from you website want to add:

Honeywell Hard Wired Carbon Monoxide Alarm

Honeywell Combination Optical/Thermal Smoke Detector (58°C~)

Honeywell Combination Rate-of-Rise/Thermal (58°C)Smoke Detector.

 

are the above compatible and do I need bases for the fire detectors and can I add a 12Volt 7Ah battery instead of the 2.3Ah exernally (outside of the panel)

All three Honeywell fire sensors are compatible with the ADE Accenta control panel but will need either a latching or non latching base.

Although you can add a 7A/h battery I do not reccommend it as the panel would struggle to charge it when fully depleted, and being outside the panel it is not tamper protected and thus could be removed.

I would not mount a battery outside. Yes you could do this it would 'work' but is not advised. If you require more standby time i would fit an additional PSU ie

http://www.securitywarehouse.co.uk/catalog/elmdene-1381n-p-606.html

 

connect all your powers to this and fit an additional 7A/h in this enclosure.