# Battery chargers



## teal (Feb 23, 2009)

I have had a Halfords battery charger for some years and hardly used it, it is a 8 amp charger and it does say for PETROL engines up to 2.0.So when my diesel m/h 2.8 jtd battery went dead on me i put it on charge and nothing happened. Yesterday on my car VW engine 2.0 diesel it only just started and made me check the voltage without engine running, it was 11.90 v wow!. Put it on charge overnight and today still 11.9. Had new battery fitted £117. Now whats the difference between petrol and diesel charger nothing surely.


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## freelanderuk (Jan 30, 2009)

Has the battery charger got a fuse somewhere , i tried to charge 2 different battery's and nothing so took them to the tip a couple of weeks later was looking at the charger and found a fuse underneath that had blown


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## blondy (Aug 23, 2007)

IT may be something to do with the output of the charger, most diesel engines have a larger batt due to the high compresion engine is harder to turn over, you may need something like a larger CTEC charger to do your batt justice, This is just a thought.


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## teal (Feb 23, 2009)

Thanks for replies guys, the fuse is ok so do not know why it does not charge.


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## trevorf (May 16, 2005)

There is no such thing as a "Petrol" or "Diesel" charger, its just an indication of the size of battery its suitable for. Diesels have a higher compression ratio than petrol so tend to need a larger battery for starting.

It sounds like your charger if duff but you need to check its output with a multimeter to be sure.


Trevor


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## Vennwood (Feb 4, 2007)

Have you tried cleaning the connections of both charger crocodile clips and battery. If the charger has been stood for a year or two it could have built up a corrosive film that is acting as a barrier to making a circuit.

On the other hand if the fuse is ok it could be duff as trevorf says


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## esdave (Jan 8, 2010)

hi to test your charger use a 12v 55w car bulb across this should give you 4.6 AMPS , half the amperage of your charger it should with bulb across still give you 13.8v if it is still 11.9 your charger is at fault if all connections ok it will be the rectifier that changes AC to DC .The voltage charging the battery must be approx 13.8v or it will not charge correctly , across the charger terminals with no battery connected you must have approx 14v. regards Dave


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## esdave (Jan 8, 2010)

hi just read your fault again you said 11.9v across your battery WITH engine running you should have 13.8v across or near, if not altenator or loose fan belt. dave


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