How long can an alternator be expected to last?

[Theo]

My alternator has done rather more than 5,300 hours.  Should I think of prophylactically changing it?  It's a 90A Bosch.

 

 

[Alan de Enfield]

42 minutes ago, Theo said:

My alternator has done rather more than 5,300 hours.  Should I think of prophylactically changing it?  It's a 90A Bosch.

 

 

The 70a on my Lister had done well over 10,000 hours when we sold the boat.

 

Buy a spare and keep it in the JiC cupboard but be prepared to never use it.

[Chewbacka]

Interesting question.  I thought as they are typically used on cars, and as a diesel car engine has a life expectancy of say 250,000 miles then at an average of 45mph it would have a design life of at least 250000/45= 5500 hours.

 

However being Bosch it may be more.  That said, electronic bits can last forever (or just fail without warning), it’s the mechanical bits that wear.  So if the bearings are good, I would leave it alone, but that is just me.

[Keeping Up]

Our first alternator lasted 8000 hours, then the diodes and regulator died when it overheated due to dog hairs in the vent slots. Their replacements lasted 4000 hours. Their replacements lasted 2000 hours, and then 1000 hours. 500 hours later I bought a new alternator.

 

A lot depends on how hot it gets. I'm hoping that mine will have a long life because I've got a bilge blower aiming a stream of cold air at it.

[Theo]

Thanks all.

 

Perhaps a spare for the JiC locker is a good idea.

 

N

[Alan de Enfield]

1 minute ago, Theo said:

Thanks all.

 

Perhaps a spare for the JiC locker is a good idea.

 

N

 

 

[roland elsdon]

If you buy a spare you will give it away with the boat, if you dont it will fail in the worst place leaving you in the lurch.

 

its a boat they are like that.

[zenataomm]

4 hours ago, Theo said:

My alternator has done rather more than 5,300 hours.  Should I think of prophylactically changing it?  It's a 90A Bosch.

 

 

I've got to ask, or it'll drive me crackers (more crackers?) 

By prophylactically, is it another way of saying "preventing, just in case" or "protecting because it could happen"?

Or has Spell Checker struck again?

[Theo]

AFAIK it could be used in either sense but to put yu out of your misery I will check... 

[sharpness]

Didn't French Letters used to be called prophylactics???

[Chewbacka]

2 minutes ago, sharpness said:

Didn't French Letters used to be called prophylactics???

I think proactively is a more common word for pre-emptively replacing an old, ok item, but maybe not....

[Machpoint005]

12 hours ago, sharpness said:

Didn't French Letters used to be called prophylactics???

 

The French call them preservatifs.

[Captain Fizz]

16 hours ago, Keeping Up said:

Our first alternator lasted 8000 hours, then the diodes and regulator died when it overheated due to dog hairs in the vent slots. Their replacements lasted 4000 hours. Their replacements lasted 2000 hours, and then 1000 hours. 500 hours later I bought a new alternator.

 

A lot depends on how hot it gets. I'm hoping that mine will have a long life because I've got a bilge blower aiming a stream of cold air at it.

Why did you replace the dog hairs??

[Keeping Up]

41 minutes ago, Captain Fizz said:

Why did you replace the dog hairs??

The dog was getting cold without them

[Theo]

On 29/07/2019 at 22:29, sharpness said:

Didn't French Letters used to be called prophylactics???

They did indeed.

On 29/07/2019 at 22:34, Chewbacka said:

I think proactively is a more common word for pre-emptively replacing an old, ok item, but maybe not....

"Proactively" is a modern word.  Definitely to be eschewed.

 

[Chewbacka]

34 minutes ago, Theo said:

They did indeed.

"Proactively" is a modern word.  Definitely to be eschewed.

 

Only if you are Jacob Rees-Mogg

Edited July 31, 2019 by Chewbacka

[reg]

10 hours ago, Theo said:

They did indeed.

"Proactively" is a modern word.  Definitely to be eschewed.

 

Never mount your alternator eschewed as it will wear out the bearings

[Alan de Enfield]

43 minutes ago, reg said:

Never mount your alternator eschewed as it will wear out the bearings

And, you may even get the fan-belt eschewed up.