Peugeot 205 - Battery or Alternator ?

Honest John Back Room » Technical matters
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Mon 23 Jul 2007 13:17
Peugeot 205 - Battery or Alternator ? - geoff1248
Our old faithful Pug 205 has started to become not so faithful and doesn't like starting in the morning, but then do any of us. So I need to find out if the problem is with the battery or the alternator. When I turn the key there is nothing, not even a click of the starter. I put the battery on a booster charge for 15 mins. and she starts fine and runs for the rest of the day without problems restarting her. Next morning--dead. So, how can I tell if the battery is shot or if it is the alternator failing to charge the battery?
Ta

{Car details added to attract the attention of Peugeot owners - DD}
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Mon 23 Jul 2007 13:54
Peugeot 205 - Battery or Alternator ? - kithmo
If it starts ok during the day then the alternator is doing it's job and the battery is duff. Typically a duff battery may accept a charge but not hold it overnight.
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Mon 23 Jul 2007 13:56
Peugeot 205 - Battery or Alternator ? - kithmo
Forgot, also check that nothing is draining the battery overnight, maybe disconnect it even (make sure you have the radio code).
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Mon 23 Jul 2007 17:08
Peugeot 205 - Battery or Alternator ? - yorkiebar
Easiset way to check a battery in suspected poor condition.

At night after driving, remove the negative terminal (assuming you have the code for the radio etc). In the morning, re connect it and when you go to restart it will either have power or not.

If it has sufficient power then the battery is doing ist job (holding a store of electricity). If it has insufficient power then the battery is at fault.

Assuming the battery is ok, the alternator is a little more difficult to test. The choice is either the alternator is not charging enough or something is draining the power.

So, if running the car the battery stays charged (dissonnecting overnight) then its likely its charging ok and you have a drain on the system.

If it is losing power this way and only lasts for 2 or 3 days then its likely the alternator isnt charging enough. hth

It would be interesting to see what a voltmeter records with the battery too. When its just been driven, when its been stood for over 2 hours, with it running at idle and at 200rpm with and without electrical load, and voltage readings at roughly 2 or 3 hour intervals after drivnig. It isnt an exact test of an alternator but its a good laymans test.
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