Results 1 to 8 of 8

Thread: 12V Car Battery Tester

  1. #1
    vince123123
    Guests

    Default 12V Car Battery Tester

    Hi everyone, hope someone can point me in the right direction.

    I hope to have real life and accurate input for this one, because I won't have a chance to test out the inputs.

    In ICT, we draw out 12V car batteries for use in operations. We may take up to around 20 or so of these.

    I need a method for testing whether these batteries are fully charged; so that the battery store will not give me half charged duds which fail when we are out in the field. They always claim "all are charged", but real life experiences show otherwise.

    Is there a "meter" of some sort that can test capacity of a 12V battery that we can buy? Is this suitable?

    http://cgi.ebay.com.sg/Lead-acid-Bat...1%7C240%3A1318

    Or what I actually need is just a multimeter (which I do have). If so, what voltage ranges would mean the battery is full, and what means its half full/empty?

    I also note from the ebay pic that it may be just a voltmeter - but I was confused to see that the meter reads 10.5V to 12.5V as good, but 12.5V to 13.5V as weak and 13.5V to 15V as OK.

    Urgent input would be appreciated.

  2. #2
    vince123123
    Guests

    Default Re: 12V Car Battery Tester

    Anyone knows?

  3. #3

    Default Re: 12V Car Battery Tester

    To me, that just look like normal Volt meter to me.
    And the 10.5V-12.5V - is refering that the battery is in good condition.
    12.5V to 13.5V as weak, if you look futher down the meter screen, the bottom part is saying charging system. So it is measuring either the charger itself or the battery during charging. If charger is only delivering 12.5 to 13.5V, it is a consider a weak charger for a 12V battery.
    Normally the charging voltage for a 12V battery is 13.5V to 15V, which is indicated as OK in the meter.
    Anyway, if you measure the battery that had been on the shelf for a couple of days and still measure above 12.5V the battery are almost close to 85% capacity liao.
    Last edited by Cursor; 4th November 2008 at 06:02 PM.

  4. #4
    Senior Member Big Kahuna's Avatar
    Join Date
    Dec 2004
    Location
    Singapore, Singapore, Singapor
    Posts
    2,127

    Default Re: 12V Car Battery Tester

    Hm...hope this helps

    9.12 at http://www.batteryfaq.org/

  5. #5
    vince123123
    Guests

    Default Re: 12V Car Battery Tester

    Thanks Cursor and Big Kahuna - I'll read the reference.

    Cursor: Does this mean I can use a normal voltmeter to test whether a 12V battery is charged? So long as it reads above 12.5V I can accept from the battery store? I've read online about testing voltage under a load and no load - does this make a difference?

    I think I now know - the "charging system" part is intended to test the alternator in the car....to see if it is working well enough to charge the battery. I don't require this feature, merely need to test the battery itself.
    Last edited by vince123123; 4th November 2008 at 06:36 PM.

  6. #6
    vince123123
    Guests

    Default Re: 12V Car Battery Tester

    Big Kahuna, 9.12 says:

    9.12. How Long Will a Deep Cycle Battery Last On a Single Charge?

    Is this the correct one?

  7. #7
    Senior Member Big Kahuna's Avatar
    Join Date
    Dec 2004
    Location
    Singapore, Singapore, Singapor
    Posts
    2,127

    Default Re: 12V Car Battery Tester

    Quote Originally Posted by vince123123 View Post
    Big Kahuna, 9.12 says:

    9.12. How Long Will a Deep Cycle Battery Last On a Single Charge?

    Is this the correct one?
    Yes if how long the bat can last you're after......but don't ask me how to calculate as I flung my math in high schewl

  8. #8
    vince123123
    Guests

    Default Re: 12V Car Battery Tester

    Oh no actually I was trying to ask how can we test a battery to determine how fully charged it is.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •