Non-Mercedes Alternator Question

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MB Enthusiast
May 16, 2005
This and that.
If my car has a 80A alternator fitted, and it needs replacing, what are the advantages/pitfalls of fitting a 100A in its place?


No pitfalls (ensure your connections are clean, and make good contact)

Advantage is that you could add more equipment without the risk of not supplying enough charge to the battery. (spotlights, super duper loud stereo, neons under the car etc etc) (God help us)

You may also find that the battery will be recharged a little more quickly should you allow it to get discharged.

tbh in the real world it won't make much difference unless you need one, and can get it cheaper than an 80 amp.
Assumoing no losses 80 amps = about 1000 watts
100 amps = 1200 watts.
Now when are you going to use all of that? :D
Thanks Ted. I didn't want to be blowing my regulator or anything.

I don't want to add any kit to the car, but if I can get an 80A for £30 and a 100A for £30, then I'm going to want the bigger one, ain't I ;)

Yup, I'd go for the bigger one.
An alternator regulator regulates on voltage, not current (car alternators are intrinsically self current regulating) so you will not blow your reg.
And I thought all modern alternators had inbuilt voltage regulators?
Ahhh, who remembers the old 4TR reg.. (where's Television when you want to remenisce?)
And I thought all modern alternators had inbuilt voltage regulators?

They do.
It will be the regulator or brush [pack that has gone anyway, the basic windings virtually never go faulty.

What's the problem Doofus.?
Dieselman said:
What's the problem Doofus.?

The battery lost charge. Possibly over time, possibly all at once. I used the car on Friday, all was fine, although the car's always been a bit sluggish on first turn of the key. The on Saturday, battery was dead (7.4v). So I whopped a new battery in, and I've got a 100A alternator lying about, so I thought I might as well stick that on too, as long as it was safe, which it seems to be.

Having done that, I can get the old one tested and the brushes renewed as necessary at my convenience.

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