Hi folks

aollaku · May 19, 2014

Hi folks. i have a p38 1996 4.6 hse. I have changed the battery and i put a 110A, but my alternator is 100A. There is any problem with this?? Could cause something undiserable for the system???

Im using this battery about 1 year

.

ady014 · May 19, 2014

No issue at all. Battery is measured on it's ability to provide power so a 110 ah battery can provide a 110 for one hour before dropping below 12v. The alternator is measured on its max output generally a little more than the car consumes with all electrics switched on.

General rule is put the biggest battery that will fit in the hole it will last longer as it isn't being used as hard.

aollaku · May 19, 2014

And for the alternator there is no problem to charge the battery even where is under the value....

Saint.V8 · May 19, 2014

aollaku said:
And for the alternator there is no problem to charge the battery even where is under the value....

Should be no issue....

As above, the Alternator will output 100A to run the vehicle services...part of this is a handful of amps to charge the battery....

You would certainly never bung 100A into a battery...the poor thing would go bang regardless of size!!

Case in point is your standard overnight battery charger...that will charge a 110A battery in 16hours as it only outputs 7-8A max....and that is all your Alternator will supply to your battery too....(which is why a 15minute round the block run won't charge a flat battery!)

StuckAgainSteve · May 19, 2014

It's not the amps you need to be worried about. If you've put a modern lead calcium battery in, it'll never be fully charged anyway as your older alternator will probably output insufficient voltage to charge it fully. Modern "calcium" batteries like ~14.4 volts to charge properly - older alternators often output 13.8 Volts - being a 1996 car I wouldn't be surprised if it's the older type. Still, a 90% charged 110ah batter will have plenty of reserve.

wammers · May 19, 2014

No problem, later 4.6 V8s have an 150 AMP alternator a 14.5 volt controller and a 75 AMP battery. Your 100 AMP unit will more than likely have a 14.2 volt controller. Battery AMPS are irrelevant as far as charging goes.

Datatek · May 19, 2014

StuckAgainSteve said:
It's not the amps you need to be worried about. If you've put a modern lead calcium battery in, it'll never be fully charged anyway as your older alternator will probably output insufficient voltage to charge it fully. Modern "calcium" batteries like ~14.4 volts to charge properly - older alternators often output 13.8 Volts - being a 1996 car I wouldn't be surprised if it's the older type. Still, a 90% charged 110ah batter will have plenty of reserve.

14.2 volts is really the minimum, 14.8 volts absolute max.
All P38's as far as I'm aware had 14.2 volt regulated alternators as original fitment regardless of the amperage.

Hi folks

aollaku

Active Member

ady014

Active Member

aollaku

Active Member

Saint.V8

Dyed-in-the-wool 100% RR Junkie

StuckAgainSteve

Well-Known Member

wammers

No longer with us, RIP

Datatek

Well-Known Member

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