FIAT Punto - Battery charge

Honest John Back Room » Technical matters
View Threaded
Sun 5 Feb 2012 16:01
FIAT Punto - Battery charge - Chris M
What does the little green indicator on the battery tell me? According to the label, green means it's charged.

However, for the past few weeks the car has been turning over a bit slowly in the mornings. The colder it's been, the slower it turns. The car has always started very easily, firing up after only a second or so and it hasn't let us down - yet! Today I got the multimeter out. 12.2v first thing before I tried starting it (the car is garaged, the temp was about 10 degrees C) and 14.15v once it was going. This dropped to 13.98v with headlights, front fogs and HRW on, so the alternator is working. The earth is OK too with no resistance between the earth terminal and body or engine. Cranking for 15 - 20 secs got the volts dropping to just over 9v and you could hear the battery starting to die. So I'm thinking the battery is on the way out. It's seven years old so it is about that time.

The thing is, throughout all of the above, the little indicator has shown green - "Charge OK". What makes the indicator work? Is it measuring the specific gravity and if so, does that not drop as quickly as the volts?
Reply | Report as offensive | Link
Sun 5 Feb 2012 18:01
FIAT Punto - Battery charge - Peter.N.

I would say you need a new battery, It can still be fully charged but be low on capacity, your charging system sounds healthy enough.

Reply | Report as offensive | Link