Diagnosing Car Battery Issues
Discussion
I bought a 11 reg Mazda 6 in July. August it wouldn't start. I replaced battery, which solved the problem.
In April it wouldn't start again. Alternator was tested via the OBD port and the reading was spot on. I charged the battery which solved the problem (although the needle barely moved on charger). Today, almost 1 month to the day, it wouldn't start again.
Driving is mainly a 20 mile round trip 2 or 3 times a week, with the odd shorter journey in between so driving usage is unlikely to be the issue.
Unsure of what to do next, but I need to work out if it's a duff battery or a parasitic drain.
I have a receipt and warranty so returning (to Halfords) is a possibility. I have a multimeter, but no idea how to use it.
Any recommendations of things I can do myself, or should I just take it to a local garage (I have a decent indy nearby) or call a mobile auto electrician?
In April it wouldn't start again. Alternator was tested via the OBD port and the reading was spot on. I charged the battery which solved the problem (although the needle barely moved on charger). Today, almost 1 month to the day, it wouldn't start again.
Driving is mainly a 20 mile round trip 2 or 3 times a week, with the odd shorter journey in between so driving usage is unlikely to be the issue.
Unsure of what to do next, but I need to work out if it's a duff battery or a parasitic drain.
I have a receipt and warranty so returning (to Halfords) is a possibility. I have a multimeter, but no idea how to use it.
Any recommendations of things I can do myself, or should I just take it to a local garage (I have a decent indy nearby) or call a mobile auto electrician?
Using your multimeter, set to DC Volts, with the engine idling measure the voltage across the battery terminals. If the alternator is working correctly the voltage should be 13.8 - 14.4V.
With the engine off, if the battery is in good condition and 100% charged it should measure circa 12.6V with no load.
With the engine off, if the battery is in good condition and 100% charged it should measure circa 12.6V with no load.
Thanks for the advice. I was a bit apprehensive (and clueless) about using the multimeter. Which unfortunately my isn't very good either, it's analog and I have to use a 50 volt scale. However I tried a things and made progress.
Testing the battery before charging showed 11 volts. After charging a little over 12 volts. With the engine running it barely moved upwards, maybe half a volt, nowhere near 14 volts.
So it looks like alternator, I'll get it to the garage on Monday.
Thanks again.
Testing the battery before charging showed 11 volts. After charging a little over 12 volts. With the engine running it barely moved upwards, maybe half a volt, nowhere near 14 volts.
So it looks like alternator, I'll get it to the garage on Monday.
Thanks again.
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