Alternator rebuild around Portsmout

[Alex_Blackwood]

The old split diode unit had a trait that was a pain - but in your case may be an advantage ... it caused a drop in actual voltage at the batterys by approx 0.5 - 0.7V ..... its why Sterling / Adverc and various created controllers to counter it ...

Basically the alternator was thumping out its 14.5+ V to the diode box ... the diodes caused a drop in voltage and batterys were never fully charged .... so we had a choice - fit a Sterling or other box that was battery sensed - to beat the alternator ... or alter the alternator itself.

For your setup - just the Diode box would do the job you want .... reckon you could find one cheap in a yard ... I have one not used still in my engine bay - but I'm in Latvia so not much use to you ... sorry.

he doesn't say what his charging system is, nor does he say what voltage he is actually getting at the battery. Does he already have a split diode ? where is the sensing taken from? etc. etc. He may not need to have anything done to the alternator at all! I would like to see what the voltage at the battery terminals is. Lots of possibilities.

 

[Refueler]

he doesn't say what his charging system is, nor does he say what voltage he is actually getting at the battery. Does he already have a split diode ? where is the sensing taken from? etc. etc. He may not need to have anything done to the alternator at all! I would like to see what the voltage at the battery terminals is. Lots of possibilities.

Lets quote then ?

"I have a rebuilt alternator that puts out a rather ambitious 14.3v. The guy who rebuilt it (now retired) said the higher voltage is good for dealing with voltage drops on boats"

is that enough ? Putting a split diode box in the system will drop to the voltage he then goes on to want ....

TBH - personally - I think he's overthinking and reacting to it ....

 

[Alex_Blackwood]

Lets quote then ?

"I have a rebuilt alternator that puts out a rather ambitious 14.3v. The guy who rebuilt it (now retired) said the higher voltage is good for dealing with voltage drops on boats"

is that enough ? Putting a split diode box in the system will drop to the voltage he then goes on to want ....

TBH - personally - I think he's overthinking and reacting to it ....

If he already has a split diode then the battery terminal voltage will be around 13.7/8. if the alternator is machine sensed. If the alternator is battery sensed from the output side of the diodes then it will be 14.3 v. If he has a VSR then it could be some other value nearer 14.3v. He does not say where he is measuring the alternator voltage from.
Like you I think he his overthinking etc. However if we explain some of the possibilities, of which he may not be aware, it may put his mind at rest.

 

[Refueler]

If he already has a split diode then the battery terminal voltage will be around 13.7/8. if the alternator is machine sensed. If the alternator is battery sensed from the output side of the diodes then it will be 14.3 v. If he has a VSR then it could be some other value nearer 14.3v. He does not say where he is measuring the alternator voltage from.
Like you I think he his overthinking etc. However if we explain some of the possibilities, of which he may not be aware, it may put his mind at rest.

I agree with you - but I tend to think that when someone asks such a question as OP has ... then its unlikely he has any techy upgrade to the gear ..

Personally - the last thing I would want to do is start mucking about with the alternator itself ... as a standard alternator is expected to put out ~14.5V.

According to many online sites AGM should be charged at ~14.4V ... so OP IMHO is possibly worried for nothing ...

eg:

Charging batteries | Mastervolt

 

[Alex_Blackwood]

I agree with you - but I tend to think that when someone asks such a question as OP has ... then its unlikely he has any techy upgrade to the gear ..

Personally - the last thing I would want to do is start mucking about with the alternator itself ... as a standard alternator is expected to put out ~14.5V.

According to many online sites AGM should be charged at ~14.4V ... so OP IMHO is possibly worried for nothing ...

eg:

Charging batteries | Mastervolt

YUP! Also while he is using his batteries, albeit not the start battery, they will not actually be on "Float" as such. Again a lot depends on system. But I reiterate we don't know his system. Granted the question was only about the alternator but it did raise the other questions in my mind. Perhaps he will enlighten us.

 

[samfieldhouse]

Just to update this: I'm now using Royle Jackson Ltd in Southampton. A new solenoid and general refurb of my starter and a good sorting of my alternator came in at £160.

 

[Airscrew]

It looks like you are well sorted, but for the record, and others, we have used Mike at JASM near Botley, Southampton.

Just Alternators & Starter Motors - Repairing, reconditioning and servicing alternators and starter motors

The most amazing collection of marine things electrical, and has fixed / serviced both alternator and starter motors at very affordable rates for me.

Google thinks he is closed.
Has anyone used him recently??

 

[samfieldhouse]

It looks like you are well sorted, but for the record, and others, we have used Mike at JASM near Botley, Southampton.

Just Alternators & Starter Motors - Repairing, reconditioning and servicing alternators and starter motors


The most amazing collection of marine things electrical, and has fixed / serviced both alternator and starter motors at very affordable rates for me.

Google thinks he is closed.
Has anyone used him recently??

JASM still going near Hamble Country Park as far as I know.