Technical How do you tell if its battery or alternator?

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Technical How do you tell if its battery or alternator?

hixy

New member
Joined
May 22, 2007
Messages
37
basically if i leave car for a few hours and come back to its flat, any asy way to tell without replacing 1? cold and damp seems to make it worse??


cheers
 

Ffoxy

Telford's Own...
Joined
Apr 26, 2007
Messages
13,617
Sounds like battery to me, cold weather decreases efficiency. Can you get a local Auto electrician to do a charge test and eliminate the alternator? Or check the off and on load battery charge and discharge rates?
 

jug

blessed are the apostates
Joined
Nov 28, 2005
Messages
27,935
Location
Durham
could be battery, alternator, or drain.

if you fully charge the battery then drive for some time, switch engine off, then try to start it again, is the battery flat?

if you fully charge the battery then fit it to the car and leave it overnight, is the battery flat in the morning?

do you have a multimeter?
 
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