Jump to content
Security Installer Community

Battery Standby Time


Recommended Posts

Hi

 

How would you work out how long a battery will last?  I have a 3.2ah battery but id like to know if it will last 24 hours. 

 

http://www.actmeters.co.uk/alarm-advice/fault-finding-a-guide/

 

Using the act fault finding guide i have measured the standby current as 225 milliamps. so 3.2ah/225 = 14.22 hours. is this correct please?

 

 

Edited by Stephen Gibbons
Link to comment
Share on other sites

13 hours ago, james.wilson said:

yes you need a bigger battery. Also A/h is based on a 24hr discharge and only while brand new you will loose 10% in the first couple of years

 

10% i cannot find anything to relate to that figure.

 

All seems a bit confusing. Looking on the net there seems to be a few different calculations.

 

What is meant by de-rating factor and aging factor? 

 

 

Link to comment
Share on other sites

If the battery is a C20 (most likely) then Ah ratings are measured over a 20 hour period. If the battery is discharged quicker than that you loose out on amp-hours.

 

On a bells only domestic you would normally require a standby time of 12 hours with one (15 minute) activation. You also don't want to run close to that figure due to above and also ageing and environmental changes so therefore use the next battery up if within 10%. So you need the standby current and the alarm current for your calculations.

Unless your firing off lots of high amperage sounders, I would estimate a good quality 7Ah battery is required from your standby values.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.