New alternator

Sep 7, 2009
74
O'Day 1987 272Le Lake Arthur, Moraine State Park Portersville,Pa.
I own a 1987 O'Day 272le and the alternator is failing. Should I replace the alternator with the original equipment size or get a higher capacity alternator?
 

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
What size alternator? What size battery bank? Do you draw down your battery (or batteries) very often?
Hod id you determine you alternator is "failing"?
 
May 24, 2004
7,129
CC 30 South Florida
It depends on your needs and type of sailing. Bigger is not necessarily better. How much horsepower your engine has? Alternators divert engine horsepower to the production of electrical power; the bigger the alternator the more horsepower it takes from the engine. For every 25A the alternator requires 1 horsepower; in a 10hp engine that is 10% of total engine power that will not be available for propulsion.
 
  • Like
Likes: jssailem
Dec 5, 2015
114
Oday 272LE Louisville, KY
I own a 1987 O'Day 272le and the alternator is failing. Should I replace the alternator with the original equipment size or get a higher capacity alternator?
Chuck:

I have a 272LE with the Universal M 12 diesel. I had my 35amp (Motorola) alternator rebuilt for about $75.00 at an auto-electric shop. I re-routed the output directly to the batteries (2 group 31 wet cell batteries) with a new #4 awg wire with a Blue Sea ACR and a large fuse. I do not have an on-board charger nor do I use shore power. My batteries stay at 12.7 - 12.9 volts without any problems. My diesel engine runs 1-2 times per week.
 
  • Helpful
Likes: jssailem
Sep 7, 2009
74
O'Day 1987 272Le Lake Arthur, Moraine State Park Portersville,Pa.
Thanks for all your help. I have to do more research on my engine.