Bosch alternator installation warning tag, Addendum to an old thread, too lazy to look for it Options

[Cap'n Krusty]

In an off the wall reply to a transmission linkage lubrication suggestion I made over on The Bird, I was challenged to supply proof for an assertion I made in an old thread here (!) regarding possible alternator damage from jump starting a car with a dead battery. As the alternator in a car is intended to function primarily as a battery maintainer, NOT a battery charger, Bosch has seen fit to include a warning label or tag with every new or remanufactured alternator they sell. I think it's reasonable to assume they have some valid reason to supply us with that warning, and to extend that wisdom to a dead battery situation leading to the necessity for a jump start.





Some folks have a long memory for things that, for whatever reason, offended them. Because I've been challenged to provide a reason for my earlier statement, which I fully stand behind, I've searched the web for an image of that warning tag. After reading the tag, the person challenging my advice is, of course, free to do exactly as he wishes. Frankly, Scarlett, I don't give a damn. If risking a new alternator, which can be priced at thousands of dollars (yup, and that's in US money!) is what he, or anyone else chooses to do, please be my guest! If this person's engineering department comes up with peer reviewed double blind test results that disprove Bosch's advice, I'd be happy to issue a public apology and review my opinion. Until that happens, I'll err on the side of caution, and do it the right way as I see it.

See, Krustiness AND politeness in the same post! Betcha you didn't see THAT coming!

The Cap'n

[stugray]

Just to revisit this discussion:

A Bad alternator can kill a good battery.
AND a Bad Battery can kill a good Alternator.

My friend at work just went through this with his Lexus:

Car kept dying acting like battery was dead.
Dealer:
Replaces Battery - Battery still goes dead
Replaces Alternator - Battery still goes dead
Replaces Alternator - Battery goes dead
Replaces Battery - Battery goes dead
Replaces Battery AND Alternator - Car is now fine.

First time they replaced the battery, the Alternator was bad, so new battery is stressed and runs down and is damaged
Replace Alternator (with Bad Battery) Kills Alternator
Replace Alternator again ( with Bad Battery) stresses Alternator again
Replace Battery, but Alternator is now bad, drains Battery & ruins it.
Replace Battery AND Alternator at the same time - All is good.

SO here is a perfect example where installing a brand new alternator with a drained battery can ruin a good alternator.
And replacing a battery with a bad alternator can ruin a battery.

SO - Bad alternator designer!

The Cap'n is correct - do not ask an alternator to charge a dead or bad battery if it can be avoided.