[zuki]

Hi,
I have installed some months ago a Ford Alternator is my sierra.... I was wondering what is the MAX volts of charge the alternator should put out before it is going to stuff the battery up?

David

[Junior_91]

14.4 should be max mate.

[whincup]

my stock alt was putting out 14.8 at idle with everything else off for a while... told that was a bit high but not a problem. but its started dying over the last 2 months, probably not that much anymore...

[boballan82]

The standard tolerance for a voltage regulator is 14.5 v +/- .25. so 14.25 to 14.75 is OK. Over 14.8 V and your start to get gassing and loss of the acid.

When you charge a battery to full capacity with a battery charger it is charged to 15.0 volts to attain the correct specific gravity of the acid (1250 -1280)

[ras86]

it tells you on the top of the battery what they can handle too.

[boballan82]

The specs on top of the battery are the rated discharge rate or CCA (Cold Cranking Current), Zook charging tolerance as per the Suzuki manual is 14.5 +/- .3

Mine charges at 14.5 at 1500 rpm and 13.8 at idle.

[boballan82]

The old batteries used to be rated at Amp/Hr which was its Charge/Discharge rate over 5 hours. New Batteries are rated CCA which is the amount of Cold Starting Current. A good Starter draws about 50 - 80 amps on start and this increase as the bushes wear.