Here is how to increase the charge voltage of alternator

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
alternator outoput

Try a good auto electrican we used to Delta wire alternators that nearly doubled the output :dance: and sometimes you needed to upgrade the regulator but it was a very easy job to do :)
Cheers
Peter & Ronie B
 
Good article but the other thing I think is perhaps more important is to change the pulley to the smallest possible. We have 2 5/8" if I remember correctly (not at the boat) and they work perfect. This compensates for the much slower rpms we cruise at (1400). Belt wear or dust has been no problem. Do be sure and use a notched top quality belt especially if you go smaller.
 
Alternator cooling is RPM related.

High output with low RPM may Chernoble.
 
I stumbled over this excellent article about how to change the charging voltage of an alternator - and thought it would be a benefitial for many members:

SmartGauge Electronics - Increasing alternator charge voltages

There are many other good articles on this site.

Why not have the internal reg removed and the Alt converted to external control? $50 - $75. Then use an external regulator like the Balmar ARS -5 and be done with it with in a few hours and for about $300. No guessing no taking the Alt apart three times. The ARS series are adjustable to what ever out put you may need.
 
I've got to wonder - If it's so easy to raise the output of an alternator, why don't they just make them like that in the first place?
 
The hassle here is you are mixing cars , trucks and boats.

Sure 13.5 or .8 may be too low for a car that is not driven that much , but on a boat boosting to 14.4 to get a great charge will simply boil the batteries after a few hours.

The better solution is a modern alt for your car , and almost anyone's SMART 3 or 4 stage reg on a nice big alternator.

Usually folks are too lazy to build a big strong bracket for a HD alt , and install a pair of belts to run it.

If you can do almost all the DC charging from the engine , no need for the noisemaker to grind away.

If you use the noisemaker , a SMART V reg and a 150A + alt will fill batteries loads faster than a 150A "rated" battery charger, esp with an under 10KW noisemaker.
 
, "have any recommendations for a 350 Chevy based gasser?"

Really depends on how you cruise and what you need.

For many folks a visit to NAPA will find an alternator of 65A with factory setup for an external regulator that bolts right in.

These were used in "big" cars Caddies and some Olds back in the 60's or 70's and are still stock items, and at times can be had for cheap rebuilt , $35 -40 exchange on sale. Autozone vs Advanced in the local paper.

Your favorite 3 stage V reg will hook up easily and the cruise speeds of most gassers is high enough for good cooling..

Look at the front of the alt and be sure the cooling fins are at an angle not at 90deg to the shaft.

The 90 are "universal " and don't cool as well as the angled fins.

The annoying car music folks , you know the kids with amps in the trunk blasting for 1/2 mile with base that cracks concrete , is also a source for drop in alts with loads more power.Use the marine regulator not a built in.
 
Last edited:
, "have any recommendations for a 350 Chevy based gasser?"


For many folks a visit to NAPA will find an alternator of 65A with factory setup for an external regulator that bolts right in.

QUOTE]

Do not buy an alternator from NAPA and put it in a gasoline engine compartment ! To put anything but a marine "ignition protected" alternator in there is extremely dangerous.
 
Do not buy an alternator from NAPA and put it in a gasoline engine compartment ! To put anything but a marine "ignition protected" alternator in there is extremely dangerous.

Very important and very good advice. Anything electrical in a gasoline engine room or compartment must be ignition protected and should be labelled as such.
 
Back
Top Bottom