Voltage across battery when charging system is working normally???

[stradlater]

What voltage should I see across the battery when charging?

I think my alternator is actually working ok, because it runs at 11.8 and then drops a bit, goes up above 13 for a bit the back to sub 12. The back to 13 again. Is this normal?

[MWP]

See "Charging System" here http://gt4.mwp.id.au/training_manuals.html

[oldcorollas]

high 13's, low 14's is normal.

[TRD-12A]

Yeah 13.5v-14.5v is acceptable should'nt fluctuate as much as it is will drop slightly for a little bit when fully loaded(headlights,highbeam,blinkers, A/C)but then go back to normal

[stradlater]

Is 14.7 ok?

[ra28_miles]

14.7v is perfect. good healthy alternator

Turn all your lights on and acessories and check voltage.

Sub 12V then theres a problem

[stradlater]

Turns out, some C*NT at the wrecker I bought it off, sold me an engine which had been 'transfered' a faulty voltage regulator.

I opened it up, and all the bolts were even loose!!! SOOOO dodgy.

Won't be going back there ever again.

[TRD-12A]

14.7v is sweet a touch too high but good regardless

[ra28_miles]

what was the problem?

Overcharging, charge light coming on?

[stradlater]

Nah, quite the reverse.

I wasn't getting a charge light at all.

And yet it wasn't charging.

Then, it would randomly flash the charge light, then start charging, then stop immediately.

It basically fluctuated like that.

It was fucked.

Replaced the regulator (from one out of a beaten up corolla alternator or all things!), Cut my fingers several times, put it back in, and it was all good.

[chaserbuddy]

depends what battery you are using. 13.8v is minumum for any normal lead acid battery. Calcium/calcium batterys need slightly higher around 14.2-14.4v is recommended. If you run a diesel you wouldn't use a calcium/calcium battery as you will have problems as diesels do not charge that well with the alternator.

[toymaz]

depends what battery you are using. 13.8v is minumum for any normal lead acid battery. Calcium/calcium batterys need slightly higher around 14.2-14.4v is recommended. If you run a diesel you wouldn't use a calcium/calcium battery as you will have problems as diesels do not charge that well with the alternator.

What has a diesel have to do with charging?

[stradlater]

Yeah, what does it?

[PuttPuttBang]

would it have something to do with the fact that diesels usually only redline at like 4,000rpm?
but then again i dont think it would make any difference how fast ur engine spins

[TRD-12A]

nah it would'nt cause it's charging at idle the alternator would be doing less work at high rpm cause the regulator is controling the voltage