Give Me Power

[vmail]

for the 2NZ-FE

the standard Battery is 12V 36Ah

the max cranking amps is 97-119A

the alternator output is 70-90A, 12V @ 2000RPM

so my question is what is the largest(Ah) Battery I can use without upgrading the alternator

Note: I will be having two batteries if that makes a difference

[yvvan]

Doesn't matter,

Ah is just how long you can draw a certain amount of power from a Battery before it's flat (in this case 36A for one hour time or 1A for 36 hours of time).

Of course the larger Ah capacity Battery you use the longer it will take to fully charge it and that depends then on what RPM you run as that's what the output of the alternator depends on.

Cheers, Yves.

[jaxx]

using a small alternator on a big Battery is fine

itll just take yonks to fully charge it....

a bigger alternator likewise can be used with a small Battery

catch me drift?

[vmail]

so how long does it take for the alternator to charge the Battery ate 2000RPM?

[yvvan]

so how long does it take for the alternator to charge the battery ate 2000RPM?

Hmm, in an ideal world you could just use the alternator rating to calculate that it would be 1/2 hour, however when runing the car you are also using up power. With losses from the alternator itself, ignition, etc... and if your not running any fancy ICE stuff or so I would say it'll take about an hour or so to charge the standard Battery.

Cheers, Yves.

[vmail]

the ICE is a bit ill so thats not at full power

so if the 2nd Battery is the same spec it would take about 2hrs to charge both batteries

[yvvan]

Yeah, something like that.

Just keep in mind though that this will vary depending on tig factors.

Cheers, Yves.

[alanbradley]

and that depends then on what RPM you run as that's what the output of the alternator depends on.

With the revs Vmail claims he runs at it should be done in about 10 mins!

Only joking :)

Alan

[vmail]

free petrol has stopped now, so I will drive at lower speeds

[knightrider]

who sed anythink about how fast you drive alan was talking abouts revs so you could be in first doing 25mph