Have I got a Duff Battery (REFERENCE THREAD)

[The Hooded Claw]

Recently I have seen MANY threads on here asking if (Members) have a duff battery or Alternator & How do they check it

Well heres how to ..............

1/ With the engine off check and record the battery voltage with a Digital Voltmeter, should read between 12.4 & 12.8 Volts

2/ Start the engine and let it idle for 5 minutes, check and record the battery voltage. should read around about 13.5 to 13.9 Volts

3/ Get someone to Crank (start the engine) whilst you hold the voltmeter on the battery, Should read NO LESS than 11.0 Volts

A/ If the voltage at Step 1 is LESS that 12 Volts BATTERY IS DUFF Requires Changing

B/ If the Voltage at Step 2 is less than 12.5 Volts ALTERNATOR is DUFF Requires Changing

C/ If the Voltage at Step 3 is less than 11.0 Volts BATTERY is DUFF Requires changing


With Thanks to Mike Alder for his Input.


Keith

[migrator]

Not just good for funny tales, then!

[fowlerman]

Yes, he has got his uses.

Actually Keith, I've only today been trying to sort out a friend's Fiesta with exactly this problem. Pity you didn't post this earlier, now the chap next door, who's a technician at Stanways. has got all the kudos, cos he diagnosed it straight away. :Not_Impressed:

Pete.

[Thanatos]

I would just like to add if your getting voltages above 14.8v then you alternator will be bad and more then likely taken out the battery

As that's what mine did