is my battery nackered?

1. matalan12 L-plater Joined: Oct 2010 Weston-super-Mare Posts: 73 Citroen Saxo VTS 1.6 16v

   #1 8th August 2011, 11:48

   wondering if anyone can help or has had the same problem
   
   very briefly every so often, the battery light comes up on my dashboard very faintly, and then goes off again.
   
   i have a sub and it works fine, but if i drive a long distance say for an hour or two, it has the tendancy to cut out for no reason at all, and then starts to work again.
   
   are these signs of my battery being on its last legs
2. marrygold Regular Poster Joined: Aug 2010 Posts: 330

   #2 8th August 2011, 13:02

   you should get about 15v at you battery when you hold the throttle up abit
   if thats ok and its an old battery just get a new one.job done.
3. user_26101 Regular Poster Joined: Aug 2008 HERTS Posts: 281 cammed and carbbed citroen saxo vtr/s Seat Ibiza

   #3 8th August 2011, 13:21

   not your battery dude! if u light comes up on dash that indicates the battery is not reciving charge! u should get around 14-14.5 on charge it may be an intermite fault with the alternator or even a bad live or earth
4. user_26101 Regular Poster Joined: Aug 2008 HERTS Posts: 281 cammed and carbbed citroen saxo vtr/s Seat Ibiza

   #4 8th August 2011, 13:22

   marry gold is wrong dont just buy a new battery cause the light has f all to do with the battery
5. marrygold Regular Poster Joined: Aug 2010 Posts: 330

   #5 8th August 2011, 13:33

   i did say check the power from the alternator at the battery first
6. user_20683 Saxperience Forum Bum Joined: Jan 2008 Woolwich Barracks Posts: 3921 52 Plate Black 8v R'

   #6 8th August 2011, 14:42

   its a bad earth
7. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

   #7 8th August 2011, 16:33

   Quote:

   Originally Posted by marrygold you should get about 15v at you battery when you hold the throttle up abit if thats ok and its an old battery just get a new one.job done.

   15v on your output is too much & would indicate a knackered alternator,check for corrosion on the alternator connections.Plus get the alternator tested.
   
   
   Steve.
8. marrygold Regular Poster Joined: Aug 2010 Posts: 330

   #8 8th August 2011, 18:28

   13.5/14.4
9. matalan12 L-plater Joined: Oct 2010 Weston-super-Mare Posts: 73 Citroen Saxo VTS 1.6 16v

   #9 19th November 2011, 12:57

   right so finally got round to checking it after a long drive on thursday, and again the sub cut out on me after about an hour and a half of driving. also, was booting it quite a bit last night and the battery light was coming on at 110.
   
   so here are the readings that i got.
   
   battery is sat at 12.5v
   alternator is giving it 14.2v
   the alternator alone is 10.5v
   
   so what does all this mean?
10. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

    #10 19th November 2011, 13:36

    Clean the connections on your alternator,it`s probably a bad earth mate.
11. matalan12 L-plater Joined: Oct 2010 Weston-super-Mare Posts: 73 Citroen Saxo VTS 1.6 16v

    #11 19th November 2011, 15:10

    when the engine isnt on, is 12.5v from the battery enough? should it not be more?
    
    for my sub to stop working after driving long distance, could it really be just a bad earth and not the battery/alternator on its way?
12. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

    #12 19th November 2011, 18:32

    Your battery sounds like it`s fine mate,for piece of mind get both the battery/alternator checked free of charge at Halfords.A lot of garages will test free as well.
13. matalan12 L-plater Joined: Oct 2010 Weston-super-Mare Posts: 73 Citroen Saxo VTS 1.6 16v

    #13 19th November 2011, 19:44

    for free, really thats good. how do they test it? if i walk in and say "hi can you test my battery and alternator" lol are they really gonna go yeah sure?
14. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

    #14 19th November 2011, 20:06

    Quote:

    Originally Posted by matalan12 for free, really thats good. how do they test it? if i walk in and say "hi can you test my battery and alternator" lol are they really gonna go yeah sure?

    Yes exactly(no kidding)& they`ll probs use a multimeter or similar tool.
15. matalan12 L-plater Joined: Oct 2010 Weston-super-Mare Posts: 73 Citroen Saxo VTS 1.6 16v

    #15 19th November 2011, 20:35

    already used a multimeter on it. these are the readings i got
    
    battery is sat at 12.5v
    alternator is giving it 14.2v
    the alternator alone is 10.5v
    
    ?
16. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

    #16 19th November 2011, 20:44

    Get a 2nd opinion though mate won`t hurt,if the battery/alternator are ok then i`d start looking at your sub ie the earth.
17. matalan12 L-plater Joined: Oct 2010 Weston-super-Mare Posts: 73 Citroen Saxo VTS 1.6 16v

    #17 20th November 2011, 14:13

    But it can't be to do with the sub I don't think mate because otherwise it wouldn't work ever. It also doesn't explain why my battery light came on when I booted it the other night. Got it to about 110 and it came on. Back down to 80 it went off
18. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

    #18 20th November 2011, 16:07

    As I said get the alternator/battery tested 1st then go from their mate,was everything ok before you fitted the sub?
19. simonwillis1988 Infrequent Poster Joined: Feb 2011 Posts: 174

    #19 22nd November 2011, 20:15

    Make sure the wires to the back of your alternator are secure and check earths, if the light is faint/coming up and going off then it's more than likely a wiring problem, good luck